AIX Interview Questions :

AIX Interview Questions :

There is a certain amount of overlap between these questions. The interviewer should not ask them all, but ask a sufficient variety of questions to ascertain the applicant’s knowledge of both AIX in general and the interviewer’s operating environment.

Basic Hardware, AIX, and other Applications

Question: What levels of AIX have you worked with?
Answer:
 AIX 4.3.3 and AIX 5.1 good
 If only AIX 4.2.1, 4.1, or 3.2, bad

Question: What types of machines have you worked with?
Answer: Look for questions pertaining to the hardware, to ascertain level of competence and understanding.
 Take note of applicants who mention older technologies like “SP2” or newer technologies like “Regatta”

Question: What applications have you used with AIX?
Answer: Look for applications like HACMP, ADSM/TSM, SAP, i2, Manugistics, MQ Series, WebSphere, etc.
 An applicant with considerable HACMP experience is likely to have quite a bit of AIX knowledge, especially LVM, disks, general TCPIP, and application enablement.


User Management

Question: Suppose that there are some users that need to run certain commands normally only accessible by root. How would you grant them access?
Answer: sudo
Question: Discuss your philosophy on granting user access to root or to an application user ID.
Answer: For root, prefer to 

Base Kernel

Question: The system is performing very slowly; you have discovered that this is due to an increasing number of defunct processes are being created. How can you determine the cause?
Answer:
1. Check to see if new defunct processes are being created, owned by the init process, with no processes being deleted at all.
2. If some defunct processes are being cleared out and the overall number of defunct processes is still growing, then this is due to an application creating more defunct processes than the init process can clean out. 
3. However, if NO defunct processes owned by init (PID 1) are being cleared out, this points to an incorrect wait entry in the /etc/inittab file. The init process is stuck on this wait entry and will not cycle through the defunct processes until that entry finishes. The solution is to change that “wait” entry to a “once” entry.

Question: You get a message that the system can’t fork any additional processes? What do suspect to be the problem?
Answer: Either paging space is full or maxuproc (maximum number of user processes) is set too low.

Question: You’re running some commands and getting an error that says “srcmstr daemon is not running”. Obviously, it is, because the machine appears to be functional. What is the likely cause? 
Answer: Someone has updated some of the base kernel filesets without rebooting the machine.

Question: How do you run 64-bit applications on AIX 4.3.3? On AIX 5.1? What else might you have to consider on an AIX 5 machine?
Answer: 
• AIX 4.3.3 only comes with a 32-bit kernel, so you need to ensure that 64-bit application support is enabled (via the load64bit entry in /etc/inittab or done via SMIT).
• For AIX 5.1, either use the same method as AIX 4.3.3 OR configure the system to use a true 64-bit kernel. If you use a true 64-bit kernel, any 32-bit application will NOT run.
ODM

Question: Describe one situation where it might be appropriate to edit the ODM.
Answer: E.g., need to make parameter changes to a device that is open, and that cannot be modified without closing the device (i.e., a network device), and where the machine can be easily rebooted following the change.

Question: Describe how to manually edit the ODM. What commands should be used?
Answer: 
1. Use the odmget command to grab the appropriate entries from the ODM, into a text file. 
2. Edit these entries. 
3. Use the odmdelete command to delete the current entries.
4. Use the odmadd command to add the new entries.
5. If these are device configuration files, use the savebase command to save them into the boot image.

Question: When might the savebase command be used?
Answer: After making manual changes to the CuAt, CuDv, CuDvDr, CuDep, or CuVPD ODM classes (aka the device configuration database), these classes must be saved into the boot image in the boot logical volume. If they are not saved, there is a risk run that the changes won’t be saved at boot. Note that the chdev command (and others) will cause savebase to be run.

Booting

Question: What key would you use at boot time to signal the machine to boot into service mode?
Answer: F5 or 5 will signal the machine to boot from the internal boot list. F1 or 1 will bring the machine into SMS mode. The F[x] keys are used for graphical consoles; the others are used on ASCII consoles.

Question: What is the effect of setting the normal mode bootlist to cd0 first and hdisk0 second?
Answer: The machine will boot from the CDROM into maintenance mode automatically if a boot CD has been inserted. If not, the machine will boot from the disk into normal mode.

Question: A machine hangs at boot because the network is inaccessible or an NIS server is accessible. How can you recover?
Answer: With inaccessible network (LED 581 for a long time), the machine will generally recover after timing out. With a NIS problem, probably have to boot into service mode

Disk Device Configuration

Question: You are adding a number of new internal SCSI disks to a pSeries 680 and a new drawer of SSA drives. How does cfgmgr operate different when configuring each?
Answer: Internal SCSI drives are discovered one at a time by order of their SCSI ID (i.e., their slot location). SSA drives are discovered by their SSA serial number, which has nothing to do with their slot in the drawer.

Question: After a reboot or after running cfgmgr, a particular disk is listed twice. Give some possible reasons why and how you might narrow them down.
Answer:
1. The disk can be detected, but it has failed and since cfgmgr can’t verify the physical volume identifer, it marks the old disk Defined and then creates a new disk entry with no PVID.
2. You are running in a multi-path (either SAN or twintailed SCSI) environment and the system is (properly) seeing the disk multiple times.
• If one disk is Defined and the other Available, or lspv shows the second instance as having no PVID, then it’s probably #1. Also check the error report.
• If the disk is seen as being Available twice (and lspv lists it twice), it’s probably #2.

Question: What considerations must you give when creating RAID-0 or RAID-1 disks in an SSA array?
Answer: You cannot cable RAID-0 or RAID-1 arrays such that there are multiple adapters in the loop (as opposed to RAID-5).

Question: What’s the difference between RAID-0 and RAID-1?
Answer: RAID-0 is hardware striping. RAID-1 is mirroring.

Question: When using an SSA array, what are the tradeoffs to consider between using a large RAID-5 array and using LVM mirroring?
Answer: RAID-5 would waste fewer disks, but it would be slower.

LVM/JFS

Question: How do you properly mirror rootvg to protect the OS from crashing should a disk fail?
Answer: 
1. Use the mirrorvg command to mirror the logical volumes
2. Run the bosboot command to reboot the boot image and update the disk boot record on both disks that contain a copy of the boot logical volume.
3. Run the bootlist command to add both disks to the boot list.
4. Mirror all non-rootvg paging spaces as well as those in rootvg.
Dump device?
Paging space? 

Question: Why is it important to mirror non-rootvg paging spaces, and what might be the effect if this is not done?
Answer: The OS allocates pages in a round-robin fashion across all paging devices. If a non-rootvg disk containing a paging space fails, the system will likely crash unless it is mirrored. Putting paging spaces on RAID disks is not recommended due to the performance implications.

Question: What kind of considerations can be made with regard to mirroring rootvg in a non-mission critical environment where maximizing disk space is important?
Answer: You might be able to get away with not mirroring any paging spaces, the boot logical volume, or any non-critical file systems. If a disk crashes, you might have to perform some maintenance in service mode.


Question: Provide the steps to move a file system from one volume group to another WITHOUT recreating and restoring it.
Answer:
1. Unmount the file system
2. Use the cplv command to copy the logical volume to the new volume group.
3. Use the chfs command to update the dev and log entries for the file system.
4. Run fsck.

Question: Why is directly editing /etc/filesystems, to change information for a file system, a bad idea?
Answer: The entries from /etc/filesystems are usually stored in the logical volume control block for each logical volume. If you ever had to run importvg for this volume group (i.e., after a reinstall or if using HACMP), the changes would be lost.

Question: You can’t unmount a file system (AIX says it’s in use). How do you determine what process is keeping it open?
Answer: fuser or lsof.

Question: The “df” command shows that the file system is 100% full, but “du” shows no files in the file system. Why, and how do you debug this?
Answer: A running process is holding open a file descriptor that references a large amount of space either not saved as a file or references a file that has been deleted. Use “lsof” or “fuser” to track down this process.

Question: The “df” and “du” commands indicate that the file system is 50% full, but you notice that the total size of all files, as given by “ls” is greater than the size of the file system. How is this possible?
Answer: These are sparse files, where the size of the file is larger than the amount of space it takes up. The file contains a large of “null blocks”.

Question: What steps should you follow to replace a failed hdisk?
Answer:
1. Remove all allocated logical volumes (if not mirrored) or LV copies (if mirrored).
2. Remove disk from the volume group.
3. Remove disk definition (and pdisk, if it’s an SSA drive mapped 1-to-1)
4. Physically replace disk
5. Run cfgmgr.
6. Add disk to volume group and recreate LVs or LV copies.

Network

Question: Basic network configuration
Answer: "smit mktcpip"?

Question: What file is used to tell AIX to use local /etc/hosts entries instead of DNS?
Answer: /etc/netsvc.conf. Specifically, the entry is “hosts=local,bind”.

Question: There is a conflict between a machine’s IP address and the DNS entry. Unfortunately, the DNS server is a Win2K server managed by a little old lady who works once a week. How do you get around this?
Answer: Put an entry in /etc/hosts, and then use /etc/netsvc.conf to force AIX to read /etc/hosts first.

Question: You’ve properly exported a file system on a server. You’ve properly set up the NFS file system definition on the client, and the proper daemons are running. However, when you try to mount it, you get an error:
mount: 1831-009 aixnim not in hosts database
mount: 1831-008 giving up on:
aixnim:/nim
A route to the remote host is not available.

What two options do you have to resolve this?
Answer: 
1. Check /etc/resolv.conf for an entry to the appropriate nameserver.
2. Add it to /etc/hosts.

Question: What is resolv.conf used for?
Answer: To provide a list of nameservers and domains to search for hosts.

Question: Your machines are in the xyz.com domain. You want to be able to look up hosts in the abc.com domain. What should you do so that the ping command will find a route to those hosts?
Answer: 
1. Add the nameserver for that domain to /etc/resolv.conf.
2. Make sure you have a route to those nameservers.

Question: Where is the default gateway stored in AIX? Where are other routes stored?
Answer: As ODM entries in the CuAt ODM class.

SMIT

Question: How would you use SMIT to create scripts for future use?
Answer: Use the script.script file for commands that have been executed. Or, use the -x flag with smit.

Question: You’re using SMIT and are getting a strange error during its execution. How do you debug what SMIT is doing?
Answer: Use the -D flag on SMIT, and look at the smit.log file for the AIX commands being executed by SMIT and the error messages being generated.

Performance

Question: A project manager claims that a system is CPU-bound. What commands do you run to verify this, and what sort of output are you looking for? 
Answer: 
1. Run vmstat and look at the wait, idle, CPU utilization, runq and blockq parameters. 
2. A CPU-bound system will exhibit relatively low wait and idle percentages and a high degree of CPU usage. 
3. In addition, the runq parameter will average the number of CPUs on the system and the blockq parameter will be, on the average, high.

Question: You have a 32-way Regatta. Why is vmstat not an accurate tool to measure CPU utilization for each processor?
Answer: vmstat takes a system average. The sar command can show the CPU utilization for a particular processor.

Question: If you have Workload Manager policies defined for several classes of processes, and the machine is under little load, what happens?
Answer: Nothing. WLM policies are not enforced until there is contention for resources.

Installation Issues

Question: What is the difference between a migration install, a preservation install, or an overwrite install?
Answer: 
• A overwrite install recreates rootvg and the file systems and installs everything from scratch. Other non-OS file systems are deleted.
• A preservation install preserves rootvg. It only overwrites the base OS (to the base level from the installation image) and thus only affects /, /usr, /var, and /tmp. Your own modified config files are generally saved to a special location and can be recovered.
• A migration install is used to take an existing AIX machine to a new AIX level (i.e., 4.3 to 5.1).

Question: You need to update an AIX 4.3.2 machine to AIX 4.3.3. How do you do this?
Answer: Take the AIX 4.3.3 CDs and perform an “update_all”.

Question: Define under what circumstances two different versions of a product can coexist on the same machine in AIX.
Answer:
1. The names of the filesets for that product are different when stored in the ODM.
2. The product does not store names in the ODM.

Question: What considerations do you need to make when cloning system X to system Y?
Answer: Make sure that all the drivers needed for system Y and its associated hardware are included in the image for system X.

Question: A user wants you to install some set of commands on system X; these commands already exist on system Y. How would you tell which filesets to install?
Answer: Run “lslpp -w ” to see what fileset provides that command.

Question: You’ve installed a new fileset. How do you tell which files are provided?
Answer: Run “lslpp -f ” to see what files are installed by that fileset.

AIX Patches and Maintenance

Question: Discuss your strategy for applying and committing maintenance
Answer:
• A prudent administrator will generally apply fixes first if those fixes have never been used before in the environment.
• After an evaluation period, the fixes can be committed.
• Subsequent installations of those fixes on other machines can then be committed.
• If these fixes are related to the base OS, a mksysb should be created first.

Question: What are the AIX Maintenance Levels and how do they differ from normal fixes?
Answer: AIX Maintenance Levels are similar to an NT service pack. They are generally considered safe to install “all at once”. Normal AIX fix collections may or may not contain fixes that could interfere with each other; however, maintenance levels are generally considered safe.

Question: Describe the difference between a PTF, and APAR, and a maintenance level.
Answer: An APAR is a specific patch that may update one or more filesets. A PTF is an IBM term for a collection of APARs commonly shipped together as a common fileset update. A maintenance level is a collection of APARs (also generally ordered as an APAR).

Question: Your machine is running AIX 4.3.3 with maintenance level 10 applied. “oslevel” (no option) reports “4.3.2.0”. Why?
Answer: There are some filesets installed that are at a level BELOW what is defined for 4.3.3.

Question: What is the difference between applying and committing an APAR?
Answer: Applying it saves the old versions of the files so that you can back off the new version. Committing the APAR removes the old versions.

Question: How do you back off a committed set of patches?
Answer: You have to forcibly install the base level of the affected filesets, while NOT reinstalling any prerequisites, and then re-patch back to the appropriate level.



Question: You’re installing a new IBM 6228 fiber card into an existing 4.3.3 system for the first time. What problems might you encouter?
Answer: The AIX 4.3.3 CDs don’t provide any base support for IBM 6228 fiber cards. You must download the drivers in the form of an APAR and install them separately. AIX 5.1 provide fiber support in the base CDs.

Misc. / Other Products

Question: What TERM setting would you use on an IBM 3153 monitor?
Answer: ibm3151

Question: List some common sites to download freeware tools for AIX?
Answer: aixpdslib.seas.ucla.edu
purdue.edu
www.bullfreeware.com
IBM repository of Linux freeware for AIX

Question: A group of developers wants to know if they will be able to install different versions of the Java runtime on a machine. Specifically, they want to install the base level filesets for versions 1.2.2, 1.3.0, and 1.3.1, as well as a separate set of patches. What do you tell them?
Answer: JDK/JRE 1.2.2, 1.3.0, and 1.3.1 can all coexist on a machine, as they are completely separate sets of filesets. However, patches for these versions cannot coexist with the base levels.

Question: Versions 3.6.4 and 3.6.6 of the IBM CSet++ compiler are comprised of the same basic set of fileset names, meaning that they normally cannot be installed on the same machine at the same time. What solution (unsupported by IBM) do you suggest? What considerations must you give to this environment?
Answer: Install the second set of software on a second machine. Take all the files installed by those filesets and copy them to the other machine into another directory. The ODM will not recognize that the second set of filesets are installed, but the product will still be functional. Note that this is unsupported by IBM, but there’s a fine line between “unsupported” and “functional”. Note that you can’t very easily apply patches to this environment.
Question: What does the LIBPATH variable do?
Answer: It controls the order in which libraries will be discovered so as to arbitrate between libraries with the same name.

Question: When IBM some particular sequence of commands or environment is “not supported”, what do they mean?
Answer: That it may work, but that won’t SUPPORT it because they haven’t TESTED it.

HACMP interview questions

a. What characters should a hostname contain for HACMP configuration?
The hostname cannot have following characters: -, _, * or other special characters.

b. Can Service IP and Boot IP be in same subnet?
No. The service IP address and Boot IP address cannot be in same subnet. This is the basic requirement for HACMP cluster configuration. The verification process does not allow the IP addresses to be in same subnet and cluster will not start.

c. Can multiple Service IP addresses be configured on single Ethernet cards?
Yes. Using SMIT menu, it can be configured to have multiple Service IP addresses running on single Ethernet card. It only requires selecting same network name for specific Service IP addresses in SMIT menu.

d. What happens when a NIC having Service IP goes down?
When a NIC card running the Service IP address goes down, the HACMP detects the failure and fails over the service IP address to available standby NIC on same node or to another node in the cluster.

e. Can Multiple Oracle Database instances be configured on single node of HACMP cluster?
Yes. Multiple Database instances can be configured on single node of HACMP cluster. For this one needs to have separate Service IP addresses over which the listeners for every Oracle Database will run. Hence one can have separate Resource groups which will own each Oracle instance. This configuration will be useful if there is a failure of single Oracle Database instance on one node to be failed over to another node without disturbing other running Oracle instances.

f. Can HACMP be configured in Active - Passive configuration?
Yes. For Active - In Passive cluster configuration, do not configure any Service IP on the passive node. Also for all the resource groups on the Active node please specify the passive node as the next node in the priority to take over in the event of failure of active node.

g. Can file system mounted over NFS protocol be used for Disk Heartbeat?
No. The Volume mounted over NFS protocol is a file system for AIX, and since disk device is required for Enhanced concurrent capable volume group for disk heartbeat the NFS file system cannot be used for configuring the disk heartbeat. One needs to provide disk device to AIX hosts over FCP or iSCSI protocol.

h. Which are the HACMP log files available for troubleshooting?

Following are log files which can be used for troubleshooting:
1. /var/hacmp/clverify/current//* contains logs from current execution of cluster verification.
2. /var/hacmp/clverify/pass//* contains logs from the last time verification passed.
3. /var/hacmp/clverify/fail//* contains logs from the last time verification failed.
4. /tmp/hacmp.out file records the output generated by the event scripts of HACMP as they execute.
5. /tmp/clstmgr.debug file contains time-stamped messages generated by HACMP clstrmgrES activity.
6. /tmp/cspoc.log file contains messages generated by HACMP C-SPOC commands.
7. /usr/es/adm/cluster.log file is the main HACMP log file. HACMP error messages and messages about HACMP related events are appended to this log.
8. /var/adm/clavan.log file keeps track of when each application that is managed by HACMP is started or stopped and when the node stops on which an application is running.
9. /var/hacmp/clcomd/clcomd.log file contains messages generated by HACMP cluster communication daemon.
10. /var/ha/log/grpsvcs. file tracks the execution of internal activities of the grpsvcs daemon.
11. /var/ha/log/topsvcs. file tracks the execution of internal activities of the topsvcs daemon.
12. /var/ha/log/grpglsm file tracks the execution of internal activities of grpglsm daemon.

Frequently Asked Questions aix

Q1.How can u change IP of one node in HACMP environment ?

A- SMIT TCP/IP

Q2. How to fix if a external storage is visible to one node and not to other

node in

HACMP?

A- Using chdev command I will make PVID=yes and command is chdev -l

hdiskn -a PV=yes

Q3.How can u increase file system size in HACMP ?

A- Through C-SPOC

Q4.How to Fix if a VG is not Available in ODM?

A- smit importvg

Q5. What is heart beat in HACMP ?

A-heartbeat is used for health monitoring of nodes(whether or not nodes are

alive)

Q6.What is disk heart beat in HACMP ?

AQ

7.What are the basic requirement for two nodes to be configured in

HACMP?

A-each node should have two NICs, hardware should be

same(recommended) and OS and ML must be same

Q8.how to check whether a node is in cluster ?

A- using ./clstat

Q9.What is the daemon for HACMP?

A- clstrmgrES, clsmuxpdES,clinfoES and clcomdES

Q10.What are the permissions in AIX ?

A- read, write,execute ,SUID,SGID, Sticky bit

Q11.How to give all permission, only to user of a file ?

A- chmod 700 filename

Q12.How to set UID ?

A- chmod u+s filename

Q13.How to set GID?

A- chmod g+s filename or dir

Q14.How to create file system on new hard disk?

A- i)extendvg vgname hdiskn

ii) SMIT mklv, iii) SMIT crfs

Q15.How to increase file system size ?

A- chfs -a size=+no. of blocks /filesystem name

Q16.How to check which file system is available on which PV?

A- First check on which LV filesystem exists,say lv00, now use command lslv

-m lv00

Q17.What is command to list applied and committed software?

A- lslpp -l

Q18.By which command u can change applied state to committed state ?

A- installp -c -f software name

Q19.How to check ML level ?

A- oslevel -r

Q20.how to transfer boot image?

A- using bosboot command(eg. bosboot -a -d /dev/hdiskn)

Q21 how to replace faulty HDD ?

A-It depends on scenerio

Q22.how to check if a VG is mirrored?

A- lsvg -l vgname

Q23. How to check system configuration ?

A-prtconf

Q24.What is spooler ?.

A-a daemon

Q25 what is daemon for spooling ?

A- spooler

Q26.What is alog from where it takes info ?

A- command for seeing boot logs, takes info from var/adm/ras

Q27.Who command takes info fronm where ?

A- /etc/utmp

Q28.What are repository in ODM ?.

A- /etc/objrepos, /usr/lib/objrepos, /usr/share/lib/objrepos

Q29.how to list customized devices ?

A- lsdev -C -H

Q30.What is ODMGET ?

A- command to get information from ODM

I've replaced hdisk0 in a Blade server but I am having problems re-enabling

the mirror as it appears the configuration database is not recognizing the

new disk.

The first 2 steps to re-enable the mirror fail:

$ extendvg rootvg hdisk0

0516-008 extendvg: LVM system call returned an unknown

error code (-271).

0516-792 extendvg: Unable to extend volume group.

$ mirrorvg '-Q' '-m' rootvg hdisk0

0516-304 getlvodm: Unable to find device id

00000000000000000000000000000000 in the Device

Configuration Database.

0516-014 mirrorvg: []: The physical volume appears to belong to another

volume group.

0516-1200 mirrorvg: Failed to mirror the volume group.

I checked lspv and this showed the new disk as available:

$ lspv

hdisk0 none None

hdisk1 001016cc923411e7 rootvg active

However if I try to display the hdisk0 I get the following error:

$ lspv hdisk0

0516-304 : Unable to find device id hdisk0 in the Device

Configuration Database.

If I try to manually configure hdisk0 I get this message

$ cfgmgr -l hdisk0

cfgmgr: 0514-604 Cannot access the CuDv object class in the

Can anyone offer any suggestions as to what could be causing the problem?

chdev -l hdisk0 -a pv=yes

Q 1. Tell me about yourself?

Q 2. What is your current setup?

Q 3. What is NFS and which daemon it is using, what is configuration files?

Ans. NFS is network file system which use for sharing file on the linux/unix

plateform.

Server side daemons are- portmap, nfsd, rpc.mountd, rpc.statd,

rpc.lockd

Client side daemons are- portmap, biod, rpc.statd, rpc.lockd

Q 4. What is portmap?

Ans. It provide port no for client request

Q 5. How to increase filesystem size?

Ans. Chfs –a size= +m,g /filesystem

Q 6. What is difference between RAID 0 and RAID 1?

Ans Raid 0 is used for striping purpose and Raid 1 is using for mirroring.

Q 7. What is swapon and swapoff commend?

Ans Swapon turn on paging space and swapoff used to turnoff paging page

Q 8. What is mksysb?

Ans It’s a command which used to take backup of rootvg

Q 9. What is difference between jfs and jfs2?

Ans There are following difference-------

jfs jfs2

1-Inode size 128 Byte 512Byte

2-Max file size 64GB 4PB

3-Max filesystem size 1TB 4PB

4-Cmpresion yes

no

5-jfslog-type General jfslog inlinejfslog

Minimum file system size not specify 16MB

Inode allocation static dynamic

10. How to start mountd daemon?

Ans startsrc –s mountd

Q what is path?

Q1. Which is the ODM command to list the ODM object that stores the

physical volume identifier? [1 mark]

Ans. odmget -q name=hdisk0 CuAt

Q2. What are the basic components of ODM and in which format data is

stored in ODM. [2 marks]

Ans. Components are uniquetype, attribute, deflt and values

Data is stored in binary format

Q3. Which is the environment variable used by all the ODM commands

And that is set in file /etc/environment. What is its default value. [2 marks]

Ans. ODMDIR and default value is /etc/objrepos

Q4. Which three types of information are not managed by ODM? [1/1/2]

Ans. Filesystem information, User/Security information, Queues and Queue

devices.

Q5. Which repositories stores the ODM object classes? [1/1/2]

Ans. /etc/objrepos, /usr/lib/objrepos and /usr/share/lib/objrepos

Q6. Which is the ODM object class used by cfgmgr to determine the correct

sequence when configuring devices. [1/2 mark]

Ans. Config_Rules

Q7. What are the contents of Boot Logical Volume? Briefly explain them? [2

marks]

Ans. AIX Kernel, rc.boot, Reduced ODM and Boot commands.

AIX kernel – It is always loaded from the boot logical volume. It provides

basic services like process, memory and device management.

Rc.boot – after starting the kernel, the boot script rc.boot gets control over

the boot process.

Reduced copy of ODM – During the boot process many devices are

configured before hd4 is available. For these devices the corresponding ODM

files must be stored in the boot logical volume.

Boot commands – The boot commands are programs that are called during

the boot process eg. Bootinfo, cfgmgr.

Q8. How to fix a corrupted BLV by using a CD or tape? [2 marks]

Ans. 1. Boot the machine in maintenance mode from a CD or tape.

2. Access rootvg.

3. Run command bosboot –ad /dev/hdiskn

4. Use command Shutdown –Fr so that all changes are written from

memory to disk.

Q9. List the sequence in which the default boot list in RS/6000 is stored? [2

marks]

Ans. 1. Diskette Drive

2. CD-ROM

3. Internal disk

4. Communication adapter (like Ethernet or token-ring)

Q10. The diag command is part of which package?

Ans. bos.rte.diag [1/2 mark]

Q1.How can u change IP of one node in HACMP environment ?

A- SMIT TCP/IP

Q2. How to fix if a external storage is visible to one node and not to other

node in HACMP?

A- Using chdev command I will make PVID=yes and command is chdev -l

hdiskn -a PV=yes

Q3.How can u increase file system size in HACMP ?

A- Through C-SPOC

Q4.How to Fix if a VG is not Available in ODM?

A- smit importvg

Q5. What is heart beat in HACMP ?

A-heartbeat is used for health monitoring of nodes(whether or not nodes are

alive)

Q6.What is disk heart beat in HACMP ?

AQ

7.What are the basic requirement for two nodes to be configured in

HACMP?

A-each node should have two NICs, hardware should be

same(recommended) and OS and ML must be same

Q8.how to check whether a node is in cluster ?

A- using ./clstat

Q9.What is the daemon for HACMP?

A- clstrmgrES, clsmuxpdES,clinfoES and clcomdES

Q10.What are the permissions in AIX ?

A- read, write,execute ,SUID,SGID, Sticky bit

Q11.How to give all permission, only to user of a file ?

A- chmod 700 filename

Q12.How to set UID ?

A- chmod u+s filename

Q13.How to set GID?

A- chmod g+s filename or dir

Q14.How to create file system on new hard disk?

A- i)extendvg vgname hdiskn

ii) SMIT mklv, iii) SMIT crfs

Q15.How to increase file system size ?

A- chfs -a size=+no. of blocks /filesystem name

Q16.How to check which file system is available on which PV?

A- First check on which LV filesystem exists,say lv00, now use command lslv

-m lv00

Q17.What is command to list applied and committed software?

A- lslpp -l

Q18.By which command u can change applied state to committed state ?

A- installp -c -f software name

Q19.How to check ML level ?

A- oslevel -r

Q20.how to transfer boot image?

A- using bosboot command(eg. bosboot -a -d /dev/hdiskn)

Q21 how to replace faulty HDD ?

A-It depends on scenerio

Q22.how to check if a VG is mirrored?

A- lsvg -l vgname

Q23. How to check system configuration ?

A-prtconf

Q24.What is spooler ?.

A-a daemon

Q25 what is daemon for spooling ?

A- spooler

Q26.What is alog from where it takes info ?

A- command for seeing boot logs, takes info from var/adm/ras

Q27.Who command takes info fronm where ?

A- /etc/utmp

Q28.What are repository in ODM ?.

A- /etc/objrepos, /usr/lib/objrepos, /usr/share/lib/objrepos

Q29.how to list customized devices ?

A- lsdev -C -H

Q30.What is ODMGET ?

A- command to get information from ODM

Q.1 How will you change bootlist for PCI & classical system (MCA) ?

Ans. # bootlist -m normal hdisk1 hdisk0

On some PCI systems (like 43p) bootlist cannot be changed using the

bootlist command. For such systems , we have to change the bootlist

using System Management Services (SMS) menu by pressing F5/F6 key

at the time of system boot.

Q.2 How do you start & stop a subsystem & susbsystem group like inetd

and tcpip.

Ans. # startsrc -g tcpip --> for starting a group of services

# startsrc -s inetd --> for starting a single service.

Q.3 What are the packages to be installed for man pages & networking?

Ans. bos.info and bos.net

Q.4 How do you remove an installed package?

Ans. # installp –u –f listfile

Q.5 What is the use of mkszfile?

Ans. Saves the system state for reinstallation on the current system or

another system. The mkszfile command overwrites an existing

/image.data file with new information.

Q.6 Write down the command for checking bootlog?

Ans. # alog -o -t boot

Q.7 How do you change the run level form single user mode to multiuser

mode?

Ans. # telinit 2

Q.8 Write down the command syntax for listing all supported and

customized devices?

Ans. $ lsdev -C –H --> lists all customized devices with header

$ lsdev -P –H --> lists all supported devices.

Q9. Write the command for checking the amount of memory for PCI and

CLASSICAL RS6000?

Ans. $ lsattr -E -l mem0 , lsattr –El Sys0 –a realmem

Q.10 Write the command for changing maximum number of user process

from 40 to 80?

Ans. # chdev -l sys0 -a maxuproc=80

Q.11 How do you configure a defined device?

Ans. # mkdev -l devname

Q.12 Write down the command for disabling tty0?

Ans. # chdev –l ‘tty0’ –a login=’disable’

Q.13 Can one printer belongs to multiple queues? If yes then when do you

use this and if no why it's not possible?

Ans. Yes .

We use this when the same printer is used under different emulation

like – post script , PCL emulation ,ASCII , etc. We can add different queues

for different emulation.

Q.14 Can you configure a queue to multiple printers (y/n)?If yes then write

the print command to a queue on a specific printer? If no write down the

reason.

Ans. Yes

$ lpr –P lp0:

Q.15 What is the command syntax for testing queue status?

Ans. $ lpstat –t

Q.16 Where does the information about queues and printer stored?

Ans. /etc/qconfig

Q.17 Write down the command syntax for changing the priorities of a print

job?

Ans. # qpri - # JobNumber -a PriorityNumber

The job number and priority number can be obtained by running the

lpstat –t command. The priority can only be changed by printer

administrator or system administrator.

Q.18 Write down commands syntax for listing all VG and content of a single

vg?

Ans. $ lsvg --> lists all volume groups.

$ lsvg –o --> lists only active volume groups.

$ lsvg --> displays characteristics of volume

group.

$ lsvg –l --> logical volumes

$ lsvg –p --> physical volumes

Q.19 Write down the command to find out which PV belongs to which VG?

Ans. $ lspv

Q.20 Write down command for making a volume group ?

Ans. # mkvg –y Physical volume names

-B flag may be used for creating big volume group ( maxpvs. 128)

-t is used for specifying the PP size.

Q.21 What is the command for synchronizing a logical volume copy

(mirror)?

Ans. # syncvg

name could be volume group name , physical volume name or logical

volume name.

Q.22 Write down the command for turning off a mirroring of a logical

volume ?

Ans. # rmlvcopy

Q.23 Can you define different Quotas on different filesystems for a single

user?

Ans. Yes.

Q.1 How to go to parent directory ?

Ans. $ cd ..

Q.2. How to execute .profile without logging in again ?

Ans. $ sh .profile

Q.3. How to debug shell script ?

Ans. $ sh -x shellfile.

Q. 4. What is first line in shell script

Ans. #!/usr/bin/ksh - path to the shell but no comments. ! is

important.

Q. 5. If you are not able to telnet what are the possible reasons and how to

diagnose it ?

Ans. The possible reasons are:

1. Network connection not through.

2. Wrong IP address.

3. Client not in the same network.

4. Telnet disabled on the server.

The problem could be diagnosed using 1.) ping 2.) ifconfig 3.) netstat –v

4.) traceroute

Q.6. What is the entry in resolv.conf for DNS client ?.

Ans. domain domain.com

nameserver IP.ADDRESS.OF.SERVER

nameserver IP.ADDRESS.OF.SECONDARY

Q.7. How to extend lv ?

Ans. # extendlv

Q.8. What is echo $$ ?

Ans. Returns current shell’s PID

Q.9. How to unmount a filesystem and if it is not able to unmount what are

the steps ?

Ans. # umount

Q.10. How to take the backup of a dump?

Ans. # snap -a -o

-a Gathers all system configuration information. This option requires

approximately 8MB of temporary disk space.

-o OutputDevice Copies the compressed image onto diskette or tape.

Q.11. How to extend the File systems size ?

Ans. # chfs -a size=Newsize filesystem

-a size=NewSize Specifies the size of the Enhanced Journaled File

System in 512-byte blocks. If Value begins with a +, it is interpreted as a

request to increase the file system size by the specified amount.

Q.12. How to see the routing table ?

Ans. $ netstat –rn

-n Shows network addresses as numbers.

-r Shows the routing tables

Q.13. How to see the arp cache ?

Ans. $ arp -a

Q.14. What are the daemons for NFS Primary server ?

Ans. nfsd, rpc.statd, rpc.lockd, portmap

Q.15. What are the daemons for NIS ?

Ans. ypbind, ypserv, yppasswd, portmap

Q.16. How to access the NFS mounted File System ?

Ans. Just go to the Directory or Access the directory under the filesystem

.17. What is automount ? ( explain briefly )

Ans. a) Used for automatic and transparent mounting and unmounting of

NFS File systems.

b) Based on AutoFS facility.

c) Uses automounter map files to find the mount directories and mount

arguments. Map can be text files or NIS maps.

d) automount command

e) automountd daemon

f) Client-side server

Benefits:

a) Reduces system administration of /etc/filesystems file particularly if

NIS maps are used

b) No pre-mounting of directories not currently needed thus reducing

possibility of client hang due to down server

c) Distributes client workload for NFS read-only file systems

d) Provides method for single-system image for clients

Q.18. How to copy a LV ?

Ans. # cplv [ -v VolumeGroup ] [ -y NewLogicalVolume ]

SourceLogicalVolume

Q.19. How to see the active VG ?

Ans. $ vg –o

Q.20. How to see the all the LVs in all active VGs ?

Ans. $ lsvg -o | lsvg -i –l

Q.21. Where the System Log files are located ?

Ans. /var/adm/ras

Q.22. How to see the paging space ?

Ans. $ lsps -a

Q.23. How to see the System Dump Space ?

Ans. $ sysdumpdev -l

-l Lists the current value of the primary and secondary dump devices,

copy directory, and forcecopy attribute.

Q.24. How to see memory activity ?

Ans. Using "sar", "vmstat"

Q.25. How to install software ?

Ans. # installp –a –Q –d -f ‘all latest’

-a Applies one or more software products or updates.

-d Device Specifies where the installation media can be found.

-f ListFile Reads the names of the software products from ListFile.

Q.26. "no" command options especially 'thewall' parameter.

Ans. Network option Configures network attributes.

no { -a | -d Attribute | -o Attribute [ =NewValue ] }

thewall Specifies the maximum amount of memory, in kilobytes, that is

allocated to the memory pool. In AIX 4.2.1 and earlier, the default value is

1/8 of real memory or 65536 (64 megabytes), whichever is smaller. In AIX

4.3, the default value is 1/8 of real memory or 131072 (128 megabytes),

whichever is smaller. In AIX 4.3.1, the default value is 1/2 of real memory

or 131072 (128 megabytes), whichever is smaller. In AIX 4.3.2 and later,

the default value depends on whether you are running on a CHRP machine

or not. For non-CHRP machines, the default value is 1/2 of real memory or

262144 (256 megabytes), whichever is smaller. For CHRP machines, the

default value is 1/2 of real memory or 1048576 (1 gigabyte). thewall is a

runtime attribute.

Q.27. ODM - where it resides, how to modify,list,etc.,

Ans. ODM resides in /etc/objrepos , /usr/lib/objrepos and

/usr/share/lib/objrepos.

To modify ODM use the following sequence :

# odmget -q"uniquetype=tape/scsi/8mm and attribute=block_size"

PdAt > file

# vi file edit the corresponding attribute.

# odmdelete -o PdAt -q"uniquetype=tape/scsi/8mm and

attribute=block_size"

# odmadd file

To list contents of ODM use lsdev command.

Q.28. File systems - nbpi, etc., read the theory.

Ans. nbpi – number of bytes per inode.

This feature of filesystem is used when fragmentation of files are set.

If a filesystem contains small files , then it is advantageous to keep the

fragment size small , so that space is not wasted. Normally there is one

inode created for every possible file in a filesystem. However in actual

practice the number of inodes required are quite less. Therefore to save on

space allocated for inodes , we specify the nbpi value.

Q.29. What is SPOT? Or Explain SPOT ? Is it part of NIM ?

Ans. The SPOT contains the directory structure for an installed /usr file

system. It also contains subdirectories for the "root" parts of installed

filesets. Since the SPOT contains both usr and root files, software

maintenance must be performed on the SPOT in order to update the

software that is running on the clients. Such actions must be performed

using the NIM cust and maint operations.

Spot is used by the client during NIM install or boot. The following

operations are performed to manage the software for diskless and dataless

clients:

1. The /usr files are installed in the SPOT. These files are automatically

seen by all the clients that mount the SPOT as their /usr file systems.

2. The root files are installed in special subdirectories in the SPOT.

3. After all the filesets have been installed in the SPOT, the root files are

copied to the directories of any diskless or dataless clients that have

been initialized with the SPOT

Q.30 How to replace an ssa disk ? ( Refer Problem solving guide-redbook)

Q.31. How to configure raid 5 and hot spare

Q.32. How do I setup anonymous ftp on my AIX system?

Ans. /usr/lpp/tcpip/samples/anon.ftp It is a shell script and will set up a

anonymous ftp site on your local RS/6000.

Q.33 How can I share files/printers with Windows 95?

Ans. The freeware solution is Samba .Commercial solutions include

Fusion95 from Performance Technology

Q.34. How do I shrink /usr?

Ans. 1) Remove any unneeded files from /usr.

2) Make sure all filesystems in the root volume group are mounted. If

not, they will not be included in the re-installed system.

3) Type mkszfile. This will create /image.data that contains a list of

the active filesystems in the root volume group that will be included in the

installation procedure.

4) Edit /image.data. Change the size of /usr to what you want.

IMPORTANT: Make sure that you DO NOT enter a value which is less

than the size of the filesystem required to contain the current data. Doing so

will cause the re-installation procedure to fail.

5) chdev -l rmt0 -a block=512 -T

6) Unmount all filesystems that are NOT in the root volume group.

7) Varyoff all user-defined volume groups, if any

# varyoffvg VGname

8) Export the user-defined volume groups, if any

# exportvg VGname

9) With a tape in the tape drive, type

# mksysb /dev/rmt0

This will do a complete system backup, which will include information (in

the /image.data file) for the installation procedure on how large the

filesystems are to be created.

10) Install the backup .

11) When the installation is complete, you may then import any userdefined

volume groups.

# importvg -y VGname PVname

where "VGname" is the name of the volume group, and "PVname" is the

name of any one of the physical volumes in the volume group.

12) Varyon your user-defined volume groups

# varyonvg VGname

The reduction of the filesystems is now complete.

Q.35 What is LVCB ?

Ans. The logical volume control block (lvcb) is the first 512 bytes of a

logical volume. This area holds important information such as the creation

date of the logical volume,

information about mirrored copies, and possible mount points in a journaled

filesystem.

Q.36. What is the limit on Physical Partitions Per Volume Group?

Ans. 1016 Physical Partitions Per Disk in a Volume Group

In most cases, not all the possible 1016 tracking partitions are used

by a disk.

The default size of each Physical Partition during a "mkvg" command is 4

MB, which implies that individual disks up to 4 GB can be included into a

volume group.

If a disk larger than 4 GB is added to a volume group (based on usage of

the default 4 MB size for Physical Partition) the disk addition will fail with a

warning message that the Physical Partition size needs to be increased.*

There are two instances where this limitation will be enforced. The first case

is when the user tries to use "mkvg" to create a volume group where the

number of physical partitions on one of the disks in

the volume group would exceed 1016. In this case, the user must pick from

the available Physical Partition ranges of:

1, 2, (4), 8, 16, 32, 64, 128, 256, 512 or 1024

Megabytes and use the "-s" option to "mkvg". The second case is where the

disk which violates the 1016 limitation is attempting to join a pre-existing

volume group with

the "extendvg" command. The user can either recreate the volume group

with a larger Physical Partition size (which will allow the new disk to work

with the 1016 limitation)

or the user can create a standalone volume group (consisting of a larger

Physical Partition size) for the new disk.

Q.37. Why am I having trouble adding another disk to my VG?

Ans. a.) Not enough space left in the volume group descriptor area.(VGDA)

b.) Volume group can have a maximum of 32 disks in a volume group.

( 128 for big VG)

Q 38. What are the limits on a file, filesystem?

File jfs-Filesystem

3.2.5 2 GB 2 GB

4.1.x 2 GB 1 TB

4.2 64GB 1 TB

4.3 64 GB 1 TB

5.x 1 Tb 4 PT

Q.39 How do I fix Volume Group Locked?

Ans. Use

# (putlvodm -K `getlvodm -v `)

Q.40. How do I remove a volume group with no disks?

Ans. # exportvg

Q.41 How do I get rid of a disk that is no longer really in the volume group?

Ans. # reducevg -d -f

or if the hdname can't be found:

# reducevg -d -f

Q.42 What are the theoritical limits within the LVM?

Ans. The system may have 1 to 255 Volumes Groups (VG's).

Each VG may contain 1 to 32 Physical Volumes (PV's).

Each PV may contain upto 1016 Physical Partitions (PP's).

Each PP may have a size (square of 2) from 1 to 256MB (1024MB for

AIX 4.3).

The filesystem and file limits are :

File jfs-Filesystem

3.2.5 2 GB 2 GB

4.1.x 2 GB 1 TB

4.2 64GB 1 TB

4.3 64 GB 1 TB

5.x 1 Tb 4 PT

Q.43. How do I control how hostnames are resolved?

Ans. The default order can be overwritten by creating the configuration file,

/etc/netsvc.conf and specifying the desired order. Both the default and

/etc/netsvc.conf can be overwritten with the environment variable,

NSORDER.

Q.44 dtlogin ignores .profile?

Ans. Edit .dtprofile and remove # from the last line containing

DTSOURCEPROFILE=true.

Q.45. How do I transfer files between AIX and DOS disks?

Ans. Install the AIX package bos.dosutils which has commands for

transferring files between DOS diskettes and AIX. The commands are

dosread, doswrite, dosdir, dosdel,

and dosformat.

Q.46. How do I determine the clock frequency of a RS/6000 by software ?

Ans. There is no way to find out the clock frequency with a piece of

software

VERY IMPORTANT

Q1. What are your daily activities?

Ans. My daily activities include the following tasks:

1. To backup mksysb.

2. To work on LVM e.g. File system management.

3. To apply patches using instfix and emgr commands.

4. To manage daemons (Whether the daemons are working or not. If not

working then to restart those daemons.). I get to know about these through

Incident Management tickets.

5. Performance Monitoring using common AIX tools like sar, vmstat and

iostat and ps.

6. Looking at errors using errpt command.

7. Creating LPARs, though its not very occasional activity.

8. Dynamic resource management among LPARs using DLPAR.

9. Client installation using NIM.

2. How AIX is different from other Unix Operating systems ..?

Ans : a..) LV M Concepts ( Policies …where you can optimize the

performance )

b) ODM

c) Dynamic Kernel

d) Auto Configuration of devices (cfgmgr)

e) Dynamic increasing of file system

f) JFS & JFS Log..Prevents the file system corruption.

g) Booting from alternate Disk

h) Rootvg Cloning

3. How to install oracle on linux? What are the prerequisites to

install oracle ?

Ans : Need to set kernel parameters, install necessary fixes, create required

users and groups, set path and profile, exact installation procedure comes

documented with oracle installation media.

. How to u find the system is I/O bound

Ans : If the iowait value is more in the iostat output system can say I/O

bound provided the disk balance are good.

5. How u find system is memory bond?

Ans : Buy observing the pi&po field in vmstat o/p.

6. How to see user resource limit

Ans : ulimit –a

7. Boot Process of AIX?

Ans : Post

Locate the blv using bootlist

Load the blv and pass control

Configure the device through cfgmgr

Start init and process /etc/inittab

8. How to recreate BLV?

Ans :Got on SMS mode – access rootvg with mounting then #bosbot –ad

/dev/hdisk0 #shutdown –Fr

9.How to change the maintenance mode?

Ans : Init m

10.How to reset lost password of root?

Ans : Got ot SMS mode – access rootvg with mounting then #passwd then

#shutdown –Fr

Device

What is the stage of cfgmgr?

Ans : Check predefined database.

Load device driver from odm and made entry on /dev directory

Put the entry in customized devices database.

Q.10 Write the command for changing maximum number of user

process from 40 to 80?

Ans. # chdev -l sys0 -a maxuproc=80

Q.11 How do you configure a defined device?

Ans. # mkdev -l devname

Q.12 Write down the command for disabling tty0?

Ans. # chdev –l ‘tty0’ –a login=’disable’

5. How to make available disk to PV.

Ans: #chdev -l hdisk1 - a pv=yes

16. How to use chdev ..command … to change the block size of

tape

Ans : chdev -l rmt0 block_size=1024

17. How to see the default attributes of tape or system

Ans : 1.) lsattr -E -l rmt0 -D

2.) lsattr -E -l sys0 -D

18. How to remove & delete the device(tape) information from

database.

Ans : 1.)rmdev -l rmt0 -d

19. How to make defined device(tape) to available .

Ans : 1.)mkdev -l rmt0

20. How to see the real memory of the system ?

Ans : 1.)lsdev -Cc memory or

2.) lsattr -E -l mem0

21.how to check lun information of SAN enviroment in AIX

Ans : using lsdev

22. How to see the firmware

Ans : lsattr –el sys –a fwver

Filesystem

3. Lists out the Advantage of Having LVM .

1. Optimizing the LV for maximum performance

2. Increasing the filesystem size dynamically

3. Mirroring of LVs

4. Striping of logical volumes

4. What is the limitation of LVM ?

1. Maximum VGs per system is 255

2. Maximum PVs per VG is 32

3. Maximum LVs per VG is 256

4. Maximum PPs per PV is 1016 ( AIX 4.3 supports multiple numbers )

5. Striped logical volume can not be mirrored

6. Moving data acrross VG is not possible

7. Reducing the size of LV is not possible.

What is superblock

The first block on any file system that contain metadata of its like no of

inode and free inode etc.

6. How to restricts the VG spaning on numbers of PVs? Is there any

smit is available?

With mkvg command you have to use -d flag to limit the VG spanning

across more disks

There is not smit available.

7. How to restricts I/O operation on particular PV?

# chpv -v r pvname

8. What is the Command used to migrate the PV & LV? Is it possible

to migrate the PV between VGs if not possible, how to copy the

LVs from one VG PV to other VG PVs.

1.) #migratepv

2.) It’s not possible

3.) calve

9.How will you create filesystem?

A. crfs -v fstype -g volgroup -m mountpt -p permission -a size

10.How will you convert normal vg to big vg.

A. chvg -B vgname

8.What is the use of synvg and synclvodm

A. syncvg:to update mirrored lv copy in a vg

synlvodm:Synchronizes or rebuilds the logical volume control block,

the device configuration database, and the volume group descriptor areas

on the physical volumes.

4.How many lvs will be created at the time of AIX installation?

A./dev/hd1 - /home, /dev/hd2- /usr, /dev/hd3-/tmp, /dev/hd4-/, /dev/hd5

- /boot,/dev/hd6 - paging, /dev/hd8 - /jfslog, /dev/hd9- /var,/dev/hd10 -

/opt

5.What is use of /dev/hd7?

A. Not used

6-What is the difference between jfs & jfs2 ?

A. There are following difference-------

jfs jfs2

1-Inode size 128 Byte 512Byte

2-Max file size 64GB 4PB

3-Max filesystem size 1TB 4PB

4-Cmpresion yes no

5-jfslog-type General jfslog inline-jfslog

Minimum file system size not specify 16MB

Inode allocation static dynamic

7-What is inode?

A. This is indexnode containing the information about the file like filename,

filesize, fileowner, filegroup, access date& time, Modification date & time etc.

8-How many pvs possible in Big VG & Scalable VG?

A. This is 128 & 1024

9-How will you define the VG?

A. # mkvg -s pp_size -t t-factor -y vg_name hsidkx

10.How will you change the normal VG to Big VG?

A. #chvg -B vg_name

11-What is t-factor?

A. This is the factor used for define the no.of PP,s in a PV within the VG,if

we are putting the value of t-factor 2 it will extend the max no of pp,s

per PV and reduced the max no of PV,s within the VG

13- How many max LV possible in a scalable VG?

A. These are 4096 per VG

Q33.What is the use of lvlstmajor command?

Ans- To knows the free Major Number.

Q34.How to increase the filesystem size, can we reduce the fs size?

Ans- #chfs -a size=+value /fsname, fs size can be reduce in Aix5.3 not in

Aix 5.1

How will you move pp to particular disk?

Migratelp Lvname/lp no [/ copy no] Destpv[/ppartno

To move the first logical partitions of logical volumelv00 to hdisk

Migrate lv00/1 hdisk1

Q35.How to create LV?

Ans-#mklv -t lvtype -y lvname vgname no.of Lps pvname

t- for type it may be jfs,pagingspace,journallog,boot type.

Q36. How to replace the mirror disk from rootvg?

Ans-#unmirrorvg rootvg pvname

#sysdumpdev -p /dev/sysdumpnull

#reducevg rootvg pvname

#rmdev -l hdiskx -d

if mirror disk is bootable put #chpv -c hdiskx

Now remove faulty disk and put new one then run #cfgmgr

#extendvg rootvg hdisky

#mirrorvg -S rootvg hdisky

#bosboot -ad /dev/hdisky

#bootlist -m normal hdisky

Q37. What is Quorum?

Ans-This is the voting of VGDA,used to recover the data after a disk crash!

,if VGDA area is >51% ,then only the quorum will come in picture. Quorm is

provide datat intrigrity, data redundancy from in mirrorvg.

17. If I have 4 CPUs and 2GB RAM and 2 Hard Disks, can I create 8

Partions?

19. How to migrate filesystem from one hard disk to another hard disk?

22. How to Configure SAN disk in Aix? How will you distinguish between

normal disk and SAN disk?

3. How would you increase(Manage) the Filesystem size?

Ans. This depends upon the name of the filesystem. If its /usr then normally

we have to increase the filesystem, because we don't have chances of

compressing the files. In case of other filesystems like /var, we compress

the old log files. Some times we inspect the data which is not required, we

delete that after taking the backups and consulting the appropriate persons.

In case we have to increase the Filesystem size then we follow the

procedure as:

To check the no. of free PPs in filesystems using "lsvg -p" command and the

size of the PP in CG. Then we increase the filesystem size by:

chfs -a size=+NewSize(M\G\or 512 Bytes multiple) Name_of_FS

If the no. of free PPs is insufficient then we have to add new harddisk,

extend

the VG and then run the chfs command again.

Q.21 What is the command for synchronizing a logical volume copy

(mirror)?

Ans. # syncvg

name could be volume group name , physical volume name or logical

volume name.

Q.22 Write down the command for turning off a mirroring of a

logical volume ?

Ans. # rmlvcopy

Q.18. How to copy a LV ?

Ans. # cplv [ -v VolumeGroup ] [ -y NewLogicalVolume ]

SourceLogicalVolume

Q.41 How do I get rid of a disk that is no longer really in the volume group?

Ans. # reducevg -d -f

or if the hdname can't be found:

# reducevg -d -f

Q.23 Can you define different Quotas on different filesystems for a

single user?

Ans. Yes.

Q.35 What is LVCB ?

Ans. The logical volume control block (lvcb) is the first 512 bytes of a

logical volume. This area holds important information such as the creation

date of the logical volume,

information about mirrored copies, and possible mount points in a journaled

filesystem.

Q.28. File systems - nbpi, etc., read the theory.

Ans. nbpi – number of bytes per inode.

This feature of filesystem is used when fragmentation of files are set.

If a filesystem contains small files , then it is advantageous to keep the

fragment size small , so that space is not wasted. Normally there is one

inode created for every possible file in a filesystem. However in actual

practice the number of inodes required are quite less. Therefore to save on

space allocated for inodes , we specify the nbpi value.

Q.37. Why am I having trouble adding another disk to my VG?

Ans. a.) Not enough space left in the volume group descriptor area.(VGDA)

b.) Volume group can have a maximum of 32 disks in a volume group.

( 128 for big VG)

Difference between fsck –y and fsck –f

Ans : fsck –f: perform the fast check. It will not check that filesystem were

umounted successfully.

FSCK –y : assumes a yes response to all questions asked by the fsck

command

What are the 6 steps in fsck –y

1. Check Block and size

2. Check pathname

3. Check connectivity

4. Check reference counts

5. Check inode map

6. Check block map

How to create file system in raw hard disk?

Extendvg, mklv, crfs

What are the stanza in /etc/filesystem?

Dev=

Mount=

Log=

Vfs=

Check=

Type=

What is proc file system?

Contain info about all currently running process

calculation of pp

pv size = 80GB (81920 MB)

default no of pp = 1016

pp size = h/d in mb / default no of pp (81920/1016) = 80mb (>64) that’s

why 128 mb

if we want to increase no of pp = t factor increase

no of pp = default no of pp * t factor ( 1016*2 = 2032 pp)

according that if we want to decrease size of PP then we have to increase t

factor mean no of pp

ppsize now = 81920/2032 = 40mb means >32 that’s why it’s a 64 mb

6+

How you will maintain the password polices?

Using chuser and /etc/security/user

What is journaled file system?

It maintains a log in corresponding log device before committing any

changes to LV and thus maintains integrity of file system.

Boot & dump * Error & ODM

Q.24. How to see memory activity ?

Ans. Using "sar", "vmstat"

What is difference between tar and cpio?

Ans : Tar handle symbolic link. cpio doesn’t.

What will do when odm in non-rootvg corrupted? (Rename vg also)

Ans :Exportvg and importvg

Why quorum is disabled in mirroring.

Ans : If it is mirrored within two pv VGDA ill be three, one ill have two

VGDA means 66%, another ill have one VGDA means 33% , we can`t

activate which failed with in 51% VGDA.. that’s what quorum is disabled in

two mirrored condition.

Will file system extend or reduce update the vgda?

Ans : Yes as the use of pp is maintained by the vgda

Q.25. How to install software ?

Ans. # installp –a –Q –d -f ‘all latest’

-a Applies one or more software products or updates.

-d Device Specifies where the installation media can be found.

-f ListFile Reads the names of the software products from ListFile.

Q.3 What are the packages to be installed for man pages &

networking?

Ans. bos.info and bos.net

Q.4 How do you remove an installed package?

Ans. # installp –u –f listfile

Q.5 What is the use of mkszfile?

Ans. Saves the system state for reinstallation on the current system or

another system. The mkszfile command overwrites an existing

/image.data file with new information.

Q.6 Write down the command for checking bootlog?

Ans. # alog -o -t boot

Q.10. How to take the backup of a dump?

Ans. # snap -a -o

Q.8. What is echo $$ ?

Ans. Returns current shell’s PID

Q.3. How to debug shell script ?

Ans. $ sh -x shellfile.

Q.3 What are the packages to be installed for man pages &

networking?

Ans. bos.info and bos.net

Q.4 How do you remove an installed package?

Ans. # installp –u –f listfile

Q.5 What is the use of mkszfile?

Ans. Saves the system state for reinstallation on the current system or

another system.The mkszfile command overwrites an existing

/image.data file with new information.

17.How will you delete an entry from ODM?

Ans : #odmdelete

Q3.What is the component of BLV?

Ans- These are Reduce ODM, RAMfs, Aix Kernel, Aix Commands

Q4.How to Recover BLV if corrupted, which LED will Glow for that?

Ans-Boot the system by Cd or tape in Maintenance mode and access the

rootvg then run #bosboot -ad /dev/hdiskx command set set the bootlist and

restart the system. LED 557 will glow.

Q5.What is reduce ODM?

Ans-This is the copy of ODM which is required for Configure the base

devices.

Q6.What is default dump device?

Ans : #/dev/hd6

Q7.How to set bootlist?

Ans : #bootlist -m normal/service device name priority wise

Q8.How to see boot device?

Ans : #bootinfo -b

Q9.What is SMS Mode?

Ans-This is System management service mode use for change the

bootlist,see the configuration etc.

Q10.What is errpt?

Ans-This is a command used to display the error details of system. It reads

the /var/adm/ras/errorlog file.

Q11.What is sticky bit & How to identify it?

Ans-This is the permission given to a directly so that the user can create the

file but can not remove the file of other users. It will show a "t" with

execute permission

Q15.What is the default run level in Aix? How would you see it?

Ans-This is 2 #who –r

Q17.How to know the Aix version?

Ans-#oslevel –r

95. How to inittiate system dump ?

Ans : # sysdumpstart -p (for primay )

# sysdumpstart -s (secondary)

96. What is SNAP command does.

Ans : Snap is a general purpose commnad use to gather the information

about system

9. What is the command used to see the platform type of your

system & what are the different type of platforms available .

Ans : 1.) bootinfo -p and oslevel to see the version.

2.) rs6k,rspc & chrp

11. What are different types of installation methods available ?

what is different

Ans 1.)New & complete overwrite

2.) Preservation

3.) Migration installation.

12. What is dynamic kernel ? explain with example

Ans : The devices or some paramters if you are adding or deleting from the

systems its not required to reboot.

Ie ..Kernel is updated dynamically.

Say ..example if you change the IPADDRESS , its not required to reboot

the system .

Q.44 dtlogin ignores .profile?

Ans. Edit .dtprofile and remove # from the last line containing

DTSOURCEPROFILE=true.

66. What is purpose of /etc/nologin , /etc/exclude.rootvg

,/etc/preserve.list .

Ans : /etc/nologin - it does not allows new users to login.

/etc/exclude.root - list of filesystesms , directories or files , does not get

backedup during the system backup.(mksysb)

/etc/preserv.list - list of filesystems or files to be preserved during the

preservation installation.

67. How to list the particular user attributes.

Ans : # lsuser -f user name

68. What is purpose of usrck ,pwdck & grpck.

Ans : # usrck -t user name checks the discripances on users information.

# pwd - checks password file for user discripancies.

# grpchk - checks the group informations

69. What is the purpose of ADMCHG flag in /etc/security/password

file.

Ans:It will ask user to change the first time password.

70. What is the file used to limit the access time of particular user.

Ans :/etc/security/login..cfg

71. How to see how long system has been working .

Ans : uptime

72. Where the SU log activity is stored.

Ans : Var/adm/sulog

73. Where the failed login information is stored.

Ans : /etc/security/failedlogin

74. What is diffrence between /etc/objerepos,/usr/lib/objrepos&

/usr/share/objrepos.

Ans :/etc/objrepos -stores the ODM objects of that systems.

/usr/lib/objrepos -stores the ODM objects ..that can be shared by other

AIX systems.

/usr/shared/objrepos -contains information , that can be used by other

unix systems

75. What are the commands used to manipulate the ODM.

Ans :#odmget , odmadd , odmdelete,odmdrop ,odchange,odmcreate &

odmshow

76. What is flashing 888.

Ans :1. It may be H/W or system dump

77. What is 0c0 .

Ans : Successful complition of dump

78. How to find out the FRU number & micro code level (ROS or EC

level) device.

Ans : #lscfg -vpl device name

lscfg -vpl hdisk0

79. What is ram file system?

Ans : File system resides on system memory …usually on system booting..

80. What is purpose of TMOUT Variables? Where its specified.

Ans : With help of TMOUT variable if the shell process is not active for period

specify by the time out variable the process will be automatically

terminated..

/etc/profile

81. What is advantage of Rsh (restricted ).

Ans :The following are not allowed.

1.) cd 2) ./ 3)changing path variable 4 ) Redirect output >

or >>

82. What is purpose of ACL & what are command available

Ans : acledit , aclget & aclput)

83. How to copy acl from one file to another.

Ans : aclget file1 |aclput file2

84. How to view the extented permission.

Ans : ls -e filename

85. What is purpose of tcbck command.

Ans: verify the state of the files with the info in /etc/security/sysck.cfg

86. How to add a file sysck.cfg database

Ans : tcbck -a /home/rama/test12

87. Deleteting files from the sysck.cfg

Ans : tcbck -d /home/rama/test12

88. What is command used to analyze the system dump.

Ans : # crash imagefile kernelfilename

90. How to enable /disable the terminal

Ans : #penable & pdisable

91. How to set tty port for Bidirectionl mode ?

Ans :Share (port attributes )

How to see the Number of processor in the system ?

Ans : #lscfg -vp |grep Proc*

#lsdev -Cc processor

52. What is diffrence between sar & vmstat,iostat

Ans :Basic difference is SAR has time stamp but vmstat & iostat does not.

53. How to calculate CPU Ideal time & paging rate, what is

purpose of the same.

Ans : #Vmstat interval number - it is done to see the condition of the

system.

54. How to verify that system is CPU bounded or Resources

Bounded (memory & IO)

Ans :If %sys+%usr >= 80 average the problem may be CPU Bounded.

If the paging rate is >= 1 then more paging activity is there in the

system .it may be due to the memory or insufficient paging space.

55. How to increase the size of error log file.

Ans : # errdemon -s `size in bytes`

39. What is errpt? How the start & stop the error loging , how to

clear the error log.

Ans :Errpt is error-reporting program. Its reports the contains of file

/var/adm/ras/errorlog

2.)/usr/lib/errdaemon

3)errorstop

4.)errclear 0 (clear all errors )

40. What is the command used to see the Operating system level.

Ans : oslevel

41. How to see the fileset level ( bos.sysmgt.nim.master).

Ans: lslpp -l bos.sysmgt.nim.master

42. what is the smit past path used to upgrate to next modification

level.

Ans: #smit update_all

43. Where the installp command output is stored? (smit )

Ans : #$HOME/smit.log

44. What is the meaning of applied, commited, broken & absolute?

Status of filesets .

45. How to clean up the failed software installation.

Ans : #installp -C

46. What is the purpose of lppchk

#lppchk -c to verify the checksum

#lppchk -v to verify the software parts..

47. What are the parts of software components?

#root,usr & share parts.

Backup

Q2. What are the problems encountered during creation of mksysb?

Ans. If creation of mksysb fails then it may have the problems like:

1. If the particular files are missing, mksysb creation fails. In that case you

have to specify the files missing in /etc/exclude.rootvg and run mksysb with

-e flag in addition to the other flags.

2. Some times the Filesystem space is insufficient. This can be due to

installation of some new softwares. Normally the minimum Filesystem space

required is 2.2 GB. Rest it depends upon the no. of softwares installed.

97. What is purpose of image.data & bosinst.data

Ans # image.data contains information about VG & LVS

#bosinst.data contains ..information about the installation flow control

..like method of installation,prompted or not.

98. How to restore the mksysb image of one systems to other

system with different hardware.

Ans : Boot from the Installation CD , then choose to restore from mksysb

tape , so that if any additional driver is required it will copy from the CDROM.

99. How to take backup of rootvg

Ans : #mksysb -i /dev/rmt0

100. How to view the mksysb tape & how to restore particular file

from mksysb tape

Ans : # tctl -s4 -f /dev/rmt0

# restore -Tvf /dev/rmt0

# restore -xvf /dev/rmt0 filename.

101. How to rewind the tape.

Ans : # tctl -f /dev/rmt0 rewind

Networking

Q.43. How do I control how hostnames are resolved?

Ans.The default order can be overwritten by creating the configuration file,

/etc/netsvc.conf and specifying the desired order. Both the default and

/etc/netsvc.conf can be overwritten with the environment variable,

NSORDER. 12.What to disable telnet in AIX?

BIND, NIS, /etc/hosts

# export NSORDER=bind,nis,local

Q.32. How do I setup anonymous ftp on my AIX system?

Ans./usr/lpp/tcpip/samples/anon.ftp _ It is a shell script and will set up a

anonymous ftp site on your local RS/6000

Q.26. "no" command options especially 'thewall' parameter.

Ans. Network option _ Configures network attributes.

no { -a | -d Attribute | -o Attribute [ =NewValue ] }

Q13.What are the NFS Daemons?

Ans-Server End-nfsd, rpc.mountd, portmap, rpc.stated, rpc.mountd

Client End-bind,rpc.statd,rpc.lockd,portmap

Q18 What will you do if remote server is not connecting through ssh

or telnet?

Ans-For that we will login the server through HMC WSM and check the sshd

or telnet daemon.

20. Which is the main file where you specify host lookup order?

Q.15. What is Autofs ?

Ans. a) Used for automatic and transparent mounting and unmounting of

NFS File systems.

b) Based on AutoFS facility.

c) Uses automounter map files to find the mount directories and mount

arguments. Map can be text files or NIS maps.

d) automount command

e) automountd daemon

f) Client-side server

Benefits:

a) Reduces system administration of /etc/filesystems file particularly if

NIS maps are used

b) No pre-mounting of directories not currently needed thus reducing

possibility of client hang due to down server

c) Distributes client workload for NFS read-only file systems

Provides method for single-system image for clients

What is the difference between direct & indirect autofs?

Direct:

The automounts configured in an indirect map are all mounted under the

same local parent directory.

Inderiect:

The automounts configured in a direct map may be mounted in various

places in the local file system; they do not have to be located under the

same parent directory.

Q.15. What are different between hard and soft mount ?

Ans : Hard mount ill expect (wait) untill server responds, if it is offline in

this case system ill hang.

Soft mount ill expect within that period , if it is offline process ill be in

background, next service ill start.

Q.15. What are the daemons for NIS ?

Ans. ypbind, ypserv, yppasswd, portmap

HACMP

Q24.How to Configure HACMP setup?

Ans-1-First Install Aix5.1 on all nodes

2-Install the required ML (ML 09)

3-Install the HACMP file sets on all nodes. (cluster.es, cluster.es.cspoc

,cluster.license)

4-Assign the IP,s & Alias on all node

5-Configure /etc/hosts on all nodes it must be same for each node.

Now use # smitty hacmp and configure step by step as below-

I-Add a cluster---It will ask for a cluster Name

II-Add a node----add each node name

III-Run the Discovery process(After run this option it will create some files

as #/usr/es/sbin/cluster/etc/rhosts----Contains the base IP,s of node

#/usr/es/sbin/cluster/etc/config/clip_config—Contains the IP details of all

nodes.

/clvg_config—Contains the,PV,VG,Major numbers Details of

all the nodes covered within the cluster.

/haver.info—Contains the information about the HACMP

version.

IV-Add a Network

V-Add a communication Interfaces & Devices

VI-Add a persistent IP Label/Address

VII-Add a resource Group

VIII-Add a resource

IX-Put The Resource in Resource Group

X-Run the Verification and Synchronization—It will synchronize the changes

with other nodes within the cluster.

XI-Start the Clusters Service---#startsrc –g cluster--It will start all cluster

Daemons.

25.What is persistent IP?

Ans-This is a alias of standby interface used for Administrative purposes.

How to see version of HACMP

/usr/es/sbin/cluster/etc/config/haver.info

lslpp –l hacmp

How will you know which nodes are involved in clustering ?

clverify

Q26.If service IP Move to fallover node ,will persistent do same?

Ans-No this is node bound IP so it can not move to other node.

Q27.What are the HACMP Daemons?

Ans-clstmgr,clinfo,clcomd,cllockd,clmuxpd

Q29.How to see the Status of RG in HACMP?

#/usr/es/sbin/cluster/utilities/clRGinfo

Q30.What are the types to shutdown the RG?

Ans-There are three ways to shutdown the RG-

1-Gracefull shutdown without takeover--The Application will stop and RG will

release but it will not aquired by any node.

2-Gracefull shutdown with takeover--The Application will stop and RG will

Release and will takeover by fallover node.

3-Focefully shutdown--The application will shutdown but RG will not be

release,commands are--

#/usr/es/sbin/cluster/utilities/clstop -g

#/usr/es/sbin/cluster/utilities/clstop -gr

#/usr/es/sbin/cluster/utilities/clstop -f

Q31.What are the log files in HACMP?

Ans-/tmp/hacmp.out , /tmp/cm.log , /usr/es/adm/cluster.log,

/var/hacmp/clverify/clverify.log , /tmp/cspoc.log

1. What topologies are you using in HACMP?

If clstst is currupt how will u check the cluster status.

cldump

When sharedvg is extended is it required to synchronize the

cluster?

Yes

2. what is concurrent VG ?

Concurrent access feature enhance the benefits provided by an HACMP

cluster.Concurrent access allows simultaneous access to a volume group

on a disk subsystem attached

What are method for HACMP heart beat ?

Non-ip network, ip network, disk heartbeating

How to check priority list in HACMP ?

/usr/es/sbin/cluster/utilities/cIRGinfo

How to check HACMP heart beat information ?

Node1-> cat < /dev/tty1 Node1-> cat /etc/hosts > /dev/tty1

Lssrc –ls topsvcss

How to increase FS in sharedvg add disk in sharedvg ?

Through C-SPOC

What is sharedvg ?

Vg configured to serve more than one node in the HACMP enviroment.

Shared VG is physically connected to multiple nodes.

How to stop cluster services in one node ?

/usr/es/sbin/cluster/utilities/clstop –gr node

What is HACMP ?

HACMP is a s/w provides that ensure the availability of these application,

the application are put under HACMP control. HACMP takes measures to

ensure that the application remain available.

3. What is cascading, concurrent and rotating RG?

4. How will you configure application on HACMP?

1. Application must be install on every node

2. Check in statnd-alone mode application is working properly on every

node

3. Make start.script and stop.script

4. Configure the application server

5. Put this application server as a resource in RG

What is disk heartbeat? How will you configure it?

Disk heartbeat is another form of non-ip heartbeat that utilizes the existing

shared disk of any disk type. As it eliminates the need for serial cable / 8-

port asynchronous adapter. It also can easily greater distance between

nodes when using SAN environment.

This feature requires using enhanced concurrent volume group to allow

access to the disk by each node as needed. It utilizes a special reserved area

on the disk to read and write the heartbeat data. Since it is used reserved

data, it allow the use of existing data volume group without losing additional

storage space.

11.How to configure heart beat in non-ip environment?

We have initialized tty terminal using #smit tty

Select /dev/tt0 ot /dev/tty1 (for rs232)

# smitty hacmp

extended configuration

extended topology

add a network

rs_232 network type rs_232_01

network rs_232

add a communication interface/devices

communication device

rs_232_01 node1

/dev/tty1

rs_232_01 node2

/dev/tty1

13.Suppose synchronization is not occurring in HACMP after making

changes and discovery process, what may be the reasons and how

will you troubleshoot?

How to configure RAID in SSA

Used smitty raid

14.What are the ways to configure HACMP?

IPAT with replacement

IPAT with aliasing

2. What is /tmp/hacmp.out?

A. contain formatted messages generated by HACMP for AIX script.

B. In verbose mode, this log file contains a line-by-line record of

each command executed in the scripts, including

2. What are the type of RG

1. cascading 2. Rotating 3. Concurrent

What are the consideration before you install HACMP?

IPAT planning

Resource group planning

H/W support

Application compatibility

What problem u faced while configuring HACMP and solution?

In discovery

what is C-SPOC

Cluster single point of control, which can be used to administrate entire

cluster.

How will you configure shared vg,

A. give the detailed procedure in a two node cluster

node1:

#lspv

#cfgmgr -l ssar

#lsdev -Cc disk

node 2:

#lspv

#cfgmgr -l ssar

#lsdev -Cc disk

find common pvid

Find free major number in both nodes

#lvlstmajor

create vg using common major number

#smitty mkvg

myvg

--->automatically vg should be varied on - No

--->Quorum - No

#smitty mklv

loglv

type jfslog

#logform /dev/loglv

#smitty mklv

datalv

type jfs

#smitty crfs

mount point /data device /dev/datalv

#mount /data

umount /data

varyoffvg myvg

node 2:

import the myvg from node1 using importvg command

4.What is service ip , bootip and standby ip

A. service ip address: ip address used by client user

bootip address : ip address configured on base interface

standby ip address : ip address configured on standby interface

5.Startup, Fallover and Fall back policies. (What are the policies in

hacmp?)

A. Startup policy:

1. Online on home node only

2. Online on first available node only

3. Online on all available node

4. Online using distribution policy

Fall over policy:

1. Fall over to next priority node in the list

2. Fall over using dynamic node priority

Fall back policy:

1. Fall back to higher priority node in the list

2. Never fall back

LPAR

Q19.What is HMC and what is the difference between LPAR & DLPAR?

Ans-This is (Hardware management console) a Linux based preloaded

machine used to configure & Maintain LPAR & DLPAR.

LPAR is Logical-partitioning means we can create the multiple partition of a

server box and can separately run different OS on that. But in DLPAR

(Dynamic LPAR) we can move the resources (CPU, Memory, I/O Ports) from

one partition to another with the help of HMC.

Q20 What is Dedicate & Shared CPU?

Ands-Dedicated CPU means we will assign the full CPU to a single partition

but in shared mode we can assign a single CPU to Multiple partitions.

Q21.What is Micro partitioning?

In-In Micro partitioning we can Assign a single CPU to Multiple partition. First

assign 0.1 then it can be extend by .01

What is the cpu allocation level in micro partitioning?

0.1

Q22.What is Caped & encaped?

Ans-This is used in micro partitioning when a CPU value assign to a partition

and it is using some percentage of assign value and rest is free

Then it will call caped and if this free value is get move to other partition

then it will call encaped.

Q23.What is entitle capacity?

Ans-This is Assign value to a partition.

How to moved the resources dynamically within the profile.

Through HMC we have to delocate the resources from one profile and attach

the resources in other profile.

How to create LPAR on 2 processor and 32 GB RAM?

Log into HMC as hsroot with the password and go to server management in

navigation and right click mouse to create partition on 2 processor and 32

GB RAM and then activate partition.

How to create HMC user on HMC in command line.

#mkhmcusr to create and chhmcusr to manage user.

How to update microcode in HMC?

Login into HMC as hsroot and go to management environment in navigation

area then go s/w maintenance option then microcode update.

NIM

103. What NIM & Purpose

NIM is Network installation management - where client system softwares

can be installed from the NIM master.

104. How to list nim objects.

# lsnim

105. Is it possible to install the mksysb to alternate disk by nim.

Yes ..its possible

What is minimum requirements for NIM

SPOT(boot image), lpp_source(fileset)

Location of lpp resources file

/export/spot1 and /export/lpp_sources/lpp_source1

How to configure NIM Client

In client machine go o SMS menu /Utilities / RIPL / Assign IP address of

NIM master.

Goto sms menu and specify the client and master ip address and make

Ethernet the firs boot device.

Q.29. What is SPOT? Or Explain SPOT ? Is it part of NIM ?

Ans. The SPOT contains the directory structure for an installed /usr file

system. It also contains subdirectories for the "root" parts of installed

filesets. Since the SPOT contains both usr and root files, software

maintenance must be performed on the SPOT in order to update the

software that is running on the clients. Such actions must be performed

using the NIM cust and maint operations.

Spot is used by the client during NIM install or boot. The following

operations are performed to manage the software for diskless and dataless

clients:

1. The /usr files are installed in the SPOT. These files are automatically

seen by all the clients that mount the SPOT as their /usr file systems.

2. The root files are installed in special subdirectories in the SPOT.

3. After all the filesets have been installed in the SPOT, the root files are

copied to the directories of any diskless or dataless clients that have

been initialized with the SPOT

AIX Interview Questions

Base Kernel

Question: The system is performing very slowly; you have discovered that

this is due to an increasing number of defunct processes are being created.

How can you determine the cause?

Answer:

1. Check to see if new defunct processes are being created, owned by the

init process, with no processes being deleted at all.

2. If some defunct processes are being cleared out and the overall number

of defunct processes is still growing, then this is due to an application

creating more defunct processes than the init process can clean out.

3. However, if NO defunct processes owned by init (PID 1) are being cleared

out, this points to an incorrect wait entry in the /etc/inittab file. The init

process is stuck on this wait entry and will not cycle through the defunct

processes until that entry finishes. The solution is to change that “wait”

entry to a “once” entry.

Question: You get a message that the system can’t fork any additional

processes? What do suspect to be the problem?

Answer: Either paging space is full or maxuproc (maximum number of user

processes) is set too low.

Question: You’re running some commands and getting an error that says

“srcmstr daemon is not running”. Obviously, it is, because the machine

appears to be functional. What is the likely cause?

Answer: Someone has updated some of the base kernel filesets without

rebooting the machine.

Question: Describe one situation where it might be appropriate to edit the

ODM.

Answer: E.g., need to make parameter changes to a device that is open,

and that cannot be modified without closing the device (i.e., a network

device), and where the machine can be easily rebooted following the

change.

Question: When might the savebase command be used?

Answer: After making manual changes to the CuAt, CuDv, CuDvDr, CuDep,

or CuVPD ODM classes (aka the device configuration database), these

classes must be saved into the boot image in the boot logical volume. If

they are not saved, there is a risk run that the changes won’t be saved at

boot. Note that the chdev command (and others) will cause savebase to be

run.

Question: How do you properly mirror rootvg to protect the OS from

crashing should a disk fail?

Answer:

1. Use the mirrorvg command to mirror the logical volumes

2. Run the bosboot command to reboot the boot image and update the

disk boot record on both disks that contain a copy of the boot logical

volume.

3. Run the bootlist command to add both disks to the boot list.

4. Mirror all non-rootvg paging spaces as well as those in rootvg.

Dump device?

Paging space?

Question: Why is it important to mirror non-rootvg paging spaces, and

what might be the effect if this is not done?

Answer: The OS allocates pages in a round-robin fashion across all paging

devices. If a non-rootvg disk containing a paging space fails, the system will

likely crash unless it is mirrored. Putting paging spaces on RAID disks is not

recommended due to the performance implications.

Question: Provide the steps to move a file system from one volume group

to another WITHOUT recreating and restoring it.

Answer:

1. Unmount the file system

2. Use the cplv command to copy the logical volume to the new volume

group.

3. Use the chfs command to update the dev and log entries for the file

system.

4. Run fsck.

Question: Why is directly editing /etc/filesystems, to change information

for a file system, a bad idea?

Answer: The entries from /etc/filesystems are usually stored in the logical

volume control block for each logical volume. If you ever had to run

importvg for this volume group (i.e., after a reinstall or if using HACMP), the

changes would be lost.

Question: The “df” command shows that the file system is 100% full, but

“du” shows no files in the file system. Why, and how do you debug this?

Answer: A running process is holding open a file descriptor that references

a large amount of space either not saved as a file or references a file that

has been deleted. Use “lsof” or “fuser” to track down this process.

Question: What steps should you follow to replace a failed hdisk?

Answer:

1. Remove all allocated logical volumes (if not mirrored) or LV copies (if

mirrored).

2. Remove disk from the volume group.

3. Remove disk definition (and pdisk, if it’s an SSA drive mapped 1-to-1)

4. Physically replace disk

5. Run cfgmgr.

6. Add disk to volume group and recreate LVs or LV copies.

Network

Question: Where is the default gateway stored in AIX? Where are other

routes stored?

Answer: As ODM entries in the CuAt ODM class.

Performance

Question: A project manager claims that a system is CPU-bound. What

commands do you run to verify this, and what sort of output are you looking

for?

Answer:

1. Run vmstat and look at the wait, idle, CPU utilization, runq and blockq

parameters.

2. A CPU-bound system will exhibit relatively low wait and idle

percentages and a high degree of CPU usage.

3. In addition, the runq parameter will average the number of CPUs on

the system and the blockq parameter will be, on the average, high.

Question: You have a 32-way Regatta. Why is vmstat not an accurate tool

to measure CPU utilization for each processor? Or what is the difference

between SAR and vmstat?

Answer: vmstat takes a system average. The SAR command can show the

CPU utilization for a particular processor.

Installation Issues

Question: Define under what circumstances two different versions of a

product can coexist on the same machine in AIX.

Answer:

1. The names of the filesets for that product are different when stored in

the ODM.

2. The product does not store names in the ODM.

Question: What considerations do you need to make when cloning system

X to system Y?

Answer: Make sure that all the drivers needed for system Y and its

associated hardware are included in the image for system X.

lslpp -w ” to see what fileset provides that command.

lslpp -f ” to see what files are installed by that fileset.

AIX Patches and Maintenance

Question: Discuss your strategy for applying and committing

maintenance

Answer:

• A prudent administrator will generally apply fixes first if those fixes have

never been used before in the environment.

• After an evaluation period, the fixes can be committed.

• Subsequent installations of those fixes on other machines can then be

committed.

• If these fixes are related to the base OS, a mksysb should be created

first.

Question: Describe the difference between a PTF, and APAR, and a

maintenance level.

Answer: An APAR is a specific patch that may update one or more filesets.

A PTF is an IBM term for a collection of APARs commonly shipped together

as a common fileset update. A maintenance level is a collection of APARs

(also generally ordered as an APAR).

Question: What is the difference between applying and committing an

APAR?

Answer: Applying it saves the old versions of the files so that you can back

off the new version. Committing the APAR removes the old versions.

Question: List some common sites to download freeware tools for AIX?

Answer: aixpdslib.seas.ucla.edu

purdue.edu

www.bullfreeware.com

IBM repository of Linux freeware for AIX

List filesets that are below the AIX 4.3.2.0 maintenance level

oslevel -l 4.3.2.0

Which_fileset to identify which fileset needs to be installed

List known AIX maintnenance levels

oslevel -q

3. How to replace physical volume in hacmp? (From sharedvg while

online)

First take the backup of that disk and inform to all client, which are

login by server.

Use smitty hacmp -> C-SPOC -> HACMP physical volume management

-> Add a source disk -> add a destination disk.

4. How will you replace falling disk mirrored rootvg?

• unmirrorvg rootvg diskname

• chpv –c faileddiskname

• reducevg rootvg diskname

• rmdev –dl diskname

• Add new disk and configure using cfgmgr

• extendvg rootvg diskname

• mirrorvg rootvg diskname

• syncvg –v rootvg

• bosboot –ad /dev/diskname

• Set bootlist

5. Difference between AIX5.1 5.2 and 5.3

AIX 5.1

• Jfs2 file system is introduced

• Support both uni and multiprocessor.

AIX 5.2

• DLPAR

• System scalablity

• Jfs2 file system upto 16TB

• DuoD-Dyanamic capacity upgrade on demand

AIX5.3

• Scalable vg introduced

• Support only multiprocessor kernel

• Variable Logical Track Group size

• Shrink file system support

• Dump procedure is enhanced to use nvram to store minimal

dump info.

6. What is the stanza of lsvg –l rootvg?

Lvname, type, lp, pp, pv, lvstate, mount point

7. What is the procedure to configure LPAR?

Typically all partition creation and management is performed through

the H/W(HMC). The CLI is an advanced option and still requires and

HMC.

TASK No Description Comment.

Start the partition wizard

Partion name ID and type

Workload management participation

Partition profile name

Partition profile memory values

Partition profile processor value

Partition profile interactive value (if available)

Allocation of physical I/O resources

Allocation of virtual I/O resources.

8. What is the stanza of /etc/security/login.cfg?

It contained parameter related login info like max time login, login

delay, logindiabled etc.

9.

10. What is /etc/security/limit?

It contained resource limit a user can use. Resources like no of CPU,

amount of RAM, size of file etc.

11. What are the major problems you are attended I

your setup?

Generally I faced file system full, performace problem, booting problem,

and network problem, disk failure, Ethernet adapter failure, memory

problem, and loose connection of cables.

12. If the user login, the system is very slow, what

steps you will follow?

Entry is available in /etc/noloign for that user, root should remove this

entry then only user can login.

13. What is the snap and its. Output directory?

Snap is used to format dump o/p and send to IBM. /tmp/ibmsupt/genral

14. In production environment what is the procedure

to down the application?

Inform team leader and IT head and take permission. Inform all users

to logout, who is login.

We used in commercial tax

First shutdown report server by stopping service

Second shutdown application server by stopping service.

Then shutdown oracle database server then if necessary power of all

machine.

15. umask value for security references?

027

16. How to change the PP size, which already exists

VG? Is it possible? Tell the procedure?

Change pp size by opening vi /image.data

Create mksysb using I option

Then restore mksysb

17. If user complaint that the system is very slow,

what step you will follow?

Check where the system resources is overloaded by performance tool.

Kill that process, which are using more resources with the consultation

with team leader & IT head. And inform all the users who is login?

What are the function VIO servers?

Ans: - VIO is special purpose partition that provides Virtual I/O resources to

lpar (client) partitions. The VIO server owns the real resources that are

shared with other clients. With VIO technology, you can assign a physical

adapter to a partition to be shared by one or more lpar, enabling clients the

minimize their number of physical adapter, you can use VIO server to reduce

costs by eliminating the requirement that each lpar has a dedicate network

adapter, disk drive.

To ensure stable performance, it is preferable to use the VIO server in a

partition with dedicated resources.

NIM setup

1. NIM Initialization:

nimconfig –a pif_name=en0 –a cable_type=tp –a netname=dcm –a

platform=rspc

2. LPP source:

a. Nim –o define –t lpp_source –a location=/nim/lppsource –a

source=/dev/cd0 –a server=master spot_aix51 ( for creating

object spot)

SPOT:

nim –o define –t spot –a location=/nim/spot –a source=/dev/cd0 –

a server=master lpp_sourceaix5 ( for creating object lpp_source)

Machine Definition:

Use nimdef command – for that first creates a defination file

Nimdef –p –f cws.def (for preview of machine definition)

Nimdef –d –f cws.def (for adding of machine definition)

niminit (to initialize client)

nimclient (to manage nim operation)

format of machine file

cws:

machine_type = standalone

Subnet_mask = 255.255.255.0

Gateway = 0

Platform = rspc

network_type = ent

cable_type = tp

comment = “ this is cws machine”

Q1-What are all file systems type in AIX?

A.jfs ,jfs2 ,nfs ,cdrfs

Q2- what is the output of Who command?

A. username pts date ip etc

Q3.How to check how many systems are running in the network?

A.who

Q4.How to check on what operating systems you are working?

A.uname

Q5.How to check the model of hardware box?

A. prtconf

Q6How to check AIX version?

A. oslevel

Q7.What is the significance of 5.1.0.0 ?

A. version,release,modification,fix

Q8.How to see the maintenance level ?

A. oslevel -r

Q9.what is lpp ?

A. licensed program product

Q10.How to install software on AIX?

A. smit install

Q11.What all you can do thru SMIT ?

A. lot of activities like making volume group,logical volume,creating

filesystems ,installing softwares

Q12.How to check paging space ?

A. lsps -a

Q13.How to create a file system?

A.refer CSC quest

Q14.How u will connect raw hard disk ?

A.1)connect it physically to the system,2)run cfgmgr 3)add it to volume

group

Q15.After running cfgmgr,how to check, which HDD is added?

A. using lspv command

Q16What is the output of lspv ?

A. hdisk pvid vg name

Q17.while adding a new HDD to AIX it shows that it is a part of another

VG,how to fix this problem?

A.1)clear pvid (using chdev -l hdiskn -a pv=clear) of the hard disk 2)now

use chdev -l hdiskn -a pv=yes

Q18.how to create LV ?

A. mklv -y testlv -t jfs rootvg 20 hdisk0

Q19.How to create LV command line?

A.mklv -y testlv -t jfs rootvg 20 hdisk0

Q.20how to find PP size?

A.lsvg vgname (the o/p of this command gives detail of vg including ppsize)

Q21.What is Stale PP?

A.unsynchronised pps are stale pps

Q26.how to check routing table?

A netstat -r

Q27. what is the output of mount command?

A.it shows mounted file systems only

Q28.what is there in etc/filesystem ?

A.it contains filesystems stanzas (details like filesystem type, log location,

mountpoint details,permissions etc)

30.How to edit crontab ?

A.crontab -e

Q31. What is at ?

A. used to schedule a job once only

Q32.how u will check whether AT executed ?

A.ps -ef

Q33.how to install fix?

A.instfix -k fixname -d /dev/rmt0

Q34. how to change the file system size ?

A.refer CSC quest

Q35.How to take rootvg VG Backup ?

A.mksysb

Q36. what is savevg ?

A command to take backup of vgs other than rootvg

Q37.how to see the location of RG in HACMP ?

A. ./clstat

Q38.what is log file in HACMP?

A. /tmp/hacmp.out

Q39 how to check HACMP is running ?

A. lssrc -g cluster

Q40What is inittab ? what is there in first two line of innittab?

A.file used for intialization of system. First two lines contain init process and

run level

Q41.What is init 0?

A.used to shutdown system

Q43.how u will check running processes ?

A.ps -eaf

Q44. what is the output of ps -ef ?

A.pid ,ppid,time etc.

Q45. How to monitor system performance. What is sar ?

A. using sar,vmstat,iostat . Sar is used for seeing CPU performance.

Q1.How to check Usage on a particular file system ?

A.fuser -u /etc/filesystems

Q2.How to check the model of hardware box?

A.lscfg -vp

Q3.what is the output of who command ?

A username pts time ip

Q4.what is PV ?

A.physical volume

Q5.How to check PVs in a volume group ?

A lsvg -p vgname

Q6.what are PP ?

A physical partition

Q7. What is the Min. & maximum size of PP?

A min 1mb and max 1024mb

Q8How to create a file system?

A refer CSC quest

Q9.How to add a new HDD ?

A extendvg vgname pvname

Q10.How to change password of user ?

A passwd username

Q11. what is the location of password file ?

A /etc/security/passwd

Q12.which file is updated after changing user password?

A. /etc/security/passwd

Q1.How do u rate yourself on AIX?

A.

Q2 How to check version of OS ?

A oslevel

Q3.How to check disk usage ?

A lspv pvname

Q5.How to check IP Address of a systems?

A.ifconfig -a

Q6.how to check the routing table ?

A.netstat -r

Q7.How to check total memory ?

A.lsattr -El mem0

Q8.how to check default gateway ?

A.netstat -r

Q9.How to create user ?

A.mkuser username

Q10How to check SMIT log ?

A in home directory of user view smit.log

Q11.How to mount file system ?

A.mount filesystemname mountpoint

Q12.How to check ,what are the available Pvs?

A.lspv

Q13.How to check which directory is shared in NFS?

A.exportfs -v at server and showmount -e server hostname at client

Q14. How to change size of file system ?

A.refer CSC quest

Q15.How can you reset user password ?

A.passwd username

Q16.where password is stored ?

A. /etc/security/passwd

Q17.Can any ordinary user edit etc/security file ?

A no

Q18. what are schedular available ?

A at, crontab and batch

Q20. How can u check AT is executed ?

A.see atlog in /var/spool/cron

Q21.How to list contents of Crontab File ?

A.crontab -l

Q22. How to edit crontab file ?

A.crontab -e

Q23.what is crontab -r

A.for deleting entries in crontab file

Q24. How will u check hardware error ?

A.errpt -d H

25.what is daemon for errlog ?

A.errdemon

Q26. How to check cluster service is running or not ?

A.lssrc -g cluster

Q27 What is log file in HACMP ?

A. /tmp/hacmp.out

Q28. How to check running processes ?

A. ps -eaf

Q29. what is PID,and PPID ?

A process id and parent process id

Q30.How to stop a process ?

A command ( kill) to stop init process and stopsrc to stop processes

controlled by src

Q31.How to check perforl mance of a system ? what are commands ?

A. sar, vmstat and iostat

Q32.what is the file system for /usr ?

A /dev/hd2

Q1. How do u rate yourself on AIX ?

Q2.How to check Total memory of a system ?

A.lsattr -El mem0

Q3.how to change paging space ?

A.chps -s 10 paging00 (adds 10 LPs to paging00)

Q4.Where does paging space exits ?

A /etc/swapspace

Q5.in which booting phase /etc/swapspace is executed ?

A.

Q6.How to check os version ?

A oslevel

Q7.How to install fix ?

A.refer earlier quest

Q8.what is lpp

A licensed program product

Q9. what lpp stands for ?

A licensed program product

Q10.how to check running process ?

A ps -eaf

Q11.what is PID and PPID ?

A process id and parent process id

Q12.what is SRC ?how does it works ?

A. system resource controller

Q13.how to check cluster services is running or not ?

A.lssrc -g cluster

Q14.how to check the hardware model of a systems ?

A.lscfg -vp

Q15.how to check IP address

A ifconfig -a

Q17. how to check Media speed ?

A

Q18.what is routing ?

Ait is used for communicating between different networks

Q19. How can u add route ?

A routeadd command

Q20.If botable hard disk fails how can u recover the system ?

A. add another hard disk to the system and restore os by mksysb tape

Q21.What is there in inittab ?

A.processes ,daemons ,run level etc.

Q22. what is scheduler ?

A cron is schedular

Q23. how do u edt crontab file ?

A.crontab -e

Q1.What all are your day to day activity ?

Q2.howto check hardware model ?

A.lscfg -vp

Q3. how to check Os version ?

A oslevel

Q4.how to install fix ?

A refer earlier quest

Q5.how to check hostname ?

A.hostname

Q6.how to check IP address ?

A ifconfig -a

Q7.what is the output of ifconfig ?

A interfaces, ips etc

Q8.how to check routing table ?

A netstat -r

Q9.how to check shared directory on NFS ?

A. exportfs -v

Q10.what is there in inittab file ?

A processes ,daemons and run level

Q11.what are the run levels ?

A 0-9

Q12. what are type of installations ?

A new and complete overwrite, preservation and migration

Q13.what happens in preservation installation ?

A /usr, /var, / tmp and / directories are overwritten

Q14.How to go in maintenance mode on running system ?

A shutdown -m

Q15.if a file system is corrupt how to fix it ?

A fsck command

Q16. how to check PVs in a system ?

A lspv

Q18.How to check mirrored volumegroup

A lsvg -l vgname

Q19 what you will do if u are unable to execute a file ?

A give execute permission to that file

Q20.how to check user password has not changed since last six working

days

A.

Q21.what are all performance monitoring command ?

A sar,vmstat and iostat

Q22.How u will check availability of a resource group ?

A cd /usr/es/sbin/cluster .here run ./clstat

Q23.What is fall Back policy ?

A options in this policy are

1)fall back to higher priority node in the list

2)never fallback

Q 1. Tell me about yourself?

Ans.

Q 2. What is your current setup?

Ans

Q 3. What is NFS and which daemon it is using, what is configuration files?

Ans. NFS is network file system which use for sharing file on the linux/unix

plateform.

Server side daemons are- portmap, nfsd, rpc.mountd, rpc.statd,

rpc.lockd

Client side daemons are- portmap, biod, rpc.statd, rpc.lockd

Q 4. What is portmap?

Ans. It provide port no for client request

Q 5. How to increase filesystem size?

Ans. Chfs -s +size= m,g /filesystem

Q 6. What is difference between RAID 0 and RAID 1?

Ans Raid 0 is used for striping purpose and Raid 1 is using for mirroring.

Q 7. What is swapon and swapoff commend?

Ans Swapon turn on paging space and swapoff used to turnoff paging page

Q 8. What is mksysb?

Ans It’s a command which used to take backup of rootvg

Q 9. What is difference between jfs and jfs2?

Ans There are following difference-------

jfs jfs2

1-Inode size 128 Byte 512Byte

2-Max file size 64GB 4PB

3-Max filesystem size 1T 4PB

4-Cmpresion yes no

5-jfslog-type General jfslog inline-jfslog

Minimum file system size not specify 16MB

Inode allocation static dynamic

Q 10. How to start mountd daemon?

Ans startsrc -s mountd

Q what is path?

NIM Commands Reference

How to define a standalone machine in NIM.

nim -o define -t standalone \

-a platform=chrp \

-a if1="subnet-74 FQDN of Machine 0" \

-a cable_type1=tp \

-a net_settings1="speed duplex" \

-a netboot_kernel="up or mp \

name of resource

How to initiate an install of a machine from a mksysb image.

nim -o bos_inst \

-a source=mksysb \

-a spot=aix520-01_spot \

-a mksysb=base520-02-64bit_mksysb or base520-02-

32bit_mksysb \

-a accept_licenses=yes \

-a preserve_res=yes \

-a installp_flags="cNgXY" \

-a fb_script=osg-mksysb-install_firstboot \

name of resource

If you do not want the machine to be rebooted right now, then add the

following:

-a no_client_boot=yes

How to reset the NIM state of a machine.

nim -o reset \

name of resource

You can add the following to force a reset

-a force=yes

If after you try to reset the state and try to install again and you are told

that the resource is still allocated run the following:

nim -Fo deallocate \

-a subclass=all

name of resource

How to take a mksysb of a machine.

nim -o define -t mksysb \

-a server=master \

-a location=/export/nim/mksysb/.mksysb

\

-a source=name of resource \

-a mk_image=yes \

-a exclude_files=osg-default_exclude \

name of the mksysb

How to make a NIM exclude file.

nim -o define -t exclude_files \

-a server=master

-a location=/export/nim/misc/osg-default.exclude \

osg-default_exclude

How to define a script resource in NIM.

nim -o define -t script \

-a server=master \

-a location=/export/nim/misc/.sh \

name of resource

How to define a firstboot script

nim -o define -t fb_script \

name of the mksysb

How to remove a NIM resource.

nim -o remove \

name of the mksysb

Updating installed software

nimclient -o cust \

-a lpp_source=lpp source \

-a installp_bundle=installp bundle

Q 1. Tell me about yourself?

Ans.

Q 2. What is your current setup?

Ans

Q 3. What is NFS and which daemon it is using, what is configuration files?

Ans. NFS is network file system which use for sharing file on the linux/unix

plateform.

Server side daemons are- portmap, nfsd, rpc.mountd, rpc.statd,

rpc.lockd

Client side daemons are- portmap, biod, rpc.statd, rpc.lockd

Q 4. What is portmap?

Ans. It provide port no for client request

Q 5. How to increase filesystem size?

Ans. Chfs -s +size= m,g /filesystem

Q 6. What is difference between RAID 0 and RAID 1?

Ans Raid 0 is used for striping purpose and Raid 1 is using for mirroring.

Q 7. What is swapon and swapoff commend?

Ans Swapon turn on paging space and swapoff used to turnoff paging page

Q 8. What is mksysb?

Ans It’s a command which used to take backup of rootvg

Q 9. What is difference between jfs and jfs2?

Ans There are following difference-------

jfs jfs2

1-Inode size 128 Byte 512Byte

2-Max file size 64GB 4PB

3-Max filesystem size 1TB 4PB

4-Cmpresion yes

no

5-jfslog-type General jfslog inlinejfslog

Minimum file system size not specify 16MB

Inode allocation static dynamic

Q 10. How to start mountd daemon?

Ans startsrc -s mountd

Basic (generic) Administration

1. How do I find out who is logged into the system?

Ans : who,w

2.What are the fields in the password file?

Ans : user:pw:uid:gid:gcos:home:shell

3. What steps to setup a new user?

Ans :/etc/passwd, home dir, permissions

4. What directory is typically used as scratchspace?

Ans : /tmp

5. How do I stop a UNIX system?

Ans : halt,init,shutdown

6. Name some top-level (under /) directories?

Ans : (etc,bin,usr,var,tmp)

7. How do I install a new printer?

Ans : lpadmin, /etc/printcap

8. What does fsck do?

Ans : fixes filesystems (no AIX)

9. Explain the concept of virtual memory. Physmem, Swap, and paging.

Ans :

10 . What kind of permission would “chmod 755” yeild on a file?

Ans : U = rwx, g/o rx

11. What is an “s” in a file’s permission mean?

Ans : setuid

12. What does a “b” as the first letter of a file’s permissions mean?

Ans : block special

13. How do I make a new disk available for files?

Ans : mkpart/newpart,mkfs,mount (no AIX)

14. If I’m logged in as root, what command lets me “become” another user

id?

Ans : su

15. What’s the difference between “su” and “su -“?

Ans : su - run’s the user’s login files

16. What command will tell me how busy the system is? (load average)

top,sar,iostat,vmstat

How do I see what print jobs are pending? lpstat, lpc stat, etc..

How do I setup a printer? lpadmin, printcap, YMWV

What’s the startup files for the C shell (or Bourne)? .login/.cshrc or .profile

What is /etc/aliases? mail aliases for systems

What’s the current version of your OS? SunOS 5.x/2.x, HPUX ~10, AIX ~4,

IRIX 5/6,etc..

Advanced Administration

These questions separate the men from the boys.

What is /etc/inittab? Startup sequence file

Where is the “main” mail configuration file for a system? sendmail.cf

What is the first process to start on a UNIX system, after the kernel? init

What is an inode? pointer to block of disk, referenced in a directory

What does the ipcs command do? shows status of System V IPC structures

What is the Changed time on an inode/file mean? Last time the inode was

modified

What’s an indirect block? Pointer to a list of blocks

What is an X Server? graphical display device, optional

What are two X Clients? xterm, xclock, netscape, CDE, etc...

What is RAID? Redundant Array of Independant Disks, striping, mirroring,

etc..

How do I change the priority of a process?nice, renice, priocntl (SysV.4)

UNIX Network

What is a web server? What is a web client? place with pages,

netscape/msie

How can I copy a file from one system to another? ftp,rcp

What command lets me remotely log into another system? telnet,rsh

Give an example of a domain name? dcicorp.com, ford.com

Give an example of a host name? varies widely

Networking Administration

What is an IP address? 32-bit Internet Protocol ID Number

What is a subnet? logical/physical grouping of systems by IP/Subnet

What is a MAC accress? ID number burned into every ethernet card

What is a hub? common: same-subnet, same-collision domain ether

connection

How do I test to see if a system is setup on the network correctly? ping

How do I display the route table? netstat, route

What’s in the inetd.conf file? Internet daemon info

What is DNS? heirarchical network naming system, Domain Naming System

What features of Anonymous FTP make it secure?chroot’ed environment

What is NSLOOKUP? tool for querying names/addresses in DNS

What are RPC’s? Remote Procedure Calls

What is an A record? primary name->ip address mapping

What is an MX record? mail domain mapping record

What is NFS? Network File System

How do I setup a system as an NFS server? share,/etc/exports,sharetab,

etc..

How do I setup a system as an NFS client? mount, mount tables

What is SMTP? Simple Mail Transport Protocol

What is traceroute? IP routing utility

How does traceroute work? declining TTL in IP header

Security

What are shadow passwords? unreadable password files

What is an rhosts file? Why is it bad? Bezerkley trust, can be abused

Why are set-uid shell scripts a bad idea? unexpected shell expansion

What is SSH? Secure Shell

Explain (briefly) Kerberos? Ticket-based scheme for authentication

What is the problem with running fingerd(1)? Gratuituous information

Sendmail is currently at what version? 8.x. If they don’t use sendmail,

hooray

Who is CERT? What do they do? Computer Emergency Response Team,

issue advisories

Perl

What does the @ in a variable indicate? its an array

What’s the current version of Perl? 4 or 5, prefer 5. 5.005 is MRV

What is a Hash? a key-data pair type of array variable

Generating dump testcase

snap -Dc

File is stored in /tmp/ibmsupt/snap.pax.Z

Extracting testcase

File is stored in /tmp/ibmsupt/snap.pax.Z

uncompress snap.pax.Z

List toc: snap -f snap.pax

Extract: pax -rf snap.pax (creates subdirectories called dump and testcase;

dump contains unix.Z and dump.Z)

Check for last dump

sysdumpdev -L

Note the dump device (/dev/lg_dumplv or /dev/hd7, for instance)

To open dump (AIX 4)

crash /dev/hd7

• stat

• trace -km

To open dump (AIX 5)

kdb /dev/lg_dumplv

• stat

• trace -km

To verify dump configuration

sysdumpdev -l

sysdumpdev -e

1.How can u change IP of one node in HACMP environment ?

A- SMIT TCP/IP

Q2. How to fix if a external storage is visible to one node and not to other

node in HACMP?

A- Using chdev command I will make PVID=yes and command is chdev -l

hdiskn -a PV=yes

Q3.How can u increase file system size in HACMP ?

A- Through C-SPOC

Q4.How to Fix if a VG is not Available in ODM?

A- smit importvg

Q5. What is heart beat in HACMP ?

A-heartbeat is used for health monitoring of nodes(whether or not nodes are

alive)

Q6.What is disk heart beat in HACMP ?

AQ

7.What are the basic requirement for two nodes to be configured in

HACMP?

A-each node should have two NICs, hardware should be

same(recommended) and OS and ML must be same

Q8.how to check whether a node is in cluster ?

A- using ./clstat

Q9.What is the daemon for HACMP?

A- clstrmgrES, clsmuxpdES,clinfoES and clcomdES

Q10.What are the permissions in AIX ?

A- read, write,execute ,SUID,SGID, Sticky bit

Q11.How to give all permission, only to user of a file ?

A- chmod 700 filename

Q12.How to set UID ?

A- chmod u+s filename

Q13.How to set GID?

A- chmod g+s filename or dir

Q14.How to create file system on new hard disk?

A- i)extendvg vgname hdiskn

ii) SMIT mklv, iii) SMIT crfs

Q15.How to increase file system size ?

A- chfs -a size=+no. of blocks /filesystem name

Q16.How to check which file system is available on which PV?

A- First check on which LV filesystem exists,say lv00, now use command lslv

-m lv00

Q17.What is command to list applied and committed software?

A- lslpp -l

Q18.By which command u can change applied state to committed state ?

A- installp -c -f software name

Q19.How to check ML level ?

A- oslevel -r

Q20.how to transfer boot image?

A- using bosboot command(eg. bosboot -a -d /dev/hdiskn)

Q21 how to replace faulty HDD ?

A-It depends on scenerio

Q22.how to check if a VG is mirrored?

A- lsvg -l vgname

Q23. How to check system configuration ?

A-prtconf

Q24.What is spooler ?.

A-a daemon

Q25 what is daemon for spooling ?

A- spooler

Q26.What is alog from where it takes info ?

A- command for seeing boot logs, takes info from var/adm/ras

Q27.Who command takes info fronm where ?

A- /etc/utmp

Q28.What are repository in ODM ?.

A- /etc/objrepos, /usr/lib/objrepos, /usr/share/lib/objrepos

Q29.how to list customized devices ?

A- lsdev -C -H

Q30.What is ODMGET ?

A- command to get information from ODM