Tanti Technology

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Multi-platform UNIX systems consultant and administrator in mutualized and virtualized environments I have 4.5+ years experience in AIX system Administration field. This site will be helpful for system administrator in their day to day activities.Your comments on posts are welcome.This blog is all about IBM AIX Unix flavour. This blog will be used by System admins who will be using AIX in their work life. It can also be used for those newbies who want to get certifications in AIX Administration. This blog will be updated frequently to help the system admins and other new learners. DISCLAIMER: Please note that blog owner takes no responsibility of any kind for any type of data loss or damage by trying any of the command/method mentioned in this blog. You may use the commands/method/scripts on your own responsibility. If you find something useful, a comment would be appreciated to let other viewers also know that the solution/method work(ed) for you.

Monday, 9 September 2013

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
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