RAID 0 => Plain striping typically with 24kb, 54kb or 128kb stripe size
RAID 1 => Mirroring
RAID 5 => Stripping with parity
2) Describe in brief the composition of FC Frame?
Start of the Frame locator
Frame header (includes destination id and source id, 24 bytes/6 words)
Data Payload (encapsulate SCSI instruction can be 0-2112 bytes in length)
CRC (error checking, 4 bytes)
End of Frame (1 byte)
3) What is storage virtualization?
Storage virtualization is amalgamation of multiple n/w storage devices into single storage unit.
4) What are the protocols used in physical/datalink and network layer of SAN?
a) Ethernet
b) SCSI
c) Fibre Channel
5) What are the types of disk array used in SAN?
a) JBOD
b) RAID
6) What are different types of protocols used in transportation and session layers of SAN?
a) Fibre Channel Protocol (FCP)
b) Internet SCSI (iSCSI)
c) Fibre Channel IP (FCIP)
7) What is the type of Encoding used in Fibre Channel?
8b/10b, as the encoding technique is able to detect all most all the bit errors
8) How many classes of service are available in Fibre Channel?
7 Classes of service
9) What are the main constrains of SCSI in storage networking?
a) Deployment distance (max. of 25 mts)
b) Number of devices that can be interconnected (16)
10) What is a Fabric?
Interconnection of Fibre Channel Switches
11) What are the services provided by Fabric to all the nodes?
a) Fabric Login
b) SNS
c) Fabric Address Notification
d) Registered state change notification
e) Broadcast Servers
12) What is the difference between LUN and WWN?
LUN: unique number that is assigned to each storage device or partition of the storage that the storage can support.
WWN: 64bit address that is hard coded into a fibre channel HBA and this is used to identify individual port (N_Port or F_Port) in the fabric.
13) What are the different topologies in Fibre Channel?
a) Point-to-Point
b) Arbitrary Loop
c) Switched Fabric Loop
14) What are the layers of Fibre Channel Protocol?
a) FC Physical Media
b) FC Encoder and Decoder
c) FC Framing and Flow control
d) FC Common Services
e) FC Upper Level Protocol Mapping
15) What is zoning?
Fabric management service that can be used to create logical subsets of devices within a SAN. This enables portioning of resources for management and access control purpose.
16) What are the two major classification of zoning?
Two types of zoning are
a) Software Zoning
b) Hardware Zoning
17) What are different levels of zoning?
a) Port Level zoning
b) WWN Level zoning
c) Device Level zoning
d) Protocol Level zoning
e) LUN Level zoning
18) What are the 3 prominent characteristics of SAS Protocol?
a) Native Command Queuing (NCQ)
b) Port Multiplier
c) Port Selector
19) What are the 5 states of Arbitrary Loop in FC?
a) Loop Initialization
b) Loop Monitoring
c) Loop arbitration
d) Open Loop
e) Close Loop
20) How does FC Switch maintain the addresses?
FC Switch uses simple name server to maintain the mapping table
a) Linear Recording
b) Helical Scan Recording.
32) What is snap shot?
A snapshot of data object contains an image of data at a particular point of time.
33) What is HSM?
Hierarchical storage management, an application that attempts to match the priority of data with the cost of storage.
34) What is hot-swapping?
Devices are allowed to be removed and inserted into a system without turning off the system.
35) What is Hot-Sparing?
A spare device is available to be inserted into the subsystem operation without having to remove and replace a device.
36) What are different types of backup system?
a) Offline
b) Online
c) Near Line
37) What is the different between mirroring, Routing and multipathing?
Redundancy Functions Relationships Role
Mirroring Generates 2 i/os to 2 storage targets Creates 2 copies of data
Routing Determined by switches independent of SCSI Recreates n/w route after a failure
Multipathing Two initiator to one target Selects the LUN initiator pair to use
38) Name few types of Tape storage?
a) Digital Linear Tape
b) Advanced Intelligent Tape
c) Linear Tape Open
39) What is a sequence in FC?
Group of one or more frames that encompasses one or more “information units” of a upper layer protocol.
Example:
It requires
i) One sequence to transfer the command
ii) One or more sequence to transfer the data
iii) Once sequence to transfer the status.
40) What is Exchange in FC?
Exchange is to establish a relationship between 2 N_PORTs and then these two ports transfer data via one or more sequence within this relationship.
Example: Exchange exist to transfer the command, data and the status of one SCSI task
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