Silicon Graphics InfiniteStorage 6120, Руководство пользователя

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Configuring the InfiniteStorage 6120
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2.3.7 Creating Storage Pools
A storage pool on a InfiniteStorage 6120 has the following attributes:
• RAID level
Storage pools can be configured to use either a RAID5 or RAID6 parity scheme. In RAID5, the
capacity of one drive is reserved for parity, allowing data recovery in the event of a single drive
loss in the storage pool. In RAID6, the capacity of two drives is reserved for parity, allowing
data recovery if either one or two drives are down in a storage pool.
For maximum data
protection, SGI recommends the use of RAID6 .
• Chunk size
The chunk size defines the amount of data written to a single disk before proceeding to the next
disk in the storage pool. For optimal performance, the chunk size should be proportional to the
expected host request size. For example, a large chunk size should be used when transferring
large blocks of data while a small chunk size should be used when transferring multiple small
blocks of data.
• Drive count
A RAID5 storage pool may consist of 5 or 9 drives. A RAID6 storage pool may consist of 6 or
10 drives. For maximum performance, storage pools should be created using drives with the
same characteristics (such as SAS/SATA, capacity, and RPM).
Note : SGI does not support the mixing of SAS and SATA drives in the same storage pool.
To create a storage pool, use the CREATE POOL command:
1. At the CLUI prompt, type:
CREATE POOL RAID_LEVEL=<RAID level> CHUNK_SIZE=<chunk size>
{ASSIGN_POLICY=[SAS|SATA] NUMBER=<number of disks> or
PHYSICAL_DISK=<list of disks>}
where <RAID level>= raid5 or raid6; <chunk_size>=64kb, 128kb, or 256kb; <number of
disks>= 5 or 9 drives for RAID 5, 6 or 10 drives for RAID 6; <list of disks>=index name of
disks.
You may either explicitly select the disks for the pool by using PHYSICAL_DISK= or specify
the number of disks in the pool by using NUMBER= in which case the next available disks will
be selected
(Figure 30)
.
If you specify the
ASSIGN_POLICY
and
NUMBER
parameters together
(Figure 31)
, only the
selected type of drives will be used for the storage pool and you will not need to enter the
individual disk name.
2. Use the CREATE POOL command to add more storage pools as needed. If you need to delete a
storage pool, use the DELETE POOL <pool-id> command.
Figure 30. CREATE POOL Example (1)
RAID$ create pool raid_level=raid5 chunk_size=64kb physical_disk=0x003e 0x003f
POOL 0 OID=0x19b60000 create STATUS='Success' (0x0)
RAID$ create pool raid_level=raid6 chunk_size=128kb number=6
POOL 1 OID=0x19b80001 create STATUS='Success' (0x0)
0x0040 0x0041 0x0042
Figure 31. CREATE POOL Example (2)
RAID$ create pool raid_level=raid6 chunk_size=128kb number=6 assign_policy=sas
POOL 2 OID=0x19b80002 create STATUS='Success' (0x0)