IBM Netfinity ServeRAID-4H Ultra160, Справочник пользователя

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Create an array using all four physical
drives.
Then, create a logical drive (labeled
as 1) within the array.
Notice that the distributed spare drive
is the free space (labeled as 2) shown
below the logical drive.
2
1
The data is striped across the drives,
creating blocks in the logical drive.
The storage of the data parity
(denoted by
*
) is striped, and it shifts
from drive to drive as it does in RAID
level-5.
Notice that the spare drive is not
striped.
5
7
1
*
*
2
6
8
4
*
3
9
If a physical drive fails in the array,
the data from the failed drive is
compressed into the distributed spare
drive. The logical drive remains RAID
level-5E.
When you replace the failed drive, the
data for the logical drive
decompresses and returns to the
original striping scheme.
9
3
5
7
1
*
*
*
*
2
6
8
4
*
Note: The ServeRAID Manager program Express configuration does not default to
RAID level-5E. If you have four physical drives, Express configuration
defaults to RAID level-5 with a hot-spare drive.
Understanding RAID level-x0
RAID level-x0 refers to RAID levels-00, 10, 1E0, and 50. RAID level-x0 includes
more physical drives in an array. The benefits of doing so are larger logical drives,
increased performance, and increased reliability. RAID levels-0, 1, 1E, 5, and 5E
cannot use more than 16 physical drives in an array. However, RAID levels-00, 10,
1E0, and 50 include more physical drives by managing an array of arrays, or a
spanned array. The operating system uses the spanned array logical drive the
same as a regular array logical drive.
Note: RAID level-x0 is only available on the IBM ServeRAID-4H Ultra160 SCSI
controller.
RAID level-x0 requires a minimum of 2 drives and supports a maximum of 60
drives.
8
IBM
®
Netfinity
®
User’s Reference: ServeRAID
™
-4H Ultra160 SCSI Controller