HP P3410A - NetRAID 1M RAID Controller Installation And Configuration Manual page 44

Chapter 4
Logical Drives, RAID Levels, and Array Spanning
!
On Worksheet B, logical drives are numbered LD0 through LD39. For each
logical drive you plan to create, record the following information:
Array number to which the logical drive is assigned
Whether the logical drive spans up to eight sequentially numbered arrays
RAID level
For each logical drive, you also need to define the logical drive size (capacity),
stripe size, write policy, read policy, and cache policy as defined in the sections
that follow.
Logical Drive Size
!
You can calculate the usable capacity to assign to each logical drive, or you can
let the HP NetRAID Assistant Wizard specify it during configuration. If you
calculate logical drive capacity, record it in Worksheet B.
If you want a logical drive to occupy less space than is available on one array,
you must enter the logical drive size.
Stripe Size (Stripe Depth)
!
Stripe size is the amount of data contiguously written to each disk in an array. It
is sometimes called "stripe depth." You can specify stripe sizes 2 KB , 4 KB,
8 KB, 16 KB, 32 KB, 64 KB, and 128 KB for each logical drive. Consider the
following when setting your stripe size:
The default stripe size is 64 KB.
For best performance, choose a stripe size equal to or smaller than the
block size used by your operating system.
A large stripe size produces better performance if the system does mostly
sequential reads.
Choose a small stripe size if your system performs mostly random reads.
For each logical drive, log the stripe size in Worksheet B.
NOTE
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Consider the stripe size carefully, because once configured,
you cannot change the size.
Planning