StorageWorks EK-SMRAB-IG, Руководство по установке

Страница: 55 / 84

EK–SMRAB–IG. B01 B–1
B
Configuration Guidelines
This appendix contains a list of guidelines that will assist in optimizing the performance of your RAID Array
310 Subsystem.
Use the following guidelines, as appropriate, to optimize you system performance.
1. Evenly distribute the devices across separate ports. This permits parallel activities on
the controller’s available ports to the attached devices.
2. Intermix higher and lower performance devices on the same port, that is, use 7200
rpm and 5400 rpm drives on the same port.
3. Evenly distribute logical units across separate targets, that is, use different SCSI IDs,
if possible. RAID Array 310 supports a maximum of four SCSI IDs.
4. Avoid configuring multiple mirrorsets with the first members being on the same
port. That is use:
add mirrorset m1 disk100 disk200
add mirrorset m2 disk210 disk110
Instead of using:
add mirrorset m1 disk100 disk200
add mirrorset m2 disk110 disk110
The default mirrorset read selection algorithm will choose the first member of the
mirrorset if the mirrorset does not already have a read queue.
5. If write performance is important, the writeback cache should be turned ON for each
unit. The default value is OFF.
6. If transfer sizes are small (less than 8 KB), use the default maxi-
mum_cached_transfer size (32). Transfers that exceed the default maxi-
mum_cached_transfer size will never go into the cache. For most random access
benchmarks, it is best to set this number high (for example, 1024).