HP Smart Array 5i and low write speed

[Arkadey Morozov]

I have HP ProLiant DL740 with RAID-contoller Smart Array 5i.
4 hard drives configuring in RAID5.
My problem - write speed in my logical drive 10-12 MB/sec.
Google suggests what need enable drivewritecache.
In config i see:

Cache Board Present: True
Cache Status: OK
Accelerator Ratio: 100% Read / 0% Write
Read Cache Size: 16 MB
Write Cache Size: 0 MB
Total Cache Size: 16 MB


Strangely, in boot controller firmware say "Smart Array 5i 32mb Cache".
From this info I understand what my controller support write cache?
So why can not I enable it?

=> ctrl slot=0 modify drivewritecache=enable forced

Error: This operation is not supported with the current configuration. Use the
"show" command on devices to show additional details about the
configuration.

=> ctrl slot=0 modify cacheratio=50/50

Error: "cacheratio=50/50" is not a valid option for Smart Array 5i in Slot 0

There are no options currently available.


My show config detail in attach file.

How to fix this problem, help please!

P.S. This thread ahs been moved from General to ProLiant Servers (ML,DL,SL). - Hp Forum moderator

[Sbrown]

• 233609-001 - 32MB Ultra3 Board.

• 260740-001 - 4.8V NiMH battery pack board - 360mAh, Battery Backed Write Cache (BBWC)

You don't appear to have the 32MB BATTERY BACKED WRITE CACHE Board. which may be why the cache is read-only 16MB