On Thu, Jan 24, 2013 at 12:22 PM, Blake Hudson <blake@xxxxxxxx> wrote:
Thanks for this tip. It put me on to what is wrong.
Jan 18 07:25:39 myserv Server Administrator: Storage Service EventID: 2335 Controller event log: BBU disabled; changing WB virtual disks to WT: Controller 0 (PERC 5/i Integrated)
Bingo! We had write back all along, and the performance tanked when it
fell back to write through. I was wondering why my policy change attempts
were flipping back when I tried testing WB this morning!
This explains everything we've been seeing. Wow. Gotta call Dell.
Thanks everyone for the assistance. I didn't think a battery which shows OK
status in omreport could wound us!
There are a couple suggestions I'd like to put forth. First, improper
partition alignment is generally masked by the controller cache. I
strongly encourage you to check that your RAID array is making use of
this cache by enabling the WriteBack caching option on this array,
especially if your PERC card has a BBU (I think this was optional on
perc 5). You can install the MegaCLI tool from LSI to verify this (can
also be checked from OpenManage or reboot into the controller BIOS).
Thanks for this tip. It put me on to what is wrong.
Jan 18 07:25:39 myserv Server Administrator: Storage Service EventID: 2335 Controller event log: BBU disabled; changing WB virtual disks to WT: Controller 0 (PERC 5/i Integrated)
Bingo! We had write back all along, and the performance tanked when it
fell back to write through. I was wondering why my policy change attempts
were flipping back when I tried testing WB this morning!
This explains everything we've been seeing. Wow. Gotta call Dell.
Thanks everyone for the assistance. I didn't think a battery which shows OK
status in omreport could wound us!
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