<br><div class="gmail_quote">On Thu, Jan 24, 2013 at 12:22 PM, Blake Hudson <span dir="ltr"><<a href="mailto:blake@ispn.net" target="_blank">blake@ispn.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="HOEnZb"><div class="h5"><br>
<br>
</div></div>There are a couple suggestions I'd like to put forth. First, improper<br>
partition alignment is generally masked by the controller cache. I<br>
strongly encourage you to check that your RAID array is making use of<br>
this cache by enabling the WriteBack caching option on this array,<br>
especially if your PERC card has a BBU (I think this was optional on<br>
perc 5). You can install the MegaCLI tool from LSI to verify this (can<br>
also be checked from OpenManage or reboot into the controller BIOS).<br>
<br></blockquote><div><br>Thanks for this tip. It put me on to what is wrong.<br><br>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) <br>
<br>Bingo! We had write back all along, and the performance tanked when it<br>fell back to write through. I was wondering why my policy change attempts<br>were flipping back when I tried testing WB this morning!<br><br>
This explains everything we've been seeing. Wow. Gotta call Dell.<br><br>Thanks everyone for the assistance. I didn't think a battery which shows OK<br>status in omreport could wound us!<br><br></div></div><br>