<div>I personally would recommend against RAID5 unless in the most dire circumstance. Raid 5 performance, especially software raid 5, is brutal.</div>
<div><br>If it all possible, I recommend raid 10/0+1 or just simply raid 1.<br><br> </div>
<div><span class="gmail_quote">On 8/9/06, <b class="gmail_sendername">Lars Ellenberg</b> <<a href="mailto:Lars.Ellenberg@linbit.com">Lars.Ellenberg@linbit.com</a>> wrote:</span>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">/ 2006-08-09 13:53:39 -0600<br>\ Monty Taylor:<br>> No, it's an internal LSI MegaRAID configured in Raid5. (not my choice)
<br>><br>> On the positive side, though, it supports 90M/sec of reading.<br><br>if it is an option, try to put it into jbod,<br>then do software raid5 on those.<br>should help if that controller is "CPU" bound,
<br>and your file server is not...<br><br>and, btw, you probably know that already ...<br>raid controllers tend to pretend against the kernel that data was<br>on stable storage, even when they indeed only have it still in their
<br>write back cache.<br>if that cache is battery backed, ok.<br>if not, and you get data corruption after blackout/brownout,<br>don't blame linux, nor the device/file system drivers,<br>nor drbd either...<br><br>unfortunately sometimes you can not put it in "write through" mode
<br>(use that cache, but only say its done when its really done), but<br>only switch off the cache completely.<br>and then your write throughput gets really bad...<br><br>so you better make sure you run on some ups, and monitor it,
<br>and power down the box cleanly in case the ups capacity runs out.<br><br>--<br>: Lars Ellenberg Tel +43-1-8178292-0 :<br>: LINBIT Information Technologies GmbH Fax +43-1-8178292-82 :
<br>: Schoenbrunner Str. 244, A-1120 Vienna/Europe <a href="http://www.linbit.com">http://www.linbit.com</a> :<br>__<br>please use the "List-Reply" function of your email client.<br>_______________________________________________
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<br></blockquote></div><br><br clear="all"><br>-- <br>"Do the actors on Unsolved Mysteries ever get arrested because they look just like the criminal they are playing?"<br><br>Christopher<br>