On 12/1/2010 7:54 AM, Kevin Grittner wrote: <blockquote cite="mid:4CF61B430200002500038009@gw.wicourts.gov"
type="cite"><br/><pre wrap="">
Your RAID configuration and controllers will likely make a bigger
difference than your filesystem choices. Be sure to get good RAID
controllers with battery-backed (BBU) cache, configured for
write-back.
</pre></blockquote> I agree that storage makes a bigger difference than filesystems in most cases.<br /> Just wanted to
jumpin and say that testing with your workload is really the only way to know things for sure. (Obviously, more
spindlesimplies more IOps, more cache implies faster writes...)<br /> But I have seen cases where a dell PERC RAID
controller(not sure that qualifies as "good") slowed things down when configured for writeback with a write heavy
workload.We noticed very spiky disk IO rates on some database servers (we are monitoring company, so have lots and lots
ofpretty graphs.) The controller seemed to accept a bunch of writes quickly, then when full then try to pump them all
todisk, which took a non-trivial number of seconds. So we'd see the interesting state of iostat reporting zero disk
transactionsper second, but busy time = 100% and service time being hundreds of millseconds.<br /> Switching to write
throughmade things much faster overall. Not what I expected.<br /><br /> This was a PERC 5, so a few years ago. No
doubtthings have improved, but the point is to test and monitor.<br /><br /><div class="moz-signature">-- <br /><style
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</style><divclass="sig"><table class="border"><tbody><tr><td class="back"> <b>Steve Francis</b></td><td class="back"
style="width:30px;"><br /></td><td class="back" style="text-align: right;"><b>LogicMonitor LLC</b></td></tr><tr><td><br
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target="_blank">www.logicmonitor.com</a></td><td><br/></td><td class="bottom" style="text-align: right;"> Ph: 1 888 41
LOGICx500<br /> Ph: 1 805 698 0770</td></tr></tbody></table><p> <br /></div></div>
