`<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Jan 19, 2015, at 3:55 AM, Rune Tipsmark <<a href="mailto:rt@steait.net" class="">rt@steait.net</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
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<div dir="ltr" style="font-size: 12pt; background-color: rgb(255, 255, 255); font-family: Calibri, Arial, Helvetica, sans-serif;" class=""><p class="">hi all,</p><div class=""> <br class="webkit-block-placeholder"></div><p class="">just in case there are other people out there using their ZFS box against vSphere 5.1 or later... I found my storage vmotion were slow... really slow... not much info available and so after a while of trial and error I found a nice combo that works very
well in terms of performance, latency as well as throughput and storage vMotion.</p><div class=""> <br class="webkit-block-placeholder"></div><p class="">- <strong class="">Use</strong><strong class=""> ZFS volumes</strong> instead of thin provisioned LU's - Volumes support two of the VAAI features</p><div class=""><br class=""></div></div></div></blockquote><div><br class=""></div>AFAIK, ZFS is not available in VMware. Do you mean run iSCSI to connect the ESX box to</div><div>the server running ZFS? If so...<br class=""><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" style="font-size: 12pt; background-color: rgb(255, 255, 255); font-family: Calibri, Arial, Helvetica, sans-serif;" class=""><p class="">- <strong class="">Use thick provisioning disks</strong>, lazy zeroed disks in my case <strong class="">
reduced storage vMotion by 90%</strong> or so - machine 1 dropped from 8½ minutes to 23 seconds and machine 2 dropped from ~7 minutes to 54 seconds... a rather nice improvement simply by changing from thin to thick provisioning.</p><div class=""><br class=""></div></div></div></blockquote><div><br class=""></div>This makes no difference in ZFS. The "thick provisioned" volume is simply a volume with a reservation.</div><div>All allocations are copy-on-write. So the only difference between a "thick" and "thin" volume occurs when</div><div>you run out of space in the pool.<br class=""><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" style="font-size: 12pt; background-color: rgb(255, 255, 255); font-family: Calibri, Arial, Helvetica, sans-serif;" class=""><p class="">- I dropped my Qlogic HBA <strong class="">max queue depth from default 64 to 16</strong> on all ESXi hosts and now I see an average latency of less than 1ms per data store (on 8G fibre channel). Of course there are spikes when doing storage vMotion at these speeds
but its well worth it.</p><div class=""><br class=""></div></div></div></blockquote><div><br class=""></div><div>I usually see storage vmotion running at wire speed for well configured systems. When you get </div><div>into the 2GByte/sec range this can get tricky, because maintaining that flow through the RAM</div><div>and disks requires nontrivial amounts of hardware.</div><div><br class=""></div><div>More likely, you're seeing the effects of caching, which is very useful for storage vmotion and</div><div>allows you to hit line rate.</div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" style="font-size: 12pt; background-color: rgb(255, 255, 255); font-family: Calibri, Arial, Helvetica, sans-serif;" class=""><div class=""> <br class="webkit-block-placeholder"></div><p class="">I am getting to the point where I am almost happy with my ZFS backend for vSphere.</p><div class=""><br class=""></div></div></div></blockquote><div><br class=""></div><div>excellent!</div><div> -- richard</div><div><br class=""></div></div><br class=""></body></html>`