I would split the load to both heads. What&#39;s the point in spending all the money for two heads if you are only going to use one...?<div>4 shelves of DS4243 will perform extremely well. I saw it on my own 3170, 6070, and 6080 pairs.</div>

<div><br></div><div>I would likely create one large aggr on each head (pending the environment...not knowing yours) and then create the volumes on that.</div><div>I would also split the DS14mk4 shelves between the heads as well....personally, I would turn off the disk-auto-assign and assign them myself</div>

<div>since the systems use software ownership, I can give a half shelf to one head and the other half to the other head.</div><div><br clear="all">--tmac<br>         Tim McCarthy<br>     Principal Consultant<br><br>  RedHat Certified Engineer<br>

   804006984323821 (RHEL4)<br>   805007643429572 (RHEL5)<br>
<br><br><div class="gmail_quote">On Thu, Nov 3, 2011 at 4:11 PM, Fletcher Cocquyt <span dir="ltr">&lt;<a href="mailto:fcocquyt@stanford.edu">fcocquyt@stanford.edu</a>&gt;</span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">

<div style="word-wrap:break-word">Fellow toasters,<div>we are trading up some old trays for new DS4243 trays and we are trying to decide if we allocate all 8 of our DS4243 trays to one ~40Tb aggregate (we plan to run ONTAP 8.1 for data motion) assigned to one of the cluster&#39;s heads will the advantage of all those spindles in one aggr be killed by the head being overloaded?</div>

<div>In which case would we be better served by 2 x 4  DS4243 AGGRs - one assigned to each 3270 head?</div><div><br></div><div>We also have 7 DS14-MK4 shelves to help balance out the workloads</div><div><br></div><div>All other things equal - I&#39;m inclined to go for the one big 40Tb aggr vs 2 x 20Tb aggrs to reap the biggest IO capacity and performance</div>

<div>Currently our CPU weekly average workloads on the two 3270 heads are only 20% and 16%</div><div><br></div><div>My impression is a single 3270s head should be have enough headroom to push the large aggr to its full IO capacity.</div>

<div>But I&#39;d be very interested to hear the advice others who have tested both options and any unforeseen issues with an aggr this large (our previous largest is 16Tb under 7.3.5.1P2)</div><div><br></div><div>thanks</div>

<span class="HOEnZb"><font color="#888888"><div><br></div><div>Fletcher.</div><div><div><span style="border-collapse:separate;color:rgb(0, 0, 0);font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:-webkit-auto;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="border-collapse:separate;color:rgb(0, 0, 0);font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:-webkit-auto;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="border-collapse:separate;color:rgb(0, 0, 0);font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:-webkit-auto;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="border-collapse:separate;color:rgb(0, 0, 0);font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:-webkit-auto;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><span style="border-collapse:separate;color:rgb(0, 0, 0);font-style:normal;font-variant:normal;font-weight:normal;letter-spacing:normal;line-height:normal;text-align:-webkit-auto;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><div>

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