Different performance profiles even though they may support the same specs, and also the fact that even drives of the same size may not necessarily have the same physical geometries or other physical characteristics. e.g., different cache sizes - on a mirrored drive maybe one drive has to do a cache flush while another one doesn't, thus causing the write to take longer simply because one drive could absorb the write without going to the platters while the other couldn't. That's assuming you didn't match cache sizes, which most people likely would have the sense to not do even if they were mixing/matching drives/vendors. <br>
<br>My experience in large-enterprise installs is that everyone uses the same drives within their arrays and disk cabinets. We didn't experience massive simultaneous failures, and the detection/replacement of failed drives was just part of the service contract for the hardware. Originally we would replace failed drives and rebuild arrays ourselves, but over the past eight years the vendors took that over. <br>
<br>Lastly, diversifying drive as a risk-mitigation strategy can have the opposite effect - one of the mix-in products may be far worse than the others. <br><br>-Rob<br><br><br><div class="gmail_quote">On Sun, Aug 15, 2010 at 7:03 AM, Jeremy MountainJohnson <span dir="ltr"><<a href="mailto:jeremy@jskier.com">jeremy@jskier.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Arguably the problem is they will have differing performance albeit<br>
the same specs. Does this matter in the grand scheme of things for<br>
most RAID environments? I wouldn't think so. I've seen RAID1 setups<br>
failing at the same time with the same drives installed- problem is if<br>
you buy from the same place you're pulling from the same batch, at<br>
minimal one should mix it up to some extent.<br>
<font color="#888888"><br>
Jeremy MountainJohnson<br>
<a href="mailto:jeremy@jskier.com">jeremy@jskier.com</a><br>
</font><div><div></div><div class="h5"><br>
<br>
<br>
On Sun, Aug 15, 2010 at 12:36 AM, Mike Miller <<a href="mailto:mbmiller%2Bl@gmail.com">mbmiller+l@gmail.com</a>> wrote:<br>
><br>
> On Sat, 14 Aug 2010, Robert Nesius wrote:<br>
><br>
> > Don't think I'd ever mix drive manufacturer's in any RAID configuration,<br>
> > myself. That seems to go against the grain. But maybe my notions on<br>
> > that point are out-dated. Anyone else have opinions on that?<br>
><br>
> Someone once told me that he thought it was better to mix them because it<br>
> would be less likely that several would fail at nearly the same time.<br>
> That makes sense. What would be the problem with mixing? In what sense<br>
> does that go against the grain?<br>
><br>
> Mike<br>
><br>
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