`<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>Hi guys,</p>
<p>Could you please give me some advise on the best way to increase
the capacity on my home server (running OmniOS obviously...)?</p>
<p>About four years ago I started designing and building my home
storage server based on a "Coolermaster Stacker" tower case by
retrofitting into it three Norco SS-500 and one SS-300 hotswap
modules, for a total of 18 hard drives.<br>
With this number of drive bays available, I choose to go for
RAIDZ2: three vdevs of six drives each. <br>
</p>
<p>Back in 2014, I started with only one vdev of six 4TB WD40EFRX
drives. About a year later, in early 2015, I put another six of
those drives in and expanded the pool. It has been humming happily
ever since. Awesome.</p>
<p>Over time however, the used pool capacity has now gone up to 86%.
It's time to expand again. <br>
I see a number of possible ways to do so:</p>
<ol>
<li>Get another six 4TB WD40EFRX's and fill the last open bays,
adding a 3rd vdev (capacity +50%).<br>
Pros: these drives are cheap nowadays, much cheaper than they
were three or four years ago.<br>
Cons: six extra spindles will increase electricity cost.<br>
</li>
<li>Get six 8TB WD80EFZX's and fill the last open bays, adding a
3rd vdev (capacity +100%).<br>
Pros: huge capacity increase.<br>
Cons: higher upgrade cost than option 1 (due to more expensive
drives). Six extra spindles will increase electricity cost.</li>
<li>Get six 8TB WD80EFZX's and *replace* the first vdev with
bigger disks (capacity +50%).<br>
Pros: amount of spindles doesn't change and thus electricity
cost will more or less remain the same. Replaced drives can be
utilized elsewhere, e.g. for offline pool-backups.<br>
Cons: higher upgrade cost than option 1 (due to more expensive
drives).</li>
</ol>
<p>The first question that comes to mind for option 2 and 3: are
there any disadvantages to creating a pool out of different
capacity drives? The drives per vdev are identical, it's just the
vdevs within the pool that aren't.</p>
<p>Right now I am leaning towards options 2 or 3, with maybe a
little preference for option 3, I think.<br>
</p>
<p>Any thoughts you guys can share on this matter? Would appreciate
it. Thanks!</p>
<p>Regards,</p>
<p>Andries<br>
</p>
</body>
</html>
`