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<div class="moz-cite-prefix">On 01/02/13 02:58, Marcelo Pereira
wrote:<br>
</div>
<blockquote cite="mid:CD2FFEC6.12AF9%25marcelops@gmail.com"
type="cite">
<div>Hello Everyone,</div>
<div><br>
</div>
<div>I'm about to perform an upgrade on my servers and I was
wondering how to do that.</div>
<div><br>
</div>
<div>Here is the scenario:</div>
<div><br>
</div>
<div>Server A has 16x 1Tb hard drives, under RAID-6.</div>
<div>Server B has 16x 1Tb hard drives, under RAID-6.</div>
<div><br>
</div>
<div>And both are in sync, using DRBD.</div>
<div><br>
</div>
<div>I though about replacing the hard drives for 2Tb units, one
by one.</div>
<div><br>
</div>
<div>So, on each run, I would:</div>
<ul>
<li>Remove a 1Tb disk</li>
<li>Add a 2Tb disk</li>
<li>Wait for it to rebuild the RAID</li>
</ul>
<div>After replacing ALL disks, I would expand the RAID unit, on
each server.</div>
<div><br>
</div>
<div>However, I was wondering how DRBD would "like" this
procedure.</div>
<div><br>
</div>
<div>I know that, before "expanding" the RAID, the cluster size,
and the block numbers would remain the same, as I would be
"wasting" the extra space on the newly added drives.</div>
<div><br>
</div>
<div>So, after "both" servers have all the drives replaces, and
the RAID is properly rebuild. Would that be a problem to expand
it? How would DRBD handle it?</div>
<div><br>
</div>
<div>I will appreciate any comment or suggestion here.</div>
</blockquote>
DRBD will work perfectly...<br>
<br>
You probably need to do the following:<br>
1) Pull one drive and replace (you could do one on each server at
the same time, although better/safer to do one server at a time)<br>
2) Wait for rebuild to complete<br>
3) Repeat for all disks on BOTH servers<br>
4) Resize the RAID array on each server<br>
5) Resize DRBD (see the fantastic online manual for your version of
DRBD for the details)<br>
6) Resize the underlying filesystem or whatever<br>
<br>
BTW, depending on your kernel version, and/or RAID (I'm assuming
linux software raid), you might like to query the linux-raid list to
see if you can ADD the new drive, tell md that this new drive is
replacing drive X, this way you avoid degrading the RAID array,
hence lose less performance during the rebuild, and have a lower
risk of disk failure and especially URE (Unrecoverable Read Error)
during the rebuilds.<br>
<br>
Regards,<br>
Adam<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
Adam Goryachev
Website Managers
<a class="moz-txt-link-abbreviated" href="http://www.websitemanagers.com.au">www.websitemanagers.com.au</a>
</pre>
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