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<div class="moz-cite-prefix">it is time for me to move my MDS to a
diferent HW infrastructure.</div>
<div class="moz-cite-prefix">So I Was wondering if the following
procedure can work.</div>
<div class="moz-cite-prefix">I have mds1 (old mds) and mds2 (new
mds). On the old mds I have a zfs MGS partition and a zfs MDT
partition.<br>
</div>
<div class="moz-cite-prefix">
<ul>
<li>create a new ZFS MGS and MDT partition on mds2 and create a
lustre FS on it</li>
<li>umount lustre on mds2<br>
</li>
<li>stop all the OSSes belonging to mds1 and stop and umount
lustre on mds1</li>
<li>zfs send the MGS partition from mds1 and zfs receive it on
mds2</li>
<li>zfs send the MGT partition from mds1 and zfs receive it on
mds2</li>
<li>mount lustre on mds2</li>
</ul>
<p>should it work ?</p>
<p>thanks</p>
<p>Rick</p>
<p><br>
</p>
</div>
<div class="moz-cite-prefix">On 8/23/18 2:40 PM, Mohr Jr, Richard
Frank (Rick Mohr) wrote:<br>
</div>
<blockquote type="cite"
cite="mid:C958EB45-9EFF-4D96-B2DE-D5AC9D3BEFDC@utk.edu">
<pre class="moz-quote-pre" wrap="">
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">On Aug 22, 2018, at 8:10 PM, Riccardo Veraldi <a class="moz-txt-link-rfc2396E" href="mailto:Riccardo.Veraldi@cnaf.infn.it"><Riccardo.Veraldi@cnaf.infn.it></a> wrote:
On 8/22/18 3:13 PM, Mohr Jr, Richard Frank (Rick Mohr) wrote:
</pre>
<blockquote type="cite">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">On Aug 22, 2018, at 3:31 PM, Riccardo Veraldi <a class="moz-txt-link-rfc2396E" href="mailto:Riccardo.Veraldi@cnaf.infn.it"><Riccardo.Veraldi@cnaf.infn.it></a> wrote:
I would like to migrate this virtual machine to another infrastructure. it is not simple because the other infrastructure is vmware.
what is the best way to migrate those partitions without incurring into any corruption of data ?
May I simply use zfs send and zfs receive thru SSH ?
what is the best way to move a MDS based virtual machine ?
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">I don’t have much experience with VMs, but I have used zfs send/receive to migrate a MDT from one server to another. It worked quite well.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">that's encouraging. it should work for VM too then regardless.
I have many MDSes as virtual machines. I found it to be a good way for high availability, they perform well enough.
so what you do is to shut down lustre on OSSes and MDS. At this point you simply zfs send and zfs receive on the new MDS ?
once the operation is terminated the new MDS is just ready to be used ?
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
It is possible to take snapshots on the current MDT and do incremental send/receives to the new MDT while the system is still up and running. When you are ready to switch over, then you shutdown the file system, do a final send/receive, and then start the new MDS. The new MDS will need to have the same configuration (NID, etc.) as the old MDS (unless you want to perform a writeconf).
There was a talk at LUG in 2017 from someone who did something similar with OSTs:
<a class="moz-txt-link-freetext" href="http://cdn.opensfs.org/wp-content/uploads/2017/06/Wed06-CroweTom-lug17-ost_data_migration_using_ZFS.pdf">http://cdn.opensfs.org/wp-content/uploads/2017/06/Wed06-CroweTom-lug17-ost_data_migration_using_ZFS.pdf</a>
That should give you a good idea of how to proceed.
--
Rick Mohr
Senior HPC System Administrator
National Institute for Computational Sciences
<a class="moz-txt-link-freetext" href="http://www.nics.tennessee.edu">http://www.nics.tennessee.edu</a>
</pre>
</blockquote>
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