<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>On 4/9/20 12:47 PM, Strahil Nikolov wrote:
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">On April 9, 2020 5:16:47 PM GMT+03:00, Valerio Luccio <a class="moz-txt-link-rfc2396E" href="mailto:valerio.luccio@nyu.edu"><valerio.luccio@nyu.edu></a> wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Hi,
I'm afraid I still need some help.
When I originally set up my gluster (about 3 years ago), I set it up as
Distributed-Replicated without specifying a replica count and I believe
that defaulted to a replica 2. I have 4 servers with 3 RAIDs attached
to
each server. This was my result:
Number of Bricks: 6 x 2 = 12
Transport-type: tcp
Bricks:
Brick1: hydra1:/gluster1/data
Brick2: hydra1:/gluster2/data
Brick3: hydra1:/gluster3/data
Brick4: hydra2:/gluster1/data
Brick5: hydra2:/gluster2/data
Brick6: hydra2:/gluster3/data
Brick7: hydra3:/gluster1/data
Brick8: hydra3:/gluster2/data
Brick9: hydra3:/gluster3/data
Brick10: hydra4:/gluster1/data
Brick11: hydra4:/gluster2/data
Brick12: hydra4:/gluster3/data
If I understand this correctly I have 6 sub-volumes with Brick2 replica
of Brick1, Brick4 of Brick3, etc. Correct ?
I realize now that it would probably have been better to specify a
different order, but now I cannot change it.
Now I want to store oVirt images on the Gluster and it requires either
replica 1 or replica 3. I need to be able to reuse the bricks I have
and
was planning to remove some bricks, initialize them and add them back
as
a replica 3.
Am I supposed to remove 6 bricks, one from each sub-volume ? Will that
work ? Will I lose storage space ? Can I just remove a brick from each
server and use those for the replica 3 ?
Thanks for all the help.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
Hi Valerio,
You can find a small system and make it an arbiter , so you will end up with 'replica 3 arbiter 1' .
The arbiter storage calculation is that you need 4K for each file in the volume.If you don't know them the general rule of thumb is your arbiter brick be 1/1024 the size of the data brick.
Keep in mind that it will be better if your arbiter has an SSD (for example mounted on /gluster) from which you can create 6 directories.The arbiter stores only metadata and the SSD random access performance will be the optimal approach.
Something like:
arbiter:/gluster/data1
arbiter:/gluster/data2
arbiter:/gluster/data3
arbiter:/gluster/data4
arbiter:/gluster/data5
arbiter:/gluster/data6
Of course , proper testing on a test volume is a good approach before implementing on prod.
Best Regards,
Strahil Nikolov
</pre>
</blockquote>
</p>
<p>Thanks,</p>
<p>that sounds like a great idea.<br>
</p>
<div class="moz-signature">-- <br>
<table bordersize="0" cellspacing="0" cellpadding="0">
<tbody>
<tr>
<td>As a result of Coronavirus-related precautions, NYU and
the Center for Brain Imaging operations will be managed
remotely until further notice.</td>
</tr>
<tr>
<td>All telephone calls and e-mail correspondence are being
monitored remotely during our normal business hours of
9am-5pm, Monday through Friday.</td>
</tr>
<tr>
<td> </td>
</tr>
<tr>
<td>For MRI scanner-related emergency, please contact: Keith
Sanzenbach at <a class="moz-txt-link-abbreviated" href="mailto:keith.sanzenbach@nyu.edu">keith.sanzenbach@nyu.edu</a> and/or Pablo
Velasco at <a class="moz-txt-link-abbreviated" href="mailto:pablo.velasco@nyu.edu">pablo.velasco@nyu.edu</a></td>
</tr>
<tr>
<td>For computer/hardware/software emergency, please
contact: Valerio Luccio at <a class="moz-txt-link-abbreviated" href="mailto:valerio.luccio@nyu.edu">valerio.luccio@nyu.edu</a></td>
</tr>
<tr>
<td>For TMS/EEG-related emergency, please contact: Chrysa
Papadaniil at <a class="moz-txt-link-abbreviated" href="mailto:chrysa@nyu.edu">chrysa@nyu.edu</a></td>
</tr>
<tr>
<td>For CBI-related administrative emergency, please
contact: Jennifer Mangan at <a class="moz-txt-link-abbreviated" href="mailto:jennifer.mangan@nyu.edu">jennifer.mangan@nyu.edu</a></td>
</tr>
</tbody>
</table>
<p>
</p>
<table style="color:gray" bordersize="0" cellspacing="0"
cellpadding="0">
<tbody>
<tr>
<td>Valerio Luccio</td>
<td> </td>
<td>(212) 998-8736</td>
</tr>
<tr>
<td>Center for Brain Imaging</td>
<td> </td>
<td>4 Washington Place, Room 158</td>
</tr>
<tr>
<td>New York University</td>
<td> </td>
<td>New York, NY 10003</td>
</tr>
</tbody>
</table>
<p>
</p>
<blockquote>"In an open world, who needs windows or gates ?"</blockquote>
</div>
</body>
</html>