<div dir="ltr"><div>Thank you Ramon for your answer.</div><div><br></div><div>The only thing I can't understand is why to use such a big shard?</div><div></div><div>The default is 64MB. I thought maybe to decrease it, I wanted to do some tests on it.</div><div><br></div><div>Best regards,<br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Il giorno ven 6 set 2019 alle ore 23:09 Ramon Selga <<a href="mailto:ramon.selga@gmail.com">ramon.selga@gmail.com</a>> ha scritto:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<div class="gmail-m_-5423031927693632057moz-cite-prefix">Hi Cristian,<br>
<br>
Both approaches are correct but they have different usable
capacity and tolerance to node failures.<br>
<br>
First one is a full replica 3 meaning you get your total node
capacity divided by 3, because replica 3, and it tolerates a
simultaneous of two nodes and very good for split-brain avoidance.<br>
<br>
Second one is a replica 2 with arbiter, also very good for
split-brain avoidance (that's purpose of arbiter bricks). In this
case you get your total capacity divided by two except a little
space going to arbiter-bricks, may be less than 1% of normal
storage bricks. It tolerates one node failure at the same time.<br>
<br>
For VM usage remember to enable sharding with a shard size of
256MB at least before use volume.<br>
<br>
If efficiency between total and usable capacity is a concern for
you and you think you could tolerate only one node failure at the
same time, may I suggest you to use a distributed dispersed 3
redundancy 1 volume?. You will get your total capacity divided by
3 times 2 (that's 2/3 of total capacity) and this config still
tolerates one node failure at the same time.<br>
<br>
Hope this helps.<br>
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El 06/09/19 a les 17:11, Cristian Del Carlo ha escrit:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Hi,<br>
<br>
I have an environment consisting of 4 nodes ( with large disks).<br>
I have to create a volume to contain image of virtual machines.<br>
<br>
In documentation i read:<br>
<i>Hosting virtual machine images requires the consistency of
three-way replication, <br>
which is provided by three-way replicated volumes, three-way
distributed replicated volumes, <br>
arbitrated replicated volumes, and distributed arbitrated
replicated volumes. </i><br>
<br>
So I'm going to confusion to configure this volume.<br>
I have 4 nodes and I don't want to lose space by dedicating one
to the function of arbiter.<br>
<br>
Would it be reasonable to configure the volume as in these two
examples?
<div><br>
</div>
<div># gluster volume create test1 replica 3 \<br>
server1:/bricks/brick1 server2:/bricks/brick1
server3:/bricks/brick1 \<br>
server2:/bricks/brick2 server3:/bricks/brick2
server4:/bricks/brick2 \<br>
server3:/bricks/brick3 server4:/bricks/brick3
server1:/bricks/brick3 \<br>
server4:/bricks/brick4 server1:/bricks/brick4
server2:/bricks/brick4 <br>
</div>
<div><br>
</div>
<div># gluster volume create test1 replica 3 arbiter 1 \<br>
server1:/bricks/brick1 server2:/bricks/brick1
server3:/bricks/arbiter_brick1 \<br>
server2:/bricks/brick2 server3:/bricks/brick2
server4:/bricks/arbiter_brick2 \<br>
server3:/bricks/brick3 server4:/bricks/brick3
server1:/bricks/arbiter_brick3 \<br>
server4:/bricks/brick4 server1:/bricks/brick4
server2:/bricks/arbiter_brick4 </div>
<div><br>
</div>
<div>Thanks,</div>
<div><br>
</div>
<div>-- <br>
<div dir="ltr" class="gmail-m_-5423031927693632057gmail_signature">
<div dir="ltr">
<div><span></span><span></span><br>
</div>
<div><font><b><font color="#990000"><i><br>
</i></font></b></font></div>
<div><font><b><font color="#990000"><i>Cristian Del Carlo</i></font></b><br>
</font></div>
<br>
</div>
</div>
</div>
</div>
<br>
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