<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p>Hello Rudi</p>
<p>If you have a 4th server it may work,but I am not knowledgeable
about Gluster's GEOreplication. Perhaps someone else can advise.</p>
<p>With regards RAID 5 for 4 disks this is intended for capacity and
as mentioned 4 disks is the maximum I would use for RAID5. As you
have SSDs and intend to use a caching technique like bcache ou
dm-cache this should cover the performance hit of RAID 5 write.<br>
If you consider using RAID 6 in only 4 disks you are much better
of using RAID 10 then as you will have double write performance
and same capacity. I normally use RAID 10 or in ZFS configurations
(not this case) multiple vdevs of RAID6.<br>
</p>
<p>For RAID in Linux I have been using mdraid. I know LVM does some
Raid but I personally never done myself so can't advise.</p>
<p>Regards.<br>
Fernando<br>
</p>
<br>
<div class="moz-cite-prefix">On 13/11/2017 10:19, Rudi Ahlers wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAAj3DjmTaxR5JEESLTVtqyzk4H_cN6StKVB_JNXBjJtWrDJXEw@mail.gmail.com">
<div dir="ltr">Hi Fernando,
<div><br>
</div>
<div>Thanx. </div>
<div><br>
</div>
<div>I meant to say, the 4th server will be in another office.
It's about 3Km away and I was thinking of using Gluster's
GEOreplication for this purpose. </div>
<div><br>
</div>
<div>I am not a fond user of RAID5 at all. But this raises the
question: does RAID add any unnecessary overhead? I would
rather run RAID 6 or RAI10. </div>
<div>And then, if RAID is the preferred way (over LVM?), as I
don't have dedicated hardware RAID cards, would mdraid add any
benefit?</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Mon, Nov 13, 2017 at 1:47 PM,
FERNANDO FREDIANI <span dir="ltr"><<a
href="mailto:fernando.frediani@upx.com" target="_blank"
moz-do-not-send="true">fernando.frediani@upx.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<p>Helli Rudi</p>
<p>Nice specs.</p>
<p>I wouldn't use GlusterFS for this setup with the third
server in a different location. Just have this server as
an Standalone and replicate the VMs there. You won't
have real time replication, but much less hassle and
probably to have constant failures, specially knowing
you have a wireless link.</p>
<p>For the SSDs I have been using bcache with success.
Relatively simple to setup and pretty good performance.</p>
<p>For your specs as you have 4 mechanical disks I would
recommend you to have a RAID 5 between them (4 disks is
my limit for RAID 5) and a RAID 0 made of SSDs for the
bcache device. If the RAID 0 fails for any reason it
will fall back directly to the mechanical disks and you
can do maintenance on the Node doing live migration in
order to replace the failed disks.</p>
<p>However as you have you have 2 remaining server to
create your cluster you may need to consider GlusterFS
on the top of this RAID to have the replication and
Highavaibility.</p>
<p>Hope it helps.</p>
<p>Fernando<br>
</p>
<div>
<div class="h5"> <br>
<div class="m_-8722418027031101913moz-cite-prefix">On
13/11/2017 08:03, Rudi Ahlers wrote:<br>
</div>
</div>
</div>
<blockquote type="cite">
<div>
<div class="h5">
<div dir="ltr">Hi,
<div><br>
</div>
<div>Can someone please give me some pointers,
what would be the best setup for performance and
reliability?</div>
<div><br>
</div>
<div>We have the following hardware setup:</div>
<div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px"><br>
</span></font></div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px">3x Supermicro
server with following features per server:</span></font></div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px">128GB RAM</span></font></div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px">4x 8TB SATA
HDD</span></font></div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px">2x SSD drives
(intel_ssdsc2ba400g4 - 400GB DC S3710)</span></font></div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px">2x 12 core CPU
(Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz</span></font></div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px">Quad port
10Gbe Inter NIC</span></font></div>
<div><font color="#2c2c2c" face="Open Sans,
Helvetica, Arial, sans-serif"><span
style="font-size:14.6667px">2x 10GB Cisco
switches (to isolate storage network from
LAN)</span></font></div>
</div>
<div><br>
</div>
<div>
<div>One of the servers will be in another
office, with a 600Mb wireless link for
Disaster Recovery. </div>
<div><br>
</div>
<div>What is recommended for the best setup in
terms of redundancy and speed?</div>
<div><br>
</div>
<div>I am guessing GlusterFS with a Distributed
Striped Replicated Volume across 3 of the
servers. </div>
<div><br>
</div>
<div>For added performance I want to use the SSD
drives, perhaps with dm-cache?</div>
<div><br>
</div>
<div>Should I combine the 4x HDD's using LVM on
each host node?</div>
<div>What about RAID 6?</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div>
<div>Virtual Machines will then reside on the
oVirt Cluster and any one of the 3 host
nodes can fail, or any single HDD can fail
and all should still work, right/? </div>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
-- <br>
<div
class="m_-8722418027031101913gmail_signature">Kind
Regards<br>
Rudi Ahlers<br>
Website: <a
href="http://www.rudiahlers.co.za"
target="_blank" moz-do-not-send="true">http://www.rudiahlers.co.za</a><br>
</div>
</div>
</div>
<br>
<fieldset
class="m_-8722418027031101913mimeAttachmentHeader"></fieldset>
<br>
</div>
</div>
<pre>______________________________<wbr>_________________
Users mailing list
<a class="m_-8722418027031101913moz-txt-link-abbreviated" href="mailto:Users@ovirt.org" target="_blank" moz-do-not-send="true">Users@ovirt.org</a>
<a class="m_-8722418027031101913moz-txt-link-freetext" href="http://lists.ovirt.org/mailman/listinfo/users" target="_blank" moz-do-not-send="true">http://lists.ovirt.org/<wbr>mailman/listinfo/users</a>
</pre>
</blockquote>
<br>
</div>
<br>
______________________________<wbr>_________________<br>
Users mailing list<br>
<a href="mailto:Users@ovirt.org" moz-do-not-send="true">Users@ovirt.org</a><br>
<a href="http://lists.ovirt.org/mailman/listinfo/users"
rel="noreferrer" target="_blank" moz-do-not-send="true">http://lists.ovirt.org/<wbr>mailman/listinfo/users</a><br>
<br>
</blockquote>
</div>
<br>
<br clear="all">
<div><br>
</div>
-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">Kind
Regards<br>
Rudi Ahlers<br>
Website: <a href="http://www.rudiahlers.co.za"
target="_blank" moz-do-not-send="true">http://www.rudiahlers.co.za</a><br>
</div>
</div>
</blockquote>
<br>
</body>
</html>