<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Oct 10, 2017 at 3:31 PM, Dmitri Chebotarov <span dir="ltr"><<a href="mailto:dchebota@gmu.edu" target="_blank">dchebota@gmu.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Good Morning<br>
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I'm using virtio-scsi (also tried virtio), not using IDE (doesn't IDE have 4 devices limit? it's long time since I used IDE...).<br>
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This is for servers hosting own/nextCloud and Samba for a small/medium groups with large datasets (60-80TB) per server.<br>
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If ovirt-scsi allows to attach >20 disks then it meets my needs in this case. Thank you.<br>
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The reason I opted for LVM is performance. It's so much faster with LVM and striped volumes compared to a single large disk. I'm seeing very high 'iowait' numbers (to the point when VM is unresponsive) when I'm dumping large amount of data to a single disk. But with LVM striped volumes 'iowait' at around ~20% and I can get to ~750MB/s in the same environment (same config with single disk is ~160MB/s).<br></blockquote><div><br></div><div>Interesting. What version of Gluster are you using? Are you using sharding? What's the underlying storage for Gluster and how is it set up?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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Also, healing a single large disk on gluster takes ages (I'm using erasure coded volumes) .<br></blockquote><div><br></div><div>Sharding and newer versions of Gluster should help here.</div><div>Y.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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Thank you,<br>
--<br>
Dmitri Chebotarov.<br>
George Mason University,<br>
4400 University Drive,<br>
Fairfax, VA, 22030<br>
GPG Public key# 5E19F14D: [<a href="https://goo.gl/SlE8tj" rel="noreferrer" target="_blank">https://goo.gl/SlE8tj</a>]<br>
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______________________________<wbr>__________<br>
</span>From: Yaniv Kaul <<a href="mailto:ykaul@redhat.com">ykaul@redhat.com</a>><br>
Sent: Tuesday, October 10, 2017 4:03:08 AM<br>
<span class="">To: Dmitri Chebotarov<br>
Cc: <a href="mailto:users@ovirt.org">users@ovirt.org</a><br>
Subject: Re: [ovirt-users] Maximum storage per VM?<br>
<br>
</span><span class="">On Fri, Oct 6, 2017 at 10:24 PM, Dmitri Chebotarov <<a href="mailto:dchebota@gmu.edu">dchebota@gmu.edu</a><mailto:<a href="mailto:dchebota@gmu.edu">dcheb<wbr>ota@gmu.edu</a>>> wrote:<br>
Hello<br>
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I'm trying to find any info on how much storage I can attach to a VM.<br>
<br>
Is there a recommended/maximum for number of disks and maximum disk size?<br>
<br>
Disk count depends on the interface - IDE - very few, virtio- 20-something (depends on the number of PCI slots available), virtio-SCSI - more.<br>
What is the use case?<br>
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I'm using GlusterFS as backend storage for the cluster.<br>
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The VM uses LVM (/w striped volumes) to manage attached disks.<br>
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Aren't you having layers over layers over layers? Is that the optimal arrangement?<br>
(Again, would be interesting to understand the use case to better provide information).<br>
Y.<br>
<br>
<br>
Thank you,<br>
--<br>
Dmitri Chebotarov.<br>
George Mason University,<br>
4400 University Drive,<br>
Fairfax, VA, 22030<br>
GPG Public key# 5E19F14D: [<a href="https://goo.gl/SlE8tj" rel="noreferrer" target="_blank">https://goo.gl/SlE8tj</a>]<br>
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