<div dir="ltr">Hello Rafi,<div><br></div><div>Thanks for the reply please see my answers below</div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Sep 3, 2016 at 12:07 AM, Mohammed Rafi K C <span dir="ltr"><<a href="mailto:rkavunga@redhat.com" target="_blank">rkavunga@redhat.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>Hi Benjamin,</p>
<p><br>
</p>
<p>Can you tell us more about your work-load like the file size</p></div></blockquote><div>Files are a range from 10GB test file generated from /dev/urandom, many 100MB folder separated files to smaller images and text files</div><div>This is a lab so typically there is no load, in the case of my testing this issue the only file being accessed was the 10GB test file. </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000"><p>,
size of both hot and cold storage</p></div></blockquote><div>Hot storage is a 315GB portion of a 512GB SSD</div><div>Cold storage is a replica made up of 3 bricks on two nodes. totaling 17TB</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000"><p>how the files are created
(after attaching the tier or before attaching the tier)</p></div></blockquote><div>I've experienced performance issues with files created before hot attachment, 10GB test file, and copying files to the volume after attachment (100MB files) </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000"><p>, how long
have you been using the tier volume, etc.</p></div></blockquote><div>At the moment I am not using the hot tier after discovering the performance loss. I originally turned on after learning of the feature a month or so ago. I feel like I may have actually had this issue since then because I have been troubleshooting a network throughalput issue since then that was contributing to a 4MB/s write to the volume. I recently resolved that issue and the 4MB/s write was still observed until I removed the hot tier.</div><div><br></div><div>Unfortunate timing on both issues.</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000">
<p><br>
</p>
<p>Regards</p>
<p>Rafi KC<br>
</p><div><div class="h5">
<p><br>
</p>
<p><br>
</p>
<br>
<div>On 09/03/2016 09:16 AM, Benjamin
Kingston wrote:<br>
</div>
</div></div><blockquote type="cite"><div><div class="h5">
<div dir="ltr">
<div class="gmail_quote">
<div dir="ltr">Hello all,
<div><br>
</div>
<div>I've discovered an issue in my lab that went unnoticed
until recently, or just came about with the latest Centos
release.</div>
<div><br>
</div>
<div>When the SSD hot tier is enabled read from the volume
is 2MB/s, after detaching AND committing, read of the same
file is at 150MB/s to /dev/null</div>
<div><br>
</div>
<div>If I copy the file to the hot bricks directly the write
is 150MB/s and read is 500MB/s on the first read, and then
4GB/s on the subsequent reads (filesystem RAM caching) to
/dev/null</div>
<div><br>
</div>
<div>Just enabling tier storage takes the performance to
~10-20IOPS and 2-10MB/s even for local node mounted
volume.</div>
<div><br>
</div>
<div>I don't see any major log issues and I detached and did
a fix-layout, but it persists when re-enabling the tier.</div>
<div><br>
</div>
</div>
</div>
<br>
</div>
<br>
<fieldset></fieldset>
<br>
</div></div><pre>______________________________<wbr>_________________
Gluster-users mailing list
<a href="mailto:Gluster-users@gluster.org" target="_blank">Gluster-users@gluster.org</a>
<a href="http://www.gluster.org/mailman/listinfo/gluster-users" target="_blank">http://www.gluster.org/<wbr>mailman/listinfo/gluster-users</a></pre>
</blockquote>
<br>
</div>
</blockquote></div><br></div></div>