<div style="white-space:pre-wrap">XFS on Irix had a feature similar to QoS, called GRIO (guaranteed rate I/O), where applications could reserve a given bandwidth.<br><br><a href="http://www.sgistuff.net/software/irixintro/documents/xfs-whitepaper.html">http://www.sgistuff.net/software/irixintro/documents/xfs-whitepaper.html</a><br><br>Sounds somewhat similar to QoS, but focused on giving applications guaranteed bandwidth, not iops.<br><br><br><br> -jf<br> <br></div><br><div class="gmail_quote"><div dir="ltr">ons. 15. jun. 2016 kl. 00.08 skrev Marc A Kaplan <<a href="mailto:makaplan@us.ibm.com">makaplan@us.ibm.com</a>>:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><font size="2" face="sans-serif">Yes, in QOS for 4.2.0 there are some simple
assumptions that may not make a lot of sense in some configurations, especially
configurations with many (100s) of nodes mounting the same file system...
You can try out what you suggested and in 4.2.0 I think it
will pretty much work as you suggest -- essentially you are allocating
466 maintenance iops to every node, knowing that most of those nodes will
not be using their allocation of IOPS.</font><br><br><font size="2" face="sans-serif">In later releases, you may find that
we will address some of these kinds of quirks in QOS.</font><br><br><font size="2" face="sans-serif">QOS is a new feature for GPFS, and I
don't think you'll find anything like it in any commercial file system
offering. (Correct me with example(s) if I am wrong on this point.)</font><br><font size="2" face="sans-serif">So think of it as "release 1.0"
(of QOS) and let us know how well it works for you and how it might be
improved....<br></font><br><font size="2" face="sans-serif">--marc of Spectrum(GP)FS</font><br><br><br><br><font size="1" color="#5f5f5f" face="sans-serif">From:
</font><font size="1" face="sans-serif">"Buterbaugh, Kevin
L" <Kevin.Buterbaugh@Vanderbilt.Edu></font><br><font size="1" color="#5f5f5f" face="sans-serif">To:
</font><font size="1" face="sans-serif">gpfsug main discussion
list <<a href="mailto:gpfsug-discuss@spectrumscale.org" target="_blank">gpfsug-discuss@spectrumscale.org</a>></font><br><font size="1" color="#5f5f5f" face="sans-serif">Date:
</font><font size="1" face="sans-serif">06/14/2016 04:50 PM</font><br><font size="1" color="#5f5f5f" face="sans-serif">Subject:
</font><font size="1" face="sans-serif">[gpfsug-discuss]
QoS question</font><br><font size="1" color="#5f5f5f" face="sans-serif">Sent by:
</font><font size="1" face="sans-serif"><a href="mailto:gpfsug-discuss-bounces@spectrumscale.org" target="_blank">gpfsug-discuss-bounces@spectrumscale.org</a></font><br><hr noshade><br><br><br><font size="3">Hi All, </font><br><br><font size="3">We have recently upgraded to GPFS 4.2.0-3 and so I am
getting ready to dive into my first attempts at using the new QoS features.
I want to make sure I am understanding the documentation:</font><br><p><font size="2">"The IOPS values that you set in an mmchqos command
apply to all I/O operations that are issued by all the nodes that have
the specified file system mounted. You should adjust your allocations of
IOPS accordingly. </font></p><p><p><font size="2">For example, if you 600 IOPS to the maintenance class,
and there are six nodes that have the file system mounted, then QoS allocates
100 IOPS to the maintenance class of each node. If you then run maintenance
commands that affect only three of the nodes, the commands runs with an
actual allocation of 300 IOPS, or 100 IOPS per node. To run maintenance
commands that affect three nodes with an actual allotment of 600 IOPS,
or 200 per node, allocate 1200 IOPS to the maintenanceclass. "</font></p></p><p><p><p><font size="3">We have a ~700 node cluster with 15 NSD servers. Here’s
how I interpret the above assuming that I have determined that I want to
allow 7,000 IOPs … please correct me if I’m wrong...</font><br><br><font size="3">7,000 IOPs / 700 nodes would be 10 IOPs per node.</font><br><br><font size="3">But I want those 7,000 IOPs to be divided amongst my 15
NSD servers that are going to be doing the maintenance (a restripe, for
example), so 7,000 / 15 = 466.67.</font><br><br><font size="3">466.67 * 700 (nodes in cluster) = 326,666.67. So
I would allocate 326,666 IOPs to the maintenance class?</font><br><br><font size="3">Thanks in advance…</font><br><br><font size="3">Kevin</font><br><font size="3">—</font><br><font size="3">Kevin Buterbaugh - Senior System Administrator</font><br><font size="3">Vanderbilt University - Advanced Computing Center for
Research and Education</font><br></p></p></p><p><p><p><a href="mailto:Kevin.Buterbaugh@vanderbilt.edu" target="_blank"><font size="3" color="blue"><u>Kevin.Buterbaugh@vanderbilt.edu</u></font></a><font size="3">- (615)875-9633</font></p></p></p><p><p><p><br><br><br><tt><font size="2">_______________________________________________<br>gpfsug-discuss mailing list<br>gpfsug-discuss at <a href="http://spectrumscale.org" target="_blank">spectrumscale.org</a><br></font></tt><a href="http://gpfsug.org/mailman/listinfo/gpfsug-discuss" target="_blank"><tt><font size="2">http://gpfsug.org/mailman/listinfo/gpfsug-discuss</font></tt></a><tt><font size="2"><br></font></tt><br><br>
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