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<font size="-1">Hello everybody,<br>
here i come here again, this time to ask some hint about how to
monitor GPFS.<br>
<br>
I know about mmpmon, but the issue with its "fs_io_s" and "io_s"
is that they return number based only on the request done in the
current host, so i have to run them on all the clients ( over 600
nodes) so its quite unpractical. Instead i would like to know
from the servers whats going on, and i came across the vio_s
statistics wich are less documented and i dont know exacly what
they mean. There is also this script
"/usr/lpp/mmfs/samples/vdisk/viostat" that runs VIO_S.<br>
<br>
My problems with the output of this command:<br>
</font>
<blockquote>
<blockquote><font size="-1"><tt> echo "vio_s" |
/usr/lpp/mmfs/bin/mmpmon -r 1</tt></font><br>
<br>
<font size="-1"><tt>mmpmon> mmpmon node 10.7.28.2 name gss01a
vio_s OK VIOPS per second</tt></font><br>
<font size="-1"><tt>timestamp:
1409763206/477366</tt></font><br>
<font size="-1"><tt>recovery group: *</tt></font><br>
<font size="-1"><tt>declustered array: *</tt></font><br>
<font size="-1"><tt>vdisk: *</tt></font><br>
<font size="-1"><tt>client reads:
2584229</tt></font><br>
<font size="-1"><tt>client short writes:
55299693</tt></font><br>
<font size="-1"><tt>client medium writes:
190071</tt></font><br>
<font size="-1"><tt>client promoted full track writes:
465145</tt></font><br>
<font size="-1"><tt>client full track writes:
9249</tt></font><br>
<font size="-1"><tt>flushed update writes:
4187708</tt></font><br>
<font size="-1"><tt>flushed promoted full track writes:
123</tt></font><br>
<font size="-1"><tt>migrate operations:
114</tt></font><br>
<font size="-1"><tt>scrub operations:
450590</tt></font><br>
<font size="-1"><tt>log writes:
28509602</tt></font><br>
</blockquote>
</blockquote>
<font size="-1"><br>
</font><font size="-1">it sais "</font><font size="-1">VIOPS per
second", but they seem to me just counters as every time i re-run
the command, the numbers increase by a bit.. <br>
Can anyone confirm if those numbers are counter or if they are
OPS/sec.<br>
<br>
On a closer eye about i dont understand what most of thosevalues
mean. For example, what exacly are </font><font size="-1">"</font><font
size="-1">flushed promoted full track write" ?? <br>
I tried to find a documentation about this output , but could not
find any. can anyone point me a link where output of vio_s is
explained?<br>
<br>
Another thing i dont understand about those numbers is if they are
just operations, or the number of blocks that was read/write/etc .
I'm asking that because if they are just ops, i don't know how
much they could be usefull. For example one write operation could
eman write 1 block or write a file of 100GB. If those are
oprations, there is a way to have the oupunt in bytes or blocks?<br>
<br>
Last but not least.. and this is what i really would like to
accomplish, i would to be able to monitor the latency of metadata
operations. <br>
In my environment there are users that litterally overhelm our
storages with metadata request, so even if there is no massive
throughput or huge waiters, any "ls" could take ages. I would like
to be able to monitor metadata behaviour. There is a way to to do
that from the NSD servers?<br>
<br>
Thanks in advance for any tip/help.<br>
<br>
Regards,<br>
Salvatore<br>
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