[Xymon] iostat for Linux

[Colin Coe]

On Wed, Aug 8, 2012 at 4:43 AM, John Horne <john.horne at plymouth.ac.uk> wrote:
> On Tue, 2012-08-07 at 09:52 +0800, Colin Coe wrote:
>> Hi all
>>
>> Google knows a lot about $SUBJECT but unfortunately, a lot of the info
>> is conflicting.
>>
>> What's the current wisdom for collecting and graphing iostat info on
>> Linux?  Specifically, I'm using RHEL5 and RHEL6.
>>
> Hi,
>
> I recently asked about monitoring iostat myself - see the thread here
> http://lists.xymon.com/pipermail/xymon/2012-August/035229.html
>
> One reply mentions some scripts on xymonton. I also received a private
> reply that there were some scripts on Sourceforge - search for 'Linux
> iostat'.
>
> I ended up writing a reasonably short script myself which runs on the
> clients. It records the 'avtime', 'svctime' and the percent 'busy'
> values. I produce two graphs - one for the percent busy, the other shows
> both time values. Both graphs appear in 'trends', and the 'busy' graph
> appears on an 'iostats' test status page. (Note, because Xymon already
> sort of knows about an 'iostat' test I could not use that name, so used
> 'iostats' instead.) The script sends a 'status' report (using 'xymon
> <server> "status ...") for the 'iostats' test. If the percent busy is
> high it sends a yellow status, if it is very high then a red status is
> sent. Additionally, a 'data' report (using 'xymon <server> "data ...")
> containing the time and busy values is sent back to the Xymon server. On
> the server I run a script which is used by 'xymon_rrd' (via the
> '--extra-script' and '--extra-tests' options; see the man page and look
> in tasks.cfg). The script tells Xymon what RRD files to create and what
> the DS entries and values are, from the data received from the client.
> (Sorry, that may all sound horrendously complicated. However, it works
> very well, and once set up is very easy to maintain. I currently run
> three tests like this.)
>
> I would say that monitoring iostat has proved to be useful to us. It is
> not something we monitored with Big Brother, but has already shown that
> we have two servers which regularly show very high disk I/O. No idea why
> yet.
>
>
>
>
>
> John.
>
> --
> John Horne, Plymouth University, UK
> Tel: +44 (0)1752 587287    Fax: +44 (0)1752 587001
>

Thanks John & Alan

I've now looked at a few iostat monitors for xymon including
http://sourceforge.net/projects/xy-alfanoid/files/ and
http://sourceforge.net/projects/xy-alfanoid/files/.

One of the common things I really don't like is the modification of
the TEST2RRD variable within xymonserver.cfg.  My guess is this is
unavoidable but it means manually handling after xymon upgrades and I
have more than enough to do now than worry about manual steps after
software upgrades.

Henrik, is there a good way that the above can be handled?
xymonserver.cfg looks like a shell script, does it act like one?  e.g.
can we do something like 'TEST2RRD=$TEST2RRD:customtest=a,b,c' in an
include file. Same for GRAPHS.  Apologies if this is spelt out
somewhere and I've missed it.  BTW, I really like the "*.d"
directories that have come in in very recent xymon versions.
Referring to http://lists.xymon.com/pipermail/xymon/2012-August/035231.html,
what would it take to get the iostat tests up to scratch?  (I'm
selfishly referring exclusively to Linux, specifically RHEL5 and
above.)

While I'm on a bit of a whine, in the RHEL/Fedora realm, nagios for
example has heaps of plugin RPMs.  I would be great if the best of
breed custom tests were assembled and packaged in a similar manner.

Lastly, this email is not intended to offend, just to try and get the
best solution for monitoring disk stats possible.

Thanks

CC

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RHCE#805007969328369