check_mem errors

[Thomas Guyot-Sionnest]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 29/05/08 07:14 AM, Dirk H. Schulz wrote:
> Hello nagios fellows,
> 
> I am running a nagios test environment on CentOS 4 and RHEL4/5, and came to 
> recognize some errors in check_mem.pl:
> 
> - if used with option -f (checks free memory), it does not report back free 
> memory - the amount reported corresponds to cached memory.
> - if used with option -u (checks used memory), it reports wrong 
> percentages, e.g. if 2.6 GB of 4 GB on a 32Bit System is used it reports 93 
> % used.
> 
> Are these known errors? I did not find much relating to that.
> Is there a replacement for check_mem.pl?

I never used check_mem, be be aware that Linux can cache all free memory
while still having is available for any process than need it. On some
servers with very stable loads the "free" memory can get down to only a
few megs (out of many GBs) but if you take into account cached memory
that can be freed up any time the picture is much different.

I wrote this memory check (using Nagios::Plugin) that can take absolute
values and percentages as thresholds. It parses free(1) and returns the
amount of memory available, counting cached memory into account. It also
let you choose the unit to display free memory with:

http://www.nagiosexchange.org/cgi-bin/page.cgi?g=1433.html;d=1

Since your system will always keep some memory in buffers/cache you
should take this into account when setting thresholds.

Thomas

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFIPqU/6dZ+Kt5BchYRAmDbAKCYXpcxpxqP15Oc6n+QKYlu6dDVrgCgprZJ
6urqcEJuIGUdlNAuL9t+KtM=
=EYq6
-----END PGP SIGNATURE-----

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
Nagios-users mailing list
Nagios-users at lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nagios-users
::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. 
::: Messages without supporting info will risk being sent to /dev/null