[Xymon] Checking disk space on a "backup" system

[Adam Goryachev]

On 11/04/13 00:27, Michael Beatty wrote:
> All of the hosts that I will be monitoring have a backup.  This backup
> is, for most all practical purposes, idle.  It does nothing but sits
> and wait for someone to move it into production.  The primary system
> copies files and database exports over to this backup system.  I had
> no intention on running a Xymon client on these backup systems (though
> one would be installed and waiting to be started), the only monitoring
> is a ping test.
>
> With that said, one exposure that exists on these backup systems is
> that the disk space in the file system has the potential to fill up. 
> Is there any functionality built into xymon that would let me check
> the disk space on this remote system and report it back from the
> primary system?
>
> My initial thought was to write an extension script that does an 'rsh
> backup du /home/user/' and parsing the results and test against a
> threshold, but I would prefer to utilize what is built into xymon
> before recreating the wheel.

Just mount the backup FS onto the live machine? Use sshfs, NFS, or
whatever else is convenient. Make sure xymon is configured to report
this type of remote mounted filesystems (I think the default is to not
check remote mounts).

Personally, I'd prefer to install an actual xymon client, and monitor
the backup machine fully to ensure that it will be fully operational
when you need it. Nothing worse than having a problem on the live
server, and then find the backup machine died last week but is still
pingable, or whatever. Just consider Murphy's Law, it will fail in the
worst possible way, at the worst possible time. (Or whatever he actually
said).

Oh, going back to your original question...
Adjust the xymonclient to call a local script instead of /usr/bin/df or
whatever. Make that script call the local /usr/bin/df, as well as
collect the data from the backup machine. Prepend "backup" to all device
names and mountpoints on the backup server, and then combine the local
and remote data together. This allows you to differentiate the backup
system within xymon (ie, 75% full for production and 90% full for backup
systems, etc).

Hope one of the above helps....

Regards,
Adam

-- 
Adam Goryachev
Website Managers
www.websitemanagers.com.au