[hobbit] disk groups

[Henrik Stoerner]

On Sun, Aug 28, 2005 at 03:06:40PM -0400, Galen Johnson wrote:
> I have a question.  Is it possible to set up disk groups that hobbit can
> then treat as a single disk?  I did something similar to this using an
> inhouse script we use for a home grown alerting system.  We have an
> application that spreads itself across several partitions and I only
> care if the average across the partitions is at some threshhold not the
> individual partitions.
> 
> Is this currently possible with hobbit (I know it's not in BB)?

No, I haven't come across this setup before now.

> would it be possible to add this functionality to it? (it was pretty
> straightforward for the stuff I did but that was perl based and I just
> used the XML module in perl.)

Anything is possible ... there are several ways of doing this.

One possibility is that you write a client-side script to look at the
disk utilisation. If you modify the hobbit client running on this box
so it doesn't send back and "df" output, then it won't generate a "disk"
status, so your client-side script could just send in a "disk" status
report.

Another way of doing it is to write a custom Hobbit module to process
the "df" data on the Hobbit server, as they are reported by the client.
Hobbit allows you to add extra modules that are fed the data sent into
Hobbit by e.g. clients - so you could run (via hobbitlaunch)

   hobbitd_channel --channel=client /usr/local/bin/mydiskmon.sh

and your script would be fed all of the data sent by the clients; it
would then need to filter out the interesting data for itself.


Regards,
Henrik