Is it possible to monitor the disk usage of a volume group? What should I put in rrdsettings.cfg for a volume group (named VG) that spans sda, sdb and sdc?

Thanks in advance.

vtdstein95

My first guess would be "/dev/mapper/vg-myth".

Thanks tjc.

Looks like 'vg-myth' is the answer. I now have two effective usage sections for 4 HDDs.

My rrsettings.cfg:


cron.hourly does not appear to work, so i updated my crontab to include rrd_usage.pl as follows:


'pretty' in cron.hourly does work, so could it be that in the rrd_km file (created per the wiki) #!/bin/bash or something similar is missing?

vtdstein95

On the cron question it is more likely I needed to restart cron, anyway giving it a try.

i didn't see a disk usage graph after following the wiki.

I tried to run it manually and realized i needed to



now two graphs are there for each drive.

not sure if this should be added to the wiki or not.

Yes. If the directions assume that everyone knows enough to do that they're broken.

Has anyone gotten the rrd_usage.pl script to work with a volume group? I tried following the example above and using the last part of my device in the rrdsettings.cfg file, but the script seems to ignore the device and doesn't create an rrd file.

Here is my df output:



and here is the rrdsettings.cfg file:


Any thoughts?

If you notice, when you type in DISKDEV=hda1:/ it is referring to /dev/hda1 whereas myth-storage I think would be referring to /dev/myth-storage. Try DISKDEV=mapper/myth-storage:/myth. I'm not sure if that's it but it would kind of make sense.

A fine idea, which I hadn't tried. Still doesn't create the rrd file.

I've updated my rdd_usage.pl script to work with volume group's
(now that I have set one up)

I'd like to know if it works ok for others. you can grab it with the following



I'd be interested in some feedback ok it, I'll update the wiki once I'm sure it all works.

(I'm in the process of moving and only have the one system setup, so I've only done some basic tests )