[DRBD-user] munin "disk utilization" plugin and drbd

[Nick Morrison]

Note: Whilst writing this email, I installed the "sysstat" package and the graphs
look like they should now. They immediately dropped to what they should be. I'll
send this anyway, just in case someone else has the same brainfade :-)

Please refer to:

http://nick.on.net/drbd/utilization.png
http://nick.on.net/drbd/throughput.png

.. some of those DRBD resources show really really high utilization.  A bit weird.
All of my resources are primary/secondary.  Some are primary on kvm-host-01, some on
kvm-host-02.  they're certainly not being written to as much as munin's utilization
graph suggests.

Running "iostat 1" looks like this most of the time:

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.25    0.00    0.50    0.00    0.00   99.26

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda               3.00         0.00         8.00          0          8
dm-0              0.00         0.00         0.00          0          0
dm-1              0.00         0.00         0.00          0          0
dm-2              0.00         0.00         0.00          0          0
drbd0             0.00         0.00         0.00          0          0
dm-3              0.00         0.00         0.00          0          0
drbd1             0.00         0.00         0.00          0          0
dm-4              0.00         0.00         0.00          0          0
drbd4             0.00         0.00         0.00          0          0
dm-5              0.00         0.00         0.00          0          0
drbd2             0.00         0.00         0.00          0          0
dm-6              0.00         0.00         0.00          0          0
drbd5             0.00         0.00         0.00          0          0
dm-7              0.00         0.00         0.00          0          0
drbd3             0.00         0.00         0.00          0          0
dm-8              0.00         0.00         0.00          0          0
dm-9              1.00         0.00         8.00          0          8
dm-10             0.00         0.00         0.00          0          0
drbd8             0.00         0.00         0.00          0          0
dm-11             0.00         0.00         0.00          0          0

... but I suppose the munin plugin is getting its data from elsewhere.

( ... 30 minutes later ... )

solution:  apt-get install sysstat

The problem went away.  I haven't delved deeper to figure out why.


Hope that helps someone.. :-)

Cheers,
Nick