Re: Sudden drop in DBb performance

On 6 Září 2011, 10:26, Gerhard Wohlgenannt wrote:
> Thanks a lot to everybody for their helpful hints!!!
>
> I am running all these benchmarks while the VMs are up .. with the
> system under something like "typical" loads ..
>
> The RAID is hardware based. On of my colleagues will check if there is
> any hardware problem on the RAID (the disks) today, but nothing no
> errors have been reported.
>
> please find below the results of
> iostat -x 2
> vmstat 2
>
> hmm, looks like we definitely do have a problem with I/O load?!
> btw: dm-19 is the logical volume where the /var (postgresql) is on ..

Well, it definitely looks like that. Something is doing a lot of writes on
that drive - the drive is 100% utilized, i.e. it's a bottleneck. You need
to find out what is writing the data - try iotop or something like that.

And it's probably the reason why the bonnie results were so poor.

Tomas