We've got problems

[Kostas Georgiou]

On Thu, Dec 18, 2008 at 03:06:34PM -0600, Mike McGrath wrote:

> nfs1:
> 
> NFS1's IO load is just not right.  Something isn't behaving as it should
> and I'm just not sure whats going on there yet.  We need to do a full
> examination and trend of it.  This involves moving cvs1 to another
> location and involves moving releng2 to xen1 to help ease some load.
> Additionally we need to move kojipkgs1 to another location (probably xen1)
> and enable a proper caching for it.  We also need to finally get a valid
> backup of nfs1.  This still hasn't happened.  Its difficult to test
> because of the high load on the disks, backups take 4+ days.  lots of
> things can go wrong during that time.

Something like disktop.stp from http://sourceware.org/systemtap/wiki/ScriptsTools
might be usefull in finding out what is causing the load.

Also have a look at https://bugzilla.redhat.com/show_bug.cgi?id=448130
if you are using the default CFQ IO scheduler and NFS1 is used for nfs
traffic as the name suggests (it isn't just nfs pefrormance that is
affected by slice_idle though).

Kostas