[Lustre-discuss] help tracking down extremely high loads on OSSs

[Johann Lombardi]

On Tue, Oct 19, 2010 at 11:21:25AM -0400, Jason Hill wrote:
> Also something to look at if you aren't having any luck with other avenues
> would be the debug log with RPC trace enabled. We do something like:
>
> echo +rpctrace > /proc/sys/lnet/debug; 
> lctl dk > /dev/null; sleep 60; 
> lctl dk > /tmp/rpctrace; echo -rpctrace > /proc/sys/lnet/debug

FYI, a request history for each service is also available through /proc.
# lctl get_param ost.OSS.*.req_history

For more details, see:
http://wiki.lustre.org/manual/LustreManual18_HTML/LustreDebugging.html#50593922_47732

HTH
Johann