[Lustre-discuss] client I/O

[Andreas Dilger]

On 2009-12-04, at 20:18, Mag Gam wrote:
> Is it possible to figure out what client is taking up the most I/O? We
> have 8 OSS and 200 clients and it seems 5 to 6 clients are taking up
> all the bandwidth and I am trying to figure out who it is...


In newer versions of Lustre (1.8 definitely, and later 1.6.x) there is  
an "exports" directory that contains statistics about each client,  
including brw_stats.

Alternately, you can just enable the RPC statistics and then dump the  
debug logs after a some seconds and check for the OST_READ(3) and  
OST_WRITE(4).

lctl set_param debug=+rpctrace
sleep 20
lctl dk /tmp/debug
grep "Handled.*:[34]$" /tmp/debug

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.