On Aug 01, 2008 14:29 -0400, John Parhizgari wrote: > After doing a few experimental read tests while examining > /proc/fs/lustre/osc/OSTID/stats on the lustre client: > > It seems to be that the 7th column of the stats file, on the ost_read > line, represents the total bytes read for all the RPC calls involving > reading from that OST up until now (2773483520 in the example below). > ost_read 91655 samples [usec] 4096 1048576 2773483520 > 1759238200229888 > > Is this an accurate description of ost_read?
Yes, though unfortunately this statistic was "hijacked" from being the per-RPC latency (hence [usec] units). I've attached a patch to bug 16573 that fixes this, though it is still just a prototype. > If so, does it make sense to use information to track and analyze the > true read stats against OSTs and filesystems (since the llite stats > includes client-cached data reads)? And then also similarly for > ost_write, since we want essentially Lustre's network activity to the > filesystem; if the above holds this will be representative of how much > data is really being transferred to/from the lustre filesystems for each > client. The above patch also tracks these stats on the OST. See also "brw_stats" and "rpc_stats" on the obdfilter devices. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
