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? 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. John Parhizgari wrote: > Simply, I would like to be able to access lustre client data statistics > for each filesystem that excludes statistics for cached reads. > > It is my understanding that for the lustre client (at least on version > 1.6.4.2) the /proc lustre stats for the client for each fs > (/proc/fs/lustre/llite/FSNAME/stats) report the total number of bytes > read (reported in the line read_bytes), and that this number also > includes the total number of bytes read using client-cached data. > > First of all, is my understanding correct for this version of lustre? > And does this apply also for newer versions? > > It has been suggested to subtract the lustre IO from the network IO to > get this data, but this is only applicable if the network is dedicated > to Lustre IO, which is not the case. > > For the moment it seems only the number of cached reads are being > reported in /proc, and not the actual sizes, so this -seems- difficult > or impossible. > > Is there another way (perhaps even in a newer version of lustre) to find > the true read rate for the lustre client that excludes cached reads? > > -- > John Parhizgari > _______________________________________________ > Lustre-discuss mailing list > [email protected] > http://lists.lustre.org/mailman/listinfo/lustre-discuss > > > _______________________________________________ Lustre-discuss mailing list [email protected] http://lists.lustre.org/mailman/listinfo/lustre-discuss
