On Tuesday 02 October 2007 07:10, Andreas Dilger wrote: > > Could this problem come from multipath? It is "assembling" the dm-* devices > > out of the SCSI devices, presents the SCSI devices as "slaves", but has no > > own settings for the queue parameters in /sys/block/dm-*. I tried increasing > > the SCSI member devices' queue max_sectors_kb before starting the > > multipathd, > > but it didn't help. Uhmmm, yes, I am using multipath... forgot to mention > > earlier. > > It seems entirely possible, I haven't looked at the multipath code myself. > It should really build the q->max_* values as the minimum of all of the > underlying devices instead of using a default value.
Without multipath (mounting the scsi devices directly) the change of max_sectors_kb has the expected effect: Lustre stops to fragment and I/Os are done in 1MB chunks. I recon I was unable to find the place where max_sectors for the multipath queues is set, will continue to look into this. Regards, Erich _______________________________________________ Lustre-discuss mailing list [email protected] https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
