On Thu, Apr 18, 2013 at 08:25:50AM -0500, Mark Nelson wrote: > thanks for your answer! > It makes me a bit nervous that you are seeing such a discrepancy > between the drives. Were you expecting that one server would be so > much faster than the other? If a drive is is starting to fail your > results may be unpredictable. > the two servers are far from identical unfortunatly. first server has two sas 15krpm drives in a RAID 1 (PERC 5/i) second has two sata 7.2krpm dives in a RAID 1 (aacraid CERC) > > Are you doing replication? yes, as I use default replication which is 2 by default. > If one server has a slower drive, doing > 2x replication, and you are using XFS (which tends to have some > performance overhead with ceph) that might get you down into this > range given than 50MB/s number you posted above. I don't understand why I can only send datas at 15MB/s when it should be written to two devices that can do 50MB/s :( Can you explain me a bit more on this or point me to some design doc? Xfs is the recommended FS for the kernel used (3.2.0). And btrfs is still experimental :-/ > You may try > connecting to the OSD admin sockets during tests and poll to see if > all of the outstanding operations are backing up on one OSD. > > Sebastien has a nice little tutorial on how to use the admin socket here: > > http://www.sebastien-han.fr/blog/2012/08/14/ceph-admin-socket/ > thanks, I'm going to look at this ... _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |