2011/10/15 Martin Mailand <martin@xxxxxxxxxxxx>: > Hi Christian, > I have a very similar experience, I also used josef's tree and btrfs snaps = > 0, the next problem I had than was excessive fragmentation, so I used this > patch http://marc.info/?l=linux-btrfs&m=131495014823121&w=2, and changed the > btrfs option to (btrfs options = noatime,nodatacow,autodefrag) that kept the > fragmentation under control. > But even with this setup after a few days the load on the osd is unbearable. How did you find out about our fragmentation issues? Was it just a performance problem? > As far as I understood the doku if you disable the btrfs snapshot > functionality the writeahead journal is activated. > http://ceph.newdream.net/wiki/Ceph.conf > And I get this in the logs. > mount: enabling WRITEAHEAD journal mode: 'filestore btrfs snap' mode is not > enabled > > May I asked what kind of probs you did have with ext4? Because I am looking > into this direction as well. You can read about our ext4 problems here: http://marc.info/?l=ceph-devel&m=131201869703245&w=2 Our bugreport with RedHat didn't make any progress for a long time, but last week RedHat made two sugestions: - If you configure ceph with 'filestore flusher = false', do you see any different behavior? - If you mount with -o noauto_da_alloc does it change anything? Since I have just migrated to btrfs, I've some problems to check this, but I'll try to do this as soon as I can get hold of some extra hardware. Regards, Christian -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
