On Mon, 5 Jan 2015, Stefan Priebe wrote: > > Am 05.01.2015 um 19:36 schrieb Stefan Priebe: > > Hi devs, > > > > while btrfs is now declared as stable ;-) i wanted to retest btrfs on > > our production cluster on 2 out of 54 osds. So if they crash it doesn't > > hurt. > > > > While if those OSDs run XFS have spikes of 20MB/s every 4-7s. The same > > OSDs after formatting them with btrfs have spikes of 190MB/s every 4-7s. > > > > Why does just another filesystem raises the disk load by a factor of 10? > > OK this seems to happen cause ceph is creating every 5s a new subvolume / > snap. Is this really expected / needed? You can disable it with filestore btrfs snap = false I'm curious how much this drops the load down; originally the snaps were no more expensive than a regular sync but perhaps this has changed... sage -- 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
