I have the journals on a separate disk too. How do you disable the snapshotting on the OSD?
Thanks, Erik. On 22-06-15 12:27, Krzysztof Nowicki wrote: > AFAIK the snapshots are useful when the journal sits inside the OSD > filesystem. In case the journal is on a separate filesystem/device then > OSD BTRFS snapshots can be safely disabled. I have done so on my OSDs as > they all use external journals and experienced a reduction in periodic > writes, but they are not completely gone. > > pon., 22.06.2015 o 11:27 użytkownik Jan Schermer <j...@schermer.cz > <mailto:j...@schermer.cz>> napisał: > > I don’t run Ceph on btrfs, but isn’t this related to the btrfs > snapshotting feature ceph uses to ensure a consistent journal? > > Jan > >> On 19 Jun 2015, at 14:26, Lionel Bouton <lionel+c...@bouton.name >> <mailto:lionel+c...@bouton.name>> wrote: >> >> On 06/19/15 13:42, Burkhard Linke wrote: >>> >>> Forget the reply to the list... >>> >>> -------- Forwarded Message -------- >>> Subject: Re: [ceph-users] Unexpected disk write activity with >>> btrfs OSDs >>> Date: Fri, 19 Jun 2015 09:06:33 +0200 >>> From: Burkhard Linke >>> <burkhard.li...@computational.bio.uni-giessen.de> >>> <mailto:burkhard.li...@computational.bio.uni-giessen.de> >>> To: Lionel Bouton <lionel+c...@bouton.name> >>> <mailto:lionel+c...@bouton.name> >>> >>> >>> >>> Hi, >>> >>> On 06/18/2015 11:28 PM, Lionel Bouton wrote: >>> > Hi, >>> *snipsnap* >>> >>> > - Disks with btrfs OSD have a spike of activity every 30s (2 intervals >>> > of 10s with nearly 0 activity, one interval with a total amount of >>> > writes of ~120MB). The averages are : 4MB/s, 100 IO/s. >>> >>> Just a guess: >>> >>> btrfs has a commit interval which defaults to 30 seconds. >>> >>> You can verify this by changing the interval with the commit=XYZ mount >>> option. >> >> I know and I tested commit intervals of 60 and 120 seconds without >> any change. As this is directly linked to filestore max sync >> interval I didn't report this test result. >> >> Best regards, >> >> Lionel >> _______________________________________________ >> ceph-users mailing list >> ceph-users@lists.ceph.com <mailto:ceph-users@lists.ceph.com> >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com <mailto:ceph-users@lists.ceph.com> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
