Le 18/04/2017 à 11:24, Jogi Hofmüller a écrit : > Hi, > > thanks for all you comments so far. > > Am Donnerstag, den 13.04.2017, 16:53 +0200 schrieb Lionel Bouton: >> Hi, >> >> Le 13/04/2017 à 10:51, Peter Maloney a écrit : >>> Ceph snapshots reaaaally slow things down. > I can confirm that now :( > >> We use rbd snapshots on Firefly (and Hammer now) and I didn't see any >> measurable impact on performance... until we tried to remove them. We >> usually have at least one snapshot per VM image, often 3 or 4. > This might have been true for hammer and older versions of ceph. From > what I can tell now, every snapshot taken reduces performance of the > entire cluster :( The version isn't the only difference here. We use BTRFS with a custom defragmentation process for the filestores, which is highly uncommon for Ceph users. As I said, Ceph has support for BTRFS CoW, so a part of the snapshot handling processes is actually handled by BTRFS. Lionel _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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