I’d say one thing to keep in mind is the higher you have your cache, and the more that is currently consumed, the LONGER it will take in the event the reply has to take over… While standby-reply does help to improve takeover times, its not significant if there is a lot of clients with a lot of open caps. We are using in the 40GB cache after ramping up a bit a time to help with recalls. But when I failover now I’m looking at 1-3 minutes, with or without standby-replay enabled. Do some testing with failovers if you have the ability to ensure that your timings are OK, too big can cause issues in that area, that I know of… Robert On Wed, Jun 29, 2022 at 6:54 AM Eugen Block <eblock@xxxxxx> wrote: > Hi, > > you can check how much your MDS is currently using: > > ceph daemon mds.<MDS> cache status > > Does it already scratch your limit? I usually start with lower values > if it's difficult to determine how much it will actually use and > increase it if necessary. > > Zitat von Arnaud M <arnaud.meauzoone@xxxxxxxxx>: > > > Hello to everyone > > > > I have a ceph cluster currently serving cephfs. > > > > The size of the ceph filesystem is around 1 Po. > > 1 Active mds and 1 Standby-replay > > I do not have a lot of cephfs clients for now 5 but it may increase to 20 > > or 30. > > > > Here is some output > > > > Rank | State | Daemon | Activity | Dentries > | > > Inodes | Dirs | Caps > > > > 0 | active | ceph-g-ssd-4-2.mxwjvd | Reqs: 130 /s | 10.2 M > | > > 10.1 M | 356.8 k | 707.6 k > > > > 0-s | standby-replay | ceph-g-ssd-4-1.ixqewp | Evts: 0 /s | 156.5 k > | > > 127.7 k | 47.4 k | 0 > > > > It is working really well > > > > I plan to to increase this cephfs cluster up to 10 Po (for now) and even > > more > > > > What would be the good value for "mds_cache_memory_limit" ? I have set it > > to 80 Gb because I have enough ram on my server to do so. > > > > Was it a good idea ? Or is it counter-productive ? > > > > All the best > > > > Arnaud > > _______________________________________________ > > ceph-users mailing list -- ceph-users@xxxxxxx > > To unsubscribe send an email to ceph-users-leave@xxxxxxx > > > > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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