[ceph-users] Re: "optimal" tunables on release upgrade

Hi Matthew, my colleagues and I can still remember that the values do not change automatically when you upgrade. I remember performance problems after an upgrade with old tunables a few years ago. But such behaviour may change with the next version. Meanwhile you get a warning in ceph status if they are not set correctly. https://docs.ceph.com/en/latest/rados/operations/health-checks/#old-crush-t… Regards, Joachim ___________________________________ Clyso GmbH - Ceph Foundation Member support(a)clyso.com https://www.clyso.com Am 26.02.2021 um 15:52 schrieb Matthew Vernon: > Hi, > > Having been slightly caught out by tunables on my Octopus upgrade[0], > can I just check that if I do > ceph osd crush tunables optimal > > That will update the tunables on the cluster to the current "optimal" > values (and move a lot of data around), but that this doesn't mean > they'll change next time I upgrade the cluster or anything like that? > > It's not quite clear from the documentation whether the next time > "optimal" tunables change that'll be applied to a cluster where I've > set tunables thus, or if tunables are only ever changed by a fresh > invocation of ceph osd crush tunables... > > [I assume the same answer applies to "default"?] > > Regards, > > Matthew > > [0] I foolishly thought a cluster initially installed as Jewel would > have jewel tunables > >