Hi, How big is your cluster and what is your use case? For us, we'll likely never enable the recent tunables that need to remap *all* PGs -- it would simply be too disruptive for marginal benefit. Cheers, Dan On Thu, Sep 28, 2017 at 9:21 AM, mj <lists@xxxxxxxxxxxxx> wrote: > Hi, > > We have completed the upgrade to jewel, and we set tunables to hammer. > Cluster again HEALTH_OK. :-) > > But now, we would like to proceed in the direction of luminous and bluestore > OSDs, and we would like to ask for some feedback first. > > From the jewel ceph docs on tubables: "Changing tunable to "optimal" on an > existing cluster will result in a very large amount of data movement as > almost every PG mapping is likely to change." > > Given the above, and the fact that we would like to proceed to > luminous/bluestore in the not too far away future: What is cleverer: > > 1 - keep the cluster at tunable hammer now, upgrade to luminous in a little > while, change OSDs to bluestore, and then set tunables to optimal > > or > > 2 - set tunable to optimal now, take the impact of "almost all PG > remapping", and when that is finished, upgrade to luminous, bluestore etc. > > Which route is the preferred one? > > Or is there a third (or fourth?) option..? :-) > > MJ > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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