On Thu, Mar 1, 2018 at 9:31 AM, Stefan Priebe - Profihost AG <s.priebe@xxxxxxxxxxxx> wrote: > Hi, > Am 01.03.2018 um 09:03 schrieb Dan van der Ster: >> Is the score improving? >> >> ceph balancer eval >> >> It should be decreasing over time as the variances drop toward zero. >> >> You mentioned a crush optimize code at the beginning... how did that >> leave your cluster? The mgr balancer assumes that the crush weight of >> each OSD is equal to its size in TB. >> Do you have any osd reweights? crush-compat will gradually adjust >> those back to 1.0. > > I reweighted them all back to their correct weight. > > Now the mgr balancer module says: > mgr[balancer] Failed to find further optimization, score 0.010646 > > But as you can see it's heavily imbalanced: > > > Example: > 49 ssd 0.84000 1.00000 864G 546G 317G 63.26 1.13 49 > > vs: > > 48 ssd 0.84000 1.00000 864G 397G 467G 45.96 0.82 49 > > 45% usage vs. 63% Ahh... but look, the num PGs are perfectly balanced, which implies that you have a relatively large number of empty PGs. But regardless, this is annoying and I expect lots of operators to get this result. (I've also observed that the num PGs is gets balanced perfectly at the expense of the other score metrics.) I was thinking of a patch around here [1] that lets operators add a score weight on pgs, objects, bytes so we can balance how we like. Spandan: you were the last to look at this function. Do you think it can be improved as I suggested? Cheers, Dan [1] https://github.com/ceph/ceph/blob/luminous/src/pybind/mgr/balancer/module.py#L558 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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