Hi, Am 01.03.2018 um 09:42 schrieb Dan van der Ster: > 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? Yes the PGs are perfectly distributed - but i think most of the people would like to have a dsitribution by bytes and not pgs. Is this possible? I mean in the code there is already a dict for pgs, objects and bytes - but i don't know how to change the logic. Just remove the pgs and objects from the dict? > 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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