Hi Swami, That's a known issue, which I believe is much improved in Jewel thanks to a priority queue added somewhere in the OSD op path (I think). If I were you I'd be planning to get off Firefly and upgrade. Cheers, On 10 June 2016 at 12:08, M Ranga Swami Reddy <swamireddy@xxxxxxxxx> wrote: > Blair - Thanks for the details. I used to set the low priority for > recovery during the rebalance/recovery activity. > Even though I set the recovery_priority as 5 (instead of 1) and > client-op_priority set as 63, some of my customers complained that > their VMs are not reachable for a few mins/secs during the reblancing > task. Not sure, these low priority configurations are doing the job as > its. > > Thanks > Swami > > On Thu, Jun 9, 2016 at 5:50 PM, Blair Bethwaite > <blair.bethwaite@xxxxxxxxx> wrote: >> Swami, >> >> Run it with the help option for more context: >> "./crush-reweight-by-utilization.py --help". In your example below >> it's reporting to you what changes it would make to your OSD reweight >> values based on the default option settings (because you didn't >> specify any options). To make the script actually apply those weight >> changes you need the "-d -r" or "--doit --really" flags. >> >> If you want to get an idea of the impact that the weight changes will >> have before actually starting to move data then I suggest setting >> norecover and nobackfill (ceph osd set ...) on your cluster before >> making the weight changes, you can then examine "ceph -s" output >> (looking at "objects misplaced" to determine the scale of recovery >> required. Unset the flags once ready to start or back-out the reweight >> settings if you change your mind. You'll also want to lower these >> recovery and backfill tunables to reduce impact to client I/O (and if >> possible do not do this reweight change during peak I/O hours): >> ceph tell osd.* injectargs '--osd-max-backfills 1' >> ceph tell osd.* injectargs '--osd-max-recovery-threads 1' >> ceph tell osd.* injectargs '--osd-recovery-op-priority 1' >> ceph tell osd.* injectargs '--osd-client-op-priority 63' >> ceph tell osd.* injectargs '--osd-recovery-max-active 1' >> >> Cheers, >> >> On 9 June 2016 at 20:20, M Ranga Swami Reddy <swamireddy@xxxxxxxxx> wrote: >>> Hi Blari, >>> I ran the script and results are below: >>> == >>> ./crush-reweight-by-utilization.py >>> average_util: 0.587024, overload_util: 0.704429, underload_util: 0.587024. >>> reweighted: >>> 43 (0.852690 >= 0.704429) [1.000000 -> 0.950000] >>> 238 (0.845154 >= 0.704429) [1.000000 -> 0.950000] >>> 104 (0.827908 >= 0.704429) [1.000000 -> 0.950000] >>> 173 (0.817063 >= 0.704429) [1.000000 -> 0.950000] >>> == >>> >>> is the above scripts says to reweight 43 -> 0.95? >>> >>> Thanks >>> Swami >>> >>> On Wed, Jun 8, 2016 at 10:34 AM, M Ranga Swami Reddy >>> <swamireddy@xxxxxxxxx> wrote: >>>> Blair - Thanks for the script...Btw, is this script has option for dry run? >>>> >>>> Thanks >>>> Swami >>>> >>>> On Wed, Jun 8, 2016 at 6:35 AM, Blair Bethwaite >>>> <blair.bethwaite@xxxxxxxxx> wrote: >>>>> Swami, >>>>> >>>>> Try https://github.com/cernceph/ceph-scripts/blob/master/tools/crush-reweight-by-utilization.py, >>>>> that'll work with Firefly and allow you to only tune down weight of a >>>>> specific number of overfull OSDs. >>>>> >>>>> Cheers, >>>>> >>>>> On 7 June 2016 at 23:11, M Ranga Swami Reddy <swamireddy@xxxxxxxxx> wrote: >>>>>> OK, understood... >>>>>> To fix the nearfull warn, I am reducing the weight of a specific OSD, >>>>>> which filled >85%.. >>>>>> Is this work-around advisable? >>>>>> >>>>>> Thanks >>>>>> Swami >>>>>> >>>>>> On Tue, Jun 7, 2016 at 6:37 PM, Sage Weil <sage@xxxxxxxxxxxx> wrote: >>>>>>> On Tue, 7 Jun 2016, M Ranga Swami Reddy wrote: >>>>>>>> Hi Sage, >>>>>>>> >Jewel and the latest hammer point release have an improved >>>>>>>> >reweight-by-utilization (ceph osd test-reweight-by-utilization ... to dry >>>>>>>> > run) to correct this. >>>>>>>> >>>>>>>> Thank you....But not planning to upgrade the cluster soon. >>>>>>>> So, in this case - are there any tunable options will help? like >>>>>>>> "crush tunable optimal" or so? >>>>>>>> OR any other configuration options change will help? >>>>>>> >>>>>>> Firefly also has reweight-by-utilization... it's just a bit less friendly >>>>>>> than the newer versions. CRUSH tunables don't generally help here unless >>>>>>> you have lots of OSDs that are down+out. >>>>>>> >>>>>>> Note that firefly is no longer supported. >>>>>>> >>>>>>> sage >>>>>>> >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Thanks >>>>>>>> Swami >>>>>>>> >>>>>>>> >>>>>>>> On Tue, Jun 7, 2016 at 6:00 PM, Sage Weil <sage@xxxxxxxxxxxx> wrote: >>>>>>>> > On Tue, 7 Jun 2016, M Ranga Swami Reddy wrote: >>>>>>>> >> Hello, >>>>>>>> >> I have aorund 100 OSDs in my ceph cluster. In this a few OSDs filled >>>>>>>> >> with >85% of data and few OSDs filled with ~60%-70% of data. >>>>>>>> >> >>>>>>>> >> Any reason why the unevenly OSDs filling happned? do I need to any >>>>>>>> >> tweaks on configuration to fix the above? Please advise. >>>>>>>> >> >>>>>>>> >> PS: Ceph version is - 0.80.7 >>>>>>>> > >>>>>>>> > Jewel and the latest hammer point release have an improved >>>>>>>> > reweight-by-utilization (ceph osd test-reweight-by-utilization ... to dry >>>>>>>> > run) to correct this. >>>>>>>> > >>>>>>>> > sage >>>>>>>> > >>>>>>>> -- >>>>>>>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >>>>>>>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>>>>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>>>>>>> >>>>>>>> >>>>>> -- >>>>>> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in >>>>>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>>>> >>>>> >>>>> >>>>> -- >>>>> Cheers, >>>>> ~Blairo >> >> >> >> -- >> Cheers, >> ~Blairo -- Cheers, ~Blairo _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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