On Mon, Aug 8, 2016 at 5:14 PM, Goncalo Borges <goncalo.borges@xxxxxxxxxxxxx> wrote: > Thanks for replying Greg. > > I am trying to figure oout what parameters should I tune to mitigate the > impact of the data movement. For now, I've set > > osd max backfills = 1 > > Are there others you think we should set? > > What do you reckon? That is generally the big one, but I think you'll need advice from people who actually run clusters to see if there's anything more that's useful. :) -Greg > > Cheers > > Goncalo > > > On 08/09/2016 09:26 AM, Gregory Farnum wrote: >> >> On Thu, Aug 4, 2016 at 8:57 PM, Goncalo Borges >> <goncalo.borges@xxxxxxxxxxxxx> wrote: >>> >>> Dear cephers... >>> >>> I am looking for some advice on migrating from legacy tunables to Jewel >>> tunables. >>> >>> What would be the best strategy? >>> >>> 1) A step by step approach? >>> - starting with the transition from bobtail to firefly (and, in this >>> particular step, by starting to set setting chooseleaf_vary_r=5 and then >>> decrease it slowly to 1?) >>> - then from firefly to hammer >>> - then from hammer to jewel >>> >>> 2) or going directly to jewel tunables? >>> >>> Any advise on how to minimize the data movement? >> >> If you're switching tunables, there's going to be a ton of movement >> and you need to prepare for it. But unlike with reweighting, there >> isn't really a way to do it incrementally. I don't know if we have >> experimental evidence but stepping through them is very unlikely to >> help; I think you just want to pick the least bad time for a bunch of >> migration and enable jewel tunables directly. >> -Greg > > > -- > Goncalo Borges > Research Computing > ARC Centre of Excellence for Particle Physics at the Terascale > School of Physics A28 | University of Sydney, NSW 2006 > T: +61 2 93511937 > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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