On Thu, Feb 16, 2017 at 3:51 PM, Blair Bethwaite <blair.bethwaite at gmail.com> wrote: > Hi Brian, > > After another hour of staring at the decompiled crushmap and playing around > with crushtool command lines I finally looked harder at your command line > and noticed I was also specifying "--simulate", removing that gives me > mappings that make much more sense (at least for the existing production > ruleset that I know actually work on the cluster)! So, thanks! > > This looks like the same problem that Robert ran into some time ago: > https://www.spinics.net/lists/ceph-users/msg16950.html, where I believe he > filed a bug (http://tracker.ceph.com/issues/11224) that was rather > unhelpfully rejected with no explanation. I'm going to update that now. > Would be great to get an explanation of what that damned simulate flag is > supposed to do, the documentation for crushtool is somewhat thin on the > subject. Heh. You're right of course. Best as I remember, --simulate is designed to generate an actually random placement of the PGs so a user can do statistical comparisons between that and the CRUSH output to measure quality of balance, etc. This was a project by a summer intern many years ago and I'm not sure anybody knows how to use it properly any more, and I wouldn't expect that flag to interact well with...anything else? -Greg > > Cheers, > > On 17 February 2017 at 05:56, Brian Andrus <brian.andrus at dreamhost.com> > wrote: >> >> v10.2.5 - crushtool working fine to show rack mappings. How are you >> running the command? Get some sleep! ha. >> >> crushtool -i /tmp/crush.map --test --ruleset 3 --num-rep 3 --show-mappings >> >> rule byrack { >> ruleset 3 >> type replicated >> min_size 1 >> max_size 10 >> step take default >> step chooseleaf firstn 0 type rack >> step emit >> } >> >> >> On Thu, Feb 16, 2017 at 7:10 AM, Blair Bethwaite >> <blair.bethwaite at gmail.com> wrote: >>> >>> Am I going nuts (it is extremely late/early here), or is crushtool >>> totally broken? I'm trying to configure a ruleset that will place >>> exactly one replica into three different racks (under each of which >>> there are 8-10 hosts). crushtool has given me empty mappings for just >>> about every rule I've tried that wasn't just the simplest: chooseleaf >>> 0 host. Suspecting something was up with crushtool I have now tried to >>> verify correctness on an existing rule and it is including OSDs in the >>> result mappings that are not even in this hierarchy... >>> >>> (this is on a 10.2.2 install) >>> >>> -- >>> Cheers, >>> ~Blairo >>> _______________________________________________ >>> ceph-users mailing list >>> ceph-users at lists.ceph.com >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> >> >> >> >> -- >> Brian Andrus | Cloud Systems Engineer | DreamHost >> brian.andrus at DreamHost.com | www.dreamhost.com > > > > > -- > Cheers, > ~Blairo > > _______________________________________________ > ceph-users mailing list > ceph-users at lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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