2017-01-04 23:52 GMT+08:00 Mike Miller <millermike...@gmail.com>: > Wido, all, > > can you point me to the "recent benchmarks" so I can have a look? > How do you define "performance"? I would not expect cephFS throughput to > change, but it is surprising to me that metadata on SSD will have no > measurable effect on latency. > > - mike > > operations like "ls", "stat", "find" would become faster, the bottleneck is the slow osds which store file data.
> > On 1/3/17 10:49 AM, Wido den Hollander wrote: > >> >> Op 3 januari 2017 om 2:49 schreef Mike Miller <millermike...@gmail.com>: >>> >>> >>> will metadata on SSD improve latency significantly? >>> >>> >> No, as I said in my previous e-mail, recent benchmarks showed that >> storing CephFS metadata on SSD does not improve performance. >> >> It still might be good to do since it's not that much data thus recovery >> will go quickly, but don't expect a CephFS performance improvement. >> >> Wido >> >> Mike >>> >>> On 1/2/17 11:50 AM, Wido den Hollander wrote: >>> >>>> >>>> Op 2 januari 2017 om 10:33 schreef Shinobu Kinjo <ski...@redhat.com>: >>>>> >>>>> >>>>> I've never done migration of cephfs_metadata from spindle disks to >>>>> ssds. But logically you could achieve this through 2 phases. >>>>> >>>>> #1 Configure CRUSH rule including spindle disks and ssds >>>>> #2 Configure CRUSH rule for just pointing to ssds >>>>> * This would cause massive data shuffling. >>>>> >>>> >>>> Not really, usually the CephFS metadata isn't that much data. >>>> >>>> Recent benchmarks (can't find them now) show that storing CephFS >>>> metadata on SSD doesn't really improve performance though. >>>> >>>> Wido >>>> >>>> >>>>> >>>>> On Mon, Jan 2, 2017 at 2:36 PM, Mike Miller <millermike...@gmail.com> >>>>> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> Happy New Year! >>>>>> >>>>>> Can anyone point me to specific walkthrough / howto instructions how >>>>>> to move >>>>>> cephfs metadata to SSD in a running cluster? >>>>>> >>>>>> How is crush to be modified step by step such that the metadata >>>>>> migrate to >>>>>> SSD? >>>>>> >>>>>> Thanks and regards, >>>>>> >>>>>> Mike >>>>>> _______________________________________________ >>>>>> ceph-users mailing list >>>>>> ceph-users@lists.ceph.com >>>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>>>>> >>>>> _______________________________________________ >>>>> ceph-users mailing list >>>>> ceph-users@lists.ceph.com >>>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>>>> >>>> _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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