Hi, Zeros are not a great choice of data for testing a storage system unless you are specifically testing what it does with zeros. Ceph knows that other higher layers in the storage stack use zero-fill for certain things and will probably optimise for it. E.g., it's common for thin-provisioning systems to not actually store runs of 0's (they'll still return them when read). I don't know what Ceph does in this specific case, but I could imagine it allocating relevant space within the RBD object-map, but never bothering to send anything to the actual objects.
Also, note that the description of bluestore_extent_compress is "Sum for extents that have been removed due to compression", so sounds to me like something is working. Perhaps you can provide for detail of the overall stats, cluster config, and whether anything else is stored in it? On Tue, 26 Jun 2018 at 23:53, David Turner <drakonst...@gmail.com> wrote: > ceph daemon osd.1 perf dump | grep bluestore | grep compress > "bluestore_compressed": 0, > "bluestore_compressed_allocated": 0, > "bluestore_compressed_original": 0, > "bluestore_extent_compress": 35372, > > I filled up an RBD in a compressed pool (aggressive) in my test cluster > with 1TB of zeros. The bluestore OSDs in the cluster all show similar to > this. Am I missing something here? Is there any other method to > determining compression ratios? > > On Tue, Dec 5, 2017 at 1:25 AM Rafał Wądołowski < > rwadolow...@cloudferro.com> wrote: > >> Finally, I've founded the command: >> >> >> ceph daemon osd.1 perf dump | grep bluestore >> >> >> And there you have compressed data >> Regards, >> >> Rafał Wądołowski >> >> >> http://cloudferro.com/ >> On 04.12.2017 14:17, Rafał Wądołowski wrote: >> >> Hi, >> >> Is there any command or tool to show effectiveness of bluestore >> compression? >> >> I see the difference (in ceph osd df tree), while uploading a object to >> ceph, but maybe there are more friendly method to do it. >> >> >> >> _______________________________________________ >> 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 > -- Cheers, ~Blairo
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