That does make sense and I wish it were true however what I'm seeing doesn't support your hypothesis. I've had several drives die and be replaced since the go-live date and I'm actually in the home stretch on reducing the pg_num on that pool so pretty much every PG has already been moved several times over. It's also possible that my method for checking compression is flawed. Spot checks from what I can see in an OSD stat dump and ceph df detail seem to line up so I don't believe this is the case. The only time I see the counters move is when someone puts new data in via globus or migration from a cluster job. I will test what you proposed though by draining an OSD and refilling it then checking the stat dump to see what lives under compression and what does not. -paul -- Paul Mezzanini Sr Systems Administrator / Engineer, Research Computing Information & Technology Services Finance & Administration Rochester Institute of Technology o:(585) 475-3245 | pfmeec@xxxxxxx CONFIDENTIALITY NOTE: The information transmitted, including attachments, is intended only for the person(s) or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and destroy any copies of this information. ------------------------ ________________________________________ Just my two cents: Compression is an OSD level operation, and the OSD involved in a PG do no know about each others' compression settings. And they probably also do not care, considering the OSD to be a black box. I would propose to drain OSDs (one by one or host by host by setting osd weights) to move the uncompressed data off. Reset the weights to the former values later to move the data back, and upon writing the data it should be compressed. Compression should also happen during writing the data to other osds when it is moved an OSD, but you will end up with a mix of compressed and uncompressed data on the same OSD. You will have to process all OSDs). If this is working as expected, you do not have to touch the data on the filesystem level at all. The operation happens solely on the underlying storage. Regards, Burkhard _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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