Hi, maybe you remember this line in my long report: > bluestore_compression_min_blob_size_ssd = 8192 *** Dang! *** To fix the issues with settings on our cluster, I plan to change the bluestore_compression_min_blob_size_ssd and also disable compression on pools that are accidentally compressed due to bluestore settings, but shouldn't. This is the plan: ceph config set osd bluestore_compression_min_blob_size_ssd = 65536 ceph osd pool set sr-rbd-meta-one compression_mode none ceph osd pool set con-fs2-meta1 compression_mode none ceph osd pool set con-fs2-meta2 compression_mode none ceph osd pool set sr-rbd-data-one-perf compression_mode none To be absolutely sure, could you please confirm that these changes can be executed at run time on a system that has data on it? Thanks a lot! ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Frank Schilder Sent: 31 August 2022 11:32 To: Mark Nelson; ceph-users@xxxxxxx Cc: Adam Kupczyk Subject: Re: Request for Info: bluestore_compression_mode? Hi Mark, I need a bit more time for replying. I just wanted to add a few observations and correct some mistakes in my earlier communication. - There are actually 5 different settings, NULL (=unset), none, passive, aggressive and force. These can be set on OSDs and pools. In addition, the blob-size arguments for compression are also available on pools. This gets really confusing and it is not fully documented which settings will take precedence. - In Octopus it seems that the interaction of combinations of OSD- and pool settings has been fixed (at least the case where one of these is NULL). This was a mess in mimic. Its still not clear from the documentation what takes precedence in all possible situations of conflicts. My personal take is that pool-setings are sufficient, the OSD settings could be removed and the mode options could be reduced to none and force, where NULL=none (none is default). As promised, I will return to this in another thread about the small files/tail object handling that will also consider compression. Best regards, ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
 |