> -----Original Message----- > From: Vitaliy Filippov <vita...@yourcmc.ru> > Sent: 23 February 2019 20:31 > To: n...@fisk.me.uk; Serkan Çoban <cobanser...@gmail.com> > Cc: ceph-users <ceph-users@lists.ceph.com> > Subject: Re: [ceph-users] [Bluestore] Some of my osd's uses BlueFS slow > storage for db - why? > > X-Assp-URIBL failed: 'yourcmc.ru'(black.uribl.com ) > X-Assp-Spam-Level: ***** > X-Assp-Envelope-From: vita...@yourcmc.ru > X-Assp-Intended-For: n...@fisk.me.uk > X-Assp-ID: ASSP.fisk.me.uk (55095-04241) > X-Assp-Version: 1.9.1.4(1.0.00) > > Numbers are easy to calculate from RocksDB parameters, however I also don't > understand why it's 3 -> 30 -> 300... > > Default memtables are 256 MB, there are 4 of them, so L0 should be 1 GB, > L1 should be 10 GB, and L2 should be 100 GB?
From how I understand it, RocksDB levels increment by a factor of x10: 256MB+2.56GB+25.6GB=~28-29GB Although that is greatly simplified way of looking at it, this link explains it in more detail: https://github.com/facebook/rocksdb/wiki/Leveled-Compaction > > >>> These sizes are roughly 3GB,30GB,300GB. Anything in-between those > >>> sizes are pointless. Only ~3GB of SSD will ever be used out of a > > 28GB partition. Likewise a 240GB partition is also pointless as only > > ~30GB will be used. > > > > Where did you get those numbers? I would like to read more if you can > > point to a link. > > -- > With best regards, > Vitaliy Filippov _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
