Wed, 4 Sep 2019 10:32:56 +0200 Yoann Moulin <yoann.moulin@xxxxxxx> ==> ceph-users@xxxxxxx : > Hello, > > > Tue, 3 Sep 2019 11:28:20 +0200 > > Yoann Moulin <yoann.moulin@xxxxxxx> ==> ceph-users@xxxxxxx : > >> Is it better to put all WAL on one SSD and all DBs on the other one? Or put WAL and DB of the first 5 OSDs on the first SSD and the 5 others on > >> the second one. > > > > I don't know if this has a relevant impact on the latency/speed of the ceph system but we use LVM on top of a SW RAID 1 over two SSDs for WAL & DB on this RAID1. > > What is the recommended size for wall and db in my case? > > I have : > > 10x 6TB Disk OSDs (data) > 2x 480G SSD > > Best, I'm still unsure with the size of the block.db and the wal. This seems to be relevant: http://lists.ceph.com/pipermail/ceph-users-ceph.com/2019-May/035086.html But it is also said that the pure WAL need just 1 GB of space. http://lists.ceph.com/pipermail/ceph-users-ceph.com/2019-August/036509.html So the conclusion would be to use 2*X(DB) + 1GB (WAL) if you put both on the same partition/LV. With X being on of 3GB, 30GB or 300GB. You have 10 OSDs. That means you should have 10 partitions/LVs for DBs & WALs. This is something that should be cleared up in the docs! Lars _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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