Hello, I don't have anything running Jewel yet, so this is for devs and people who have played with bluestore or read the code. With filestore, Ceph benefits from ample RAM, both in terms of pagecache for reads of hot objects and SLAB to keep all the dir-entries and inodes in memory. With bluestore not being a FS, I'm wondering what can and will be done for it to maximize performance by using available RAM. I doubt there's a dynamic cache allocation ala pagecache present or on the road-map. But how about parameters to grow caches (are there any?) and give the DB more breathing space? I suppose this also cuts into the current inability to do read-ahead with bluestore by itself (not client driven). The underlying reason for this of course to future proof OSD storage servers, any journal SSDs will be beneficial for RocksDB and WAL as well, but if available memory can't be utilized beyond what the OSDs need themselves it makes little sense to put extra RAM into them. Christian -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |