On Wed, Jul 10, 2013 at 1:16 AM, Gandalf Corvotempesta <gandalf.corvotempe...@gmail.com> wrote: > Hi, > i'm planning a new cluster on a 10GbE network. > Each storage node will have a maximum of 12 SATA disks and 2 SSD as journals. > > What do you suggest as journal size for each OSD? 5GB is enough? > Should I just consider SATA writing speed when calculating journal > size or also network speed?
Hello, As many recommendations suggests before, you may set journal size proportional to amount of median (or peak, if expected) writes multiplied, say, by thirty seconds - that`s the safe area and you should not able to suffer because of journal size following this calculation. Twelve SATA disks in theory may have enough output to thrash 10G network but you`ll face lack of IOPS times before almost for sure, and OSD daemons are not working very close to the physical limits speaking of transferring data from/to disk, so fine tuning of spinning storage media still is primary target to play with in such configuration. > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
