On Thu, 1 Dec 2016 18:06:38 -0600 Reed Dier wrote: > Apologies if this has been asked dozens of times before, but most answers are > from pre-Jewel days, and want to double check that the methodology still > holds. > It does.
> Currently have 16 OSD’s across 8 machines with on-disk journals, created > using ceph-deploy. > > These machines have NVMe storage (Intel P3600 series) for the system volume, > and am thinking about carving out a partition for SSD journals for the OSD’s. > The drives don’t make tons of use of the local storage, so should have plenty > of io overhead to support the OSD journaling, as well as the P3600 should > have the endurance to handle the added write wear. > Slight disconnect there, money for a NVMe (which size?) and on disk journals? ^_- > From what I’ve read, you need a partition per OSD journal, so with the > probability of a third (and final) OSD being added to each node, I should > create 3 partitions, each ~8GB in size (is this a good value? 8TB OSD’s, is > the journal size based on size of data or number of objects, or something > else?). > Journal size is unrelated to the OSD per se, with default parameters and HDDs for OSDs a size of 10GB would be more than adequate, the default of 5GB would do as well. > So: > {create partitions} > set noout > service ceph stop osd.$i > ceph-osd -i osd.$i —flush-journal > rm -f rm -f /var/lib/ceph/osd/<osd-id>/journal Typo and there should be no need for -f. ^_^ > ln -s /var/lib/ceph/osd/<osd-id>/journal /dev/<ssd-partition-for-journal> Even though in your case with a single(?) NVMe there is little chance for confusion, ALWAYS reference to devices by their UUID or similar, I prefer the ID: --- lrwxrwxrwx 1 root root 44 May 21 2015 journal -> /dev/disk/by-id/wwn-0x55cd2e404b73d570-part4 --- > ceph-osd -i osd.$i -mkjournal > service ceph start osd.$i > ceph osd unset noout > > Does this logic appear to hold up? > Yup. Christian > Appreciate the help. > > Thanks, > > Reed -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com