May I ask why are you using EL repo with centos? AFAIK, Redhat is backporting all ceph features to 3.10 kernels. Am I wrong?
On Fri, Feb 2, 2018 at 2:44 PM, Richard Hesketh <richard.hesk...@rd.bbc.co.uk> wrote: > On 02/02/18 08:33, Kevin Olbrich wrote: >> Hi! >> >> I am planning a new Flash-based cluster. In the past we used SAMSUNG PM863a >> 480G as journal drives in our HDD cluster. >> After a lot of tests with luminous and bluestore on HDD clusters, we plan to >> re-deploy our whole RBD pool (OpenNebula cloud) using these disks. >> >> As far as I understand, it would be best to skip journaling / WAL and just >> deploy every OSD 1-by-1. This would have the following pro's (correct me, if >> I am wrong): >> - maximum performance as the journal is spread accross all devices >> - a lost drive does not affect any other drive >> >> Currently we are on CentOS 7 with elrepo 4.4.x-kernel. We plan to migrate to >> Ubuntu 16.04.3 with HWE (kernel 4.10). >> Clients will be Fedora 27 + OpenNebula. >> >> Any comments? >> >> Thank you. >> >> Kind regards, >> Kevin > > There is only a real advantage to separating the DB/WAL from the main data if > they're going to be hosted on a device which is appreciably faster than the > main storage. Since you're going all SSD, it makes sense to deploy each OSD > all-in-one; as you say, you don't bottleneck on any one disk, and it also > offers you more maintenance flexibility as you will be able to easily move > OSDs between hosts if required. If you wanted to start pushing performance > more, you'd be looking at putting NVMe disks in your hosts for DB/WAL. > > FYI, the 16.04 HWE kernel has currently rolled on over to 4.13. > > Rich > > > _______________________________________________ > 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
