On Wed, Jul 17, 2013 at 08:59:43AM +0200, Kasper Dieter wrote: > Hi Xiaoxi, Wheats, > > you hit the right point: We are looking for an Enterprise Linux distribution > as base for Ceph. > RHEL and CentOS has a very broad distribution and a high acceptance in the > Data Center due to our observation. > > The pain of this distro (from Ceph point of view) is the old kernel. > As you know a 'new' kernel ( >= 3.6) is mandatory for stability and features > of the Kernel CephFS and RBD (and btrfs). > > So, we decided to use a very stable distro (CentOS-6.4) and combine it with a > new, but mature/stable kernel (3.8.13). > > I'm running fedora on my Laptop: > Linux oder 3.9.9-301.fc19.x86_64 #1 SMP Thu Jul 4 15:10:36 UTC 2013 x86_64 > x86_64 x86_64 GNU/Linux > but as you said it is "too aggressive". > Another aspect might be our good knowledge on RHEL and small experience with > Ubuntu. > > It is our goal to run all three presentation layers Block/File/Object in one > Ceph cluster. > We have good experience with block and file and also the performance looks > quit well: > > [root@rx37-4 ~]# ceph osd dump | grep SAS-group-2 > pool 5 'SAS-group-2' rep size 2 min_size 1 crush_ruleset 4 object_hash > rjenkins pg_num 3300 pgp_num 3300 last_change 306 owner 0 > > [root@rx37-2 cephfs]# dd if=/dev/zero of=/mnt/cephfs/sas-pool-5/file1 > bs=4194304 count=10240 > 10240+0 records in > 10240+0 records out > 42949672960 bytes (43 GB) copied, 23.8877 s, 1.8 GB/s >
You were just testing memory performance, no? You can try append 'oflag=direct,sync' or 'oflag=direct' to your dd. This will give you real speed. Thanks Yuan _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
