> -----Original Message----- > From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of > Daleep Bais > Sent: 09 September 2015 09:18 > To: Ceph-User <ceph-users@xxxxxxxx> > Subject: Poor IOPS performance with Ceph > > Hi, > > I have made a test ceph cluster of 6 OSD's and 03 MON. I am testing the read > write performance for the test cluster and the read IOPS is poor. > When I individually test it for each HDD, I get good performance, whereas, > when I test it for ceph cluster, it is poor. Can you give any further details about your cluster. Are your HDD's backed by SSD journals? > > Between nodes, using iperf, I get good bandwidth. > > My cluster info : > > root@ceph-node3:~# ceph --version > ceph version 9.0.2-752-g64d37b7 > (64d37b70a687eb63edf69a91196bb124651da210) > root@ceph-node3:~# ceph -s > cluster 9654468b-5c78-44b9-9711-4a7c4455c480 > health HEALTH_OK > monmap e9: 3 mons at {ceph-node10=192.168.1.210:6789/0,ceph- > node17=192.168.1.217:6789/0,ceph-node3=192.168.1.203:6789/0} > election epoch 442, quorum 0,1,2 ceph-node3,ceph-node10,ceph- > node17 > osdmap e1850: 6 osds: 6 up, 6 in > pgmap v17400: 256 pgs, 2 pools, 9274 MB data, 2330 objects > 9624 MB used, 5384 GB / 5394 GB avail > 256 active+clean > > > I have mapped an RBD block device to client machine (Ubuntu 14) and from > there, when I run tests using FIO, i get good write IOPS, however, read is > poor comparatively. > > Write IOPS : 44618 approx > > Read IOPS : 7356 approx 1st thing that strikes me is that your numbers are too good, unless these are actually SSD's and not spinning HDD's? I would expect to get around a max of 600 read IOPs for 6x 7.2k disks, so I guess either you are hitting the page cache on the OSD node(s) or the librbd cache. The writes are even higher, are you using the "direct=1" option in the Fio job? > > Pool replica - single > pool 1 'test1' replicated size 1 min_size 1 > > I have implemented rbd_readahead in my ceph conf file also. > Any suggestions in this regard with help me.. > > Thanks. > > Daleep Singh Bais _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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