cephfs speed

[Peter Eisch <Peter.Eisch@xxxxxxxxxxxxxxx>]

Hi,

I have a cluster serving cephfs and it works. It’s just slow. Client is using the kernel driver. I can ‘rados bench’ writes to the cephfs_data pool at wire speeds (9580Mb/s on a 10G link) but when I copy data into cephfs it is rare to get above 100Mb/s. Large file writes may start fast (2Gb/s) but within a minute slows. In the dashboard at the OSDs I get lots of triangles (it doesn't stream) which seems to be lots of starts and stops. By contrast the graphs show constant flow when using 'rados bench.'

I feel like I'm missing something obvious. What can I do to help diagnose this better or resolve the issue?

Errata:
Version: 12.2.7 (on everything)
mon: 3 daemons, quorum cephmon-s01,cephmon-s03,cephmon-s02
mgr: cephmon-s02(active), standbys: cephmon-s01, cephmon-s03
mds: cephfs1-1/1/1 up {0=cephmon-s02=up:active}, 2 up:standby
osd: 70 osds: 70 up, 70 in
rgw: 3 daemons active

rados bench summary:
Total time run: 600.043733
Total writes made: 167725
Write size: 4194304
Object size: 4194304
Bandwidth (MB/sec): 1118.09
Stddev Bandwidth: 7.23868
Max bandwidth (MB/sec): 1140
Min bandwidth (MB/sec): 1084
Average IOPS: 279
Stddev IOPS: 1
Max IOPS: 285
Min IOPS: 271
Average Latency(s): 0.057239
Stddev Latency(s): 0.0354817
Max latency(s): 0.367037
Min latency(s): 0.0120791

peter

Peter Eisch​

virginpulse.com

|

globalchallenge.virginpulse.com

Australia | Bosnia and Herzegovina | Brazil | Canada | Singapore | Switzerland | United Kingdom | USA

Confidentiality Notice: The information contained in this e-mail, including any attachment(s), is intended solely for use by the designated recipient(s). Unauthorized use, dissemination, distribution, or reproduction of this message by anyone other than the intended recipient(s), or a person designated as responsible for delivering such messages to the intended recipient, is strictly prohibited and may be unlawful. This e-mail may contain proprietary, confidential or privileged information. Any views or opinions expressed are solely those of the author and do not necessarily represent those of Virgin Pulse, Inc. If you have received this message in error, or are not the named recipient(s), please immediately notify the sender and delete this e-mail message.

v2.10

_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com