Hello All, I was comparing the performance of different GlusterFS clients with each other and came across an interesting result. I used fsync tester utility ( here <https://oss.oracle.com/~mason/fsync-tester.c> or here <https://github.com/gregsfortytwo/fsync-tester>) which basically writes 1MB to a file (same file, same offset and same size) and calls fsync on that file and measures the time for fsync( only fsync time, write time is calculated separately). It repeats the same scenario every 1 seconds. I tried fsync tester with GlusterFS fuse client, GlusterFS NFS, and my own filesystem which is also a fuse based file system and uses GlusterFS libgfapi under the hood to store data. I collected 1000 data points (latency) for each client and the result is attached to this email. It's interesting that libgfapi performs almost 3 times better than FUSE and NFS clients. On the other hand FUSE client of GlusterFS has a very high jitter compared to the libgfapi and NFS. Can anyone explain or comment about these results? Thanks a lot, -- Behrooz -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20150428/f1ffb819/attachment.html> -------------- next part -------------- A non-text attachment was scrubbed... Name: fsysnTester.png Type: image/png Size: 27492 bytes Desc: not available URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20150428/f1ffb819/attachment.png>