I am using tiobench to test performance of an NFS mounted volume, and
notice that Sequential Reads are much slower than Random Reads. This
isn't the behavior when I run the same test on the disk mounted
locally.
For random reads I'm getting:
50 MB/s over NFS
v.s
384 MB/s when mounted locally
This is in comparison to the benchmark for _Random Reads_, in which I get:
288 MB/s both over NFS _and_ when directly mounted
The other benchmarks seem to be in line with what I would expect, but
I'm fairly new to NFS. Why would sequential reads over NFS be sooo
much slower than random reads over NFS?
I am exporting the volume on the server like this
/export *.internal(no_subtree_check,rw,no_root_squash)
and mounting with this:
mount -o hard,intr,async,noatime,nodiratime,noacl $NFS_SERVER:/export /nfs
Additionally I am doing all this in amazon EC2, exporting an EBS
volume with the XFS file system (redundant, I know).
I have tried using jumbo frames and various other mount options, but
none seem to have much effect.
Thanks for any clues.
------------------------------------------------------------------------------
Download Intel® Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
_______________________________________________
NFS maillist - NFS@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/nfs
_______________________________________________
Please note that nfs@xxxxxxxxxxxxxxxxxxxxx is being discontinued.
Please subscribe to linux-nfs@xxxxxxxxxxxxxxx instead.
http://vger.kernel.org/vger-lists.html#linux-nfs
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
