[PVFS2-users] performance

[Dean Hildebrand]

I have a question about some results I'm seeing.  My setup is 3 I/O
nodes (with 1 of them being the MD server) and 4 PVFS2 clients.  The
servers are set to sync.  Version 0.8.0.

My IOzone tests reveal the following write performance results:
Single client throughput: 29MB/s
Two clients aggregate throughput: 39MB/s
>2 clients aggregate throughput: 39MB/s

Any idea why a single client cannot max out the 3 clients?  Using iostat,
I see that the 3 servers are each writing around 20MB/s to disk for a
single client.  I wouldn't expect 60MB/s, but I'm getting half that.  Is
this standard stuff?

Also, a single NFS client exporting ext3 on these machines can achieve a
write throughput of 20MB/s.  Just thought I'd mention as a comparison.

Thanks for any help,
Dean