dhildebz at eecs.umich.edu
Mon Nov 1 15:53:46 EST 2004
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,
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