On Sat, 4 Nov 2006, Peter J. Braam wrote:
Do you have a test on which NFS performs much better. We'd like to know more about that.
One test I can mention is postmark, originally written by Netapp folks, now available from Debian:
http://packages.debian.org/stable/utils/postmarkIn the test, postmark was configured to perform 10k "transactions" on 10k files between 500B and 22kB.
This was run with up to 16 processes on *one* client connecting to various server configs on several interconnects and storage systems, running 1.4.6 and 1.6beta4.
For convenience, I wrote the attached wrapper script: $ ssh $client postmark.sh -n 10000 -t 10000 -j $numprocs > $logThe metric was the number of transactions per second (sum of column 3 across all lines of $log). NFS reached 800-1000 t/s with 2-8 processes (then performance dropped) over GigE, while Lustre peaked at 200 t/s with 2 process on a tiny GigE cluster (1 MDS, 1 OSS serving 1 OST). A bigger cluster could not give more than 900 t/s.
Back then I suspected that the test was probably network bound (because of high interrupt and packet rates vs. low CPU and disk usage), but I could not find a good measurement. A tool showing metadata RPC statistics (such as LMT maybe, but I didn't know it then) would have been useful.
If you go bak on this list, you will see that Lustre can handsomely beat NFS at unpacking archives, for example. So I am curious.
I suppose you refer to the thread "I/O performance on small files" (end of June). IIRC the recipes mentioned there had been used in the tests.
Now I no longer have time to spend on these issues, but ideas for improvement would still be interesting.
-- Jean-Marc Saffroy - [EMAIL PROTECTED]
postmark.sh
Description: Bourne shell script
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