At the moment we are running validation on a brand new 3PAR 7400 with 264 x 450GB x 10,000rpm SAS drives in a full 4 node mesh.
This is designed to be our performance storage that backs our primary Oracle and Exchange systems.
What we have noticed is that sequential read is much slower then sequential write, mainly at lower block sizes. Attached is a graph from the 3PAR management console of the particular VV we are testing on.
This is from a server with 4 paths to the 3PAR. There are 2 ports on the server connected to 4 ports on the 3PAR via a 4GB FC fabric.
The test is running 16k blocks from 8 workers in sequential read and then sequential write.
Is this normal behaviour for a 3PAR system? HP refuse to say whether this is expected or not, but tell us that our SAN is correctly configured and show other graphs with much higher trhoughput; e.g. large blocks, random reads and writes etc.
It isn't a "real world" example of our work load but struck as anomalous and worthy of an explanation before we comiisioned it to production.
Any suggestions or explanations?
Thanks,
Dave
Attachment:
File comment: Graph of performance read vs write at 16k blocks with 8 workers.
3parperf.PNG [ 73.12 KiB | Viewed 16408 times ]