Presently running version 5.0.DB49000000.3278

I have a bit of discrepancy in FC read performance when compared to write performance. I setup a single FC target using a QLA2462. The backend storage is a 3ware 9650SE card with 12 SATA 750GB drives in a 12 drive RAID 5 with 256k Chunk. The initiator (Cent OS 5.2) saw the target as a disk without issue.

I began doing some performance testing using dd;

time dd if=/dev/zero of=/dev/sdb bs=1M count=16384 for writes

time dd if=/dev/sdb of=/dev/null bs=1M count=16384 for reads

basically reading and writing a 16GB file

I ran each 10 times my average read performance was 142.2 MB/s however write performance was 394 MB/s. Note this is raw device performance, no filesystem.

After noting this i created a file system (ext3), mounted the drive, and re-ran the tests

time dd if=/dev/zero of=/mnt/opene/testfile bs=1M count=16384 for writes

time dd if=/mnt/opene/testfile of=/dev/null bs=1M count=16384 for reads

This time my average read was 166 MB/s but my write performance dropped to 222.7 MB/s.

Anyone else see this kind of weird performance using FC target?

thanks!