I am running into an issue performance tuning a SAN. I am testing 24 mount points that are RAID - 5 on an EMC DMX with SQLIO. The host I am testing on has 256GB of RAM and 32 cores.
I am using a Param file in my command line which looks like this:
M:\ASRS\ASRS_SQLData01A\testfile.dat 8 0x0 6000
M:\ASRS\ASRS_SQLData02\testfile.dat 8 0x0 6000
M:\ASRS\ASRS_SQLData03\testfile.dat 8 0x0 6000
A sample command line looks like this:
call sqlio -kR -s60 -fsequential -o8 -b64 -LS -Fparam.txt
My question is this:
When I test just 1 mount point I see 850MB/sec and 14k IOs/Sec, but when I test multiple files 850MB/sec is the most I ever see. So I believe I am hitting a bottleneck somewhere. The host has 8 4-gigabit fiber channel cards in it so I have a hard time believing it’s that, so I am stuck in “guessing” it’s the HBA/SP’s or SQLIO.
Is there something I am missing that could be the bottle neck? Is this normal behavior or should SQLIO be aggregating up the throughput across all mount points?
As a side note, in an attempt to prove that SQLIO was not the problem and that it wasn’t “averaging” the bandwidth across files, I ran 2 instances of SQLIO at the same time on different mount points and saw roughly 400mb/s on each. To me that proved that it’s not SQLIO.