I have performance issues on my infrastructure. I have connected array Dell Equallogic 6100 via SAN (1Gb/s) to my ESXi server. EQL is filled with SATA 7200rpm HDDs.
I created new lun with one test machine. When I tried IOPS benchmark on this machine, I got 300 IOPS for read and 1400 IOPS for write.These values are stable for every test.
When I tried the same test on pyhsical server connected to the same EQL, I got 750 IOPS for read and 1600 IOPS for write.
I made theese tests when the array is without load (20-30 IOPS per hole array).
I tested for 512bytes block. If I switch benchmark to 4K, I got only 200 IOPS for read.
I tried MPIO pathing fixed, Round Robin (set limit 1 IOPS instead of default 1000), thin or thick VMDK drive, but everything were the same. I also checked the switch ports configuration, which were made regarding to best practise.
Latency from ESXi to EQL is very low.
When I looked to the SAN HQ, I got same numbers like in benchmark test.
My question is, why the vritual machine has so low read IOPS performance?