Hello
I wanted to compare performance of VMFS Datastore vs RDM .I used IOMETER IOPS and latency measuring in EMC Unity 300 , I created one pool that include 8 SSD with 100 GB LUN
i test the performance of lun with 2 situation ,in 1st test I created VMFS Datastore that present to a VM and test that with IOMETER after that in 2nd test i present LUN to vm with RDM the result was very different.
the specification of IOMETER include :
block size : 64kbyte
write/read : 30/70
random / sequential : 100/0
I extracted these result for VMFS:
total IO : 500
latency: 3 ms
I extracted these result for RDM:
total IO: 2000
latency: 0.3 ms
why the values very different?