Hi Subhajit
Very kind of you to respond. The issue is this - I don't know if I have a performance issue - the MSA is not in production yet and I'm simply stress testing it myself.
However you have seen my other postings about extending the size of a pool (and extending a volume) and the problems it is causing me. You and a colleague kindly pointed out that the MSA2040 firmware is not supported with VMWARE 6.7.
I'm following this up with my vendor and vmware (very very slow).
If they do not get back to me in 24 hours I'll downgrade to ESXi 6.5 (which is supported) and run all my tests again (extending a Pool, extending a volume and performance).
ta,
p.s. Please note my MSA 2040 was purchased with only 10 disks (6 SAS 4 SSD)- so it will be extended in the future - no doubt.