I know this is an old thread but this topic came up at one of my customers.
Just in case somebody is looking for our definite answer, please have a look at KB124.
Nimble Storage arrays support a fully functional TCP congestion control algorithm, so VMware KB 1002598 does not apply to Nimble arrays and we don't recommend disabling TCP delayed ACK.
Further more, sometimes disabling TCP delayed ACKs can mask the real cause of a slow network.
We just had a purple screen of death on a new dell server running ESX 5.5 they collected the dumps and sent us some items to update. One of the items was
iSCSI Storage - Nimble
Recommend disabling DelayedACK - https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1002598
# Set DelayedACK -- LoginTimeout -- LunQDepth SOFTWARE iSCSI - (REQUIRES REBOOT)
I haven't done this on any of my ESX server connected to my nimble storage.
Is this needed?