Recently we had to troubleshoot rather high storage latency at a customer site. The environment consists of Hyper-V hosts connecting to 3PAR arrays via iSCSI. 3PAR arrays are all-flash arrays (AFA). I know such problems in vSphere environments too. There higher storage latency can be caused by delayed acknowledgement (DelAck). Read more about this issue and how to configure DelAck on vSphere ESXi hosts here. […]