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. […]
The code snippet in this blog post is an example of how to add iSCSI targets to an ESXi iSCSI initiator. But there is also a loop within processing a host, that sets iSCSI target parameter. For example this can be used when a storage vendor recommends to disable delayed acknowledgment per iSCSI target, like HPE does for 3PAR and LeftHand. Here you can see […]
FC AFA (all flash array) 3PAR systems show quite a good latency on reads and writes. When operating an iSCSI AFA 3PAR it could happen that the systems show a rather high write latency on ESXi hosts. In this post you can read how to fix this.