I am experiencing an issue where the disk latency is > 10,000ms for any guest VM hosted on node 1. Guest VM's hosted on node 2 have an average disk latency <500ms and I don't know why node 1 performs significantly worse than node 2. Moving / migrating a VM from node 1 to node 2 reflects an improvement in storage performance (and usability as a side effect). As a result almost all VM's are currently being hosted on node 2 rather than node 1 in a 50/50 split.
Host 1 & 2 are configured identically and are directly connected to each other (no switches) over 25G fiber SFPs. The storage is parsed directly though to CVM. Moving the VHD of the VM from one CSV to another does not make a difference. I have re-validated all configuration steps and cannot find a difference between the two host nodes and I am beginning to think that it may be an issue with how Windows is accessing the iSCSI resources offered by the CVM's.
What are some troubleshooting steps that I could look at next to investigate the performance issue? I will also note that the Windows event log shows high I/O latency events as well for the CSV's.
Host 1 & 2 are configured identically and are directly connected to each other (no switches) over 25G fiber SFPs. The storage is parsed directly though to CVM. Moving the VHD of the VM from one CSV to another does not make a difference. I have re-validated all configuration steps and cannot find a difference between the two host nodes and I am beginning to think that it may be an issue with how Windows is accessing the iSCSI resources offered by the CVM's.
What are some troubleshooting steps that I could look at next to investigate the performance issue? I will also note that the Windows event log shows high I/O latency events as well for the CSV's.
Statistics: Posted by andrew.kns — Mon Jan 13, 2025 5:02 pm