high latency in vm solved by live migrate, why?

Question

2019 Hyper-v clusters with iSCSI Netapp All-Flash storage system. We see that busy 2016 servers (sql during queries and fslogix during login times) have huge latency issues (3000ms). Tried and tested a lot of settings with suppliers but problem remains. Anyhow, we found that moving the affected vm to another host solves the problem instantly at least for that day. Apparently something gets reset but we don't know what and if that might be a clue to the root cause. Does anyone in the community have an idea why this is?

Thanks.

Answer 1

Hi. Thank you for your question and reaching out. I’d be more than happy to help you with your query

It sounds like you have done a lot of troubleshooting, but you haven't been able to identify the root cause of your latency issues. One possibility is that the iSCSI Netapp All-Flash storage system is having issues with the Hyper-V clusters. You may want to try to update the firmware on the system to see if that helps. Additionally, it is possible that the SQL and FSlogix servers are experiencing issues with their configurations or the way they are interacting with the storage system. You may want to try to make adjustments to their configurations to see if that helps. Finally, it may be helpful to review the system logs to see if there are any errors that could be related to your latency issues.

If the reply was helpful, please don’t forget to upvote or accept as answer, thank you.

Answer 2

Double post