I'm using the newest vCenter and ESXi 7.0.2.
There is only one VM become unresponsive (so far 2 times) when it was started to create a snapshot. In the meantime, the task of "Create virtual machine snapshot" status under "Recent Tasks" was at 0% without any progress. I need to wait for 30 minutes until that task had its status changed to "Operation timed out" then the VM resumed.
What I mentioned above are what I've seen in "Tasks and Events", it only shows me what was going on without the cause, which I desperately need to know. Is there any way I can find the in-depth reason of the problem?