I needed a test VM at work the other day so I just went with Debian because why not, during the install I chose KDE plasma as the DE. I did nothing else with it after installing it and after leaving it alone for a while (somewhere between 20-60 minutes) the CPU useage shot up to the point vSphere sent out an alert and the VM was unresponsive (the web console just showed a blank console which I couldn’t type in) It did this every time I booted the VM.
It seems to be the combination of vSphere Debian and KDE that causes this as I installed GNOME on the same VM and it was fine. I also created another Debian VM this time choosing GNOME during the install and that was also fine, until I installed KDE on that and then it started doing the same thing. I also created an Arch VM with KDE and that didn’t have any issues.
Any idea why this combination causes issues? Journalctl output of the last boot from both Debian VMs below:
Original VM: https://text.is/032Z Secondary test VM: https://text.is/JR45
Seconding the RAM issue possibility. If you can, shut down the host and run a memory test over a few days to see if it trips. Memory tests can take days to trip in some circumstances, in others, it’s immediate.