Catalina 10.15.4 slow boot, unresponsive, not responding, rainbow wheel, freeze

I start up my iMac today and it took forever to boot. When it does the finder isn't responding. Any click will trigger the wheel and the system freeze. Activity Monitor, Console and any application I attempt to run freeze. Parallels isn't even running.

 

First do a diagnostic test on the Mac (hold down 'D' at boot).
Then once this is passed reboot, and do a disk check. Hold Shift during boot. It'll then check your disk (will take a while).
Summat is amiss...

 

Yes, already did that multiple time. Volumes checked and "repaired" with disk utilities. I was able to open activity monitor and nothing looks out of the normal, cpu usage, memory are ok. I'm gonna try reinstalling Catalina.

 

Catalina, seems to be doing this on some 'non virtual' machines as well.
This site lists some things to try:
<https://macpaw.com/how-to/speed-up-macos-catalina>
I see you have already done the one about checking activity monitor.
Others are reporting similar problems under other virtualisation software.
How much RAM are you allocating to the VM?. Catalina is much bulkier than the older Mac OS's, and if the RAM amount is too small it could be perpetually swapping.
What does the activity monitor show for swap usage?.

 

thanks for the information.