Qubes 4.1 strange low performance

Hello,

When I’m using high number (15-20~) of VMs simultaneously, dom0 becomes sluggish - for example, you notice some lags when your mouse is moving through your list of VMs. Overall, OS becomes slower, inside VMs too.

What is strange:

  1. dom0 CPU load is 20% at the same moment, 4000 MB RAM
  2. Most VMs CPU load is 0% and like 2-3 of them are at 50-80% CPU load when lags happen
  3. System RAM is 64 GB, all VMs combined are using about 40~ GB of RAM at the same time
  4. I don’t remember encountering this issue in Qubes 4.0

According to these parameters, there is no way that my Qubes setup is overloaded, but…I have poor system performance anyway.

Any ideas how to solve this issue? Help is greatly appreciated!