I was really surprised by few Parallels activities I did this week that made my 2017 MBP (2.6ghz quad core i7, 16gigs RAM) unusable while running. Windows 10 Pro VM had grown to 100gigs in size. I deleted a very old snapshot from the VM. Took more than an hour to complete Reclaimed space (it said 12 gigs) from the Win 10 VM mentioned above. This also ran for more than an hour and my MBP was completely unusable during this time. Screen was black, no response from mouse/trackpad, touchbar was black. Really looked like the machine was hung, but I just let it run. Win 10 VM downloaded a cumulative 1903 update. I rebooted the VM when prompted to Restart. MBP again got super sluggish, mouse was unusable, other native Mac apps showed beach balling when attempting to switch to them. Took about 20 min to recover to a usable state. In each case, as soon as Parallels was finished what it was doing the MBP returned to its normal speedy self. Why is Parallels app able to completely overwhelm the CPU and make the rest of the machine unusable when performing these kinds of tasks? Is there a way to throttle the app so it doesn't consume all available resources?
