I installed Ubuntu 21.10 and Fedora Kinoite as virtual operating systems inside Boxes. I allocated 8 GB RAM and plenty of space on my SSD, but both operating systems are so slow, they are unusable. They are barely responsive to things like clicking a window closed or selecting a preference. It was very easy to install the OS’s but it doesn’t do much good if they are essentially useless once installed. Anyone else having the same experience?
Maybe it’s a good start to check your BIOS setting if there any option to enable VM feature on your CPU first.
Also check if you have the no copy on write attribute set on the images directory and files.
Supposing you are on Btrfs, and that you are using the GNOME Boxes Flatpak
lsattr ~/.var/app/org.gnome.Boxes/data/gnome-boxes/* should show the