Install Debian11 Bullseye via virt on Ubuntu

Why virt

Recently I am working on packaging rasdaemon for Debian11 Bullseye. My package work is now works properly running on Ubuntu, and it's time for me to test it on Debian. However, I don't have a Debian machine, so I try to think about the possible solutions:

Steps

Some Misc Tips

If you need grant the normal user with sudo permission, login as root by su - root and then usermod -aG sudo <the account of normal user>. - is important for root to find out the command usermod.

Reference

Debian Wiki