There are many ways, many programs, and many processes that you could step through. Figure out what VM software you will use under Linux to pick your virtual disk file format, the sort when you are going to backup your existing install, and if anything is in your way like disk encryption.

If you can boot a live linux or pull the drive, look at qemu-img, I haven’t used it myself in awhile for syntax but Google suggests a command like this will work for you

sudo qemu-img convert -f raw -O qcow2 -p /dev/sdX /path/to/disk.qcow2

I don’t remember why but years ago I opted for Moode over Volumino. Just upgraded from a pi2 running Moode 8 to a pi3 on Moode 10. At some point they upgraded to a 64bit base os forcing my hardware update.

Local library from a Nas, Streaming sources , mpd controls , connects with many platforms, started using it with Home Assistant music server last summer running my outdoor speakers.

I don’t have hands on experience with this, but I can say that once you move into addon cards the chance for hotswap from drive bays goes up. Hotplug is a feature that many of the on board and lesser data chips don’t support well.