Use KVM to boot a HarddriveJuly 25, 2020, 9:08 am
Have an old Harddrive recovered from a broken down maschine? Or do You want to install a operating system on a USBStick? You may consider using kvm for that.
I start by finding the device file, of the requireed drives.
lsblk -o NAME,SIZE,TYPE,MOUNTPOINT,UUID
Make sure to use the top level device (ex. /dev/sda), not a partition (ex. /dev/sda1)
Dont use Partitions, you have mounted. It might break the filesystem. If you dont use readyonly or copy on write options.
If you havent done it allready, you need to isntall kvm
sudo apt install kvmtool
Now to the hard part, using kvm. I usually hack myself a kvm command together, but for a more convenient way, you should consider using virtmanager.
kvm -hda /dev/sda -m 8G -cpu host -smp 4 -k de -vga qxl
This is one of the most simplest commands. The manpage is located here:
This sets, the primary drive, you need to change this to the drive you found earlier.
Alternatively you could use
I think one of the most interesting drive arguments is
read-only to boot potentially corrupted filesystems.
This simply sets the allowed memory size to 8GB.
This sets the cpu information.
kvm -cpu help to get a list of all supported types.
-cpu host tries to add all host-cpu features to the virtual cpu
This sets the cpu core count. I usually just put a number there, but you could go full creative with this one.
This just sets the Keyboard layout to German.
This sets the vga mode. check the man page for a list, of supported modes.
Booting a iso image
You have downloaded a few new linux distros and want to quickly check them out, without setting up a extra vm for every distro.
Its possible to simply boot the image.
-cdrom /home/user/Downloads/linuxmint20.iso -boot menu
You still can mount a hard drive, maybe a common home-partition? But be careful with partitions, that are already mounted. use them in readonly mode!