qemu

Recently, we wanted to start a Virtual Machine running a Windows installation from a physical hard disk.

We could not find a way for GNOME Boxes to achieve this, so we installed qemu to do so.

We installed qemu using:

sudo dnf install qemu -y;

Configuring our command to start the Virtual Machine from the physical hard drive:

• Our hard disk was identified on the physical machine as /dev/sda so we set the -hda parameter to that value.
• Then we added the parameter -boot c to instruct the virtual machine to boot from the first hard disk.
• The default guest start-up RAM size was 128 MiB, so we set the parameter -m to 4096 to give to the virtual machine 4GB of RAM.
• Finally we added the -snapshot parameter which instructed the system to write to temporary files instead of the disk image files (all disk images are considered as read only).
  In this case, the raw disk image used are not written back. When sectors are written, they are written in a temporary file created in /tmp.
  You can however force the write back to the raw disk images by using the commit monitor command (or C-a s in the serial console).

In the end our command was as follows:

sudo qemu-kvm -snapshot -m 4096 -boot c -hda /dev/sda;