Running the old OS as a VM

I use the following scritp to run the "virtual" old OS:

#!/bin/bash

qemu-kvm -cpu kvm64 -m 1024 -k it -usbdevice tablet virtual-poldon-0001.qcow2

The script is very raw and it was easy to make an equivalent configuration under libvirt.

Mounting the images is a little trickyer as I used LVM on the old installation, so we have to:

1. connect a virtual block device to the qcow2 disk
2. scan the volume groups
3. mount them

This is done by the following script:

#!/bin/bash

modprobe nbd max_part=63

qemu-nbd -c /dev/nbd0 /media/SAMSUNG-Tera/poldon/writable-poldon-0001.qcow2 

vgscan

vgchange -ay

mkdir /media/poldon

mkdir /media/poldon_btrfs

mount -o rw /dev/vg_poldon/lv_root  /media/poldon

mount -o rw /dev/vg_poldon/lv_btrfs /media/poldon_btrfs

Umounting is done with this:

#!/bin/bash

umount /media/poldon 

umount /media/poldon_btrfs

rmdir /media/poldon 

rmdir /media/poldon_btrfs

sync

qemu-nbd -d /dev/nbd0 

killall qemu-nbd

sleep 5

killall -9 qemu-nbd