Dual-use guest for LXC and KVM?

Question

Would it be possible to install (and maintain by simple means, such as apt-get dist-upgrade) a "dual-use" setup? I.e. install an guest instance in a way which allows me to run it either as LXC or as KVM guest and switch between the method at will?

Concerning the apt-get dist-upgrade mentioning above, I mean that I want to install it in a way so that the kernel and GRUB are updated in the guest for when it runs fully virtualized in KVM - given this is at all possible.

Answer 1

Yes you can. Upgrading would not be a problem, you would use apt-get. It would almost certainly be best to update when running the guest in KVM.

To use is for LXC, you would mount the disk, and specify the mount location in the LXC configuration.

To do this, use libguestfs

apt-get install libguestfs-tools

http://packages.ubuntu.com/quantal/libguestfs-tools

You would then mount it with guestmount

Just be sure NOT to mount a running KVM guest (well you could mount it RO).

guestmount -a your_kvm.img /mount_point

See also

http://ebalaskas.gr/wiki/kvm/libguestfs

http://libguestfs.org/guestmount.1.html