14 Oct 2012 » Adding a Physical Disk to a Guest with Libvirt / KVM
It can’t be done with virt-manager. That one took me a while to figure out. As far as I can tell, virt-manager works with storage pools. You can make a disk into a storage pool, but you can’t add an existing disk directly to a VM.
Luckily the fix is easy: you add the disk to the domain’s xml config file by hand. So open up
/etc/libvirt/qemu/<your-vm>.xml in your favourite editor and add a
<disk> section to the
<disk type='block' device='disk'> <driver name='qemu' type='raw'/> <source dev='/dev/md/storage'/> <target dev='vdb' bus='virtio'/> </disk>
This will make the host’s
/dev/md/storage available in the guest as
/dev/vdb. After changing a domain’s config by hand, you have to reload the config by hand. Log in to your host and issue this command:
# virsh define /etc/libvirt/qemu/jetsetetser.xml Domain jetser defined from /etc/libvirt/qemu/jetsetetser.xml
Here is a nice resource with more information about managing vms with libvirt.