21:51 < foxx> hello! does anyone know if libguestfs supports any sort of COW (copy on write) functionality? for example, if i mount an image which is RO, can i make it write any changes out to a higher dir (such as how overlayfs/aufs works) The answer is yes. Create a qcow2 overlay on top of your image before starting: qemu-img create -b original.img -f qcow2 overlay.qcow2 guestfish -a overlay.qcow2 [etc] Changes are written to overlay.qcow2. The original is not modified. You can also display differences between the overlay and the original using 'virt-diff': http://libguestfs.org/virt-diff.1.html https://rwmj.wordpress.com/2013/12/19/new-in-virt-tools-virt-diff/#content Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 100 libraries supported. http://fedoraproject.org/wiki/MinGW