This is how I tested the feature: Create couple of disks: qemu-img create -f qcow2 /var/lib/libvirt/images/test1.qcow2 1G qemu-img create -f qcow2 /var/lib/libvirt/images/test2.qcow2 -b /var/lib/libvirt/images/test1.qcow2 qemu-img create -f qcow2 /var/lib/libvirt/images/test3.qcow2 -b /var/lib/libvirt/images/test1.qcow2 Then adjust configuration of two domains: virsh # domblklist gentoo Target Source ------------------------------------------------ fda /var/lib/libvirt/images/fd.img vda /var/lib/libvirt/images/gentoo.qcow2 vdb /var/lib/libvirt/images/test1.qcow2 hdc /home/zippy/tmp/install-amd64-minimal-20150402.iso virsh # domblklist fedora Target Source ------------------------------------------------ sda /var/lib/libvirt/images/fedora.qcow2 sdb /var/lib/libvirt/images/test2.qcow2 hda - With this configuration, fedora and gentoo should not be able to run at the same time: virsh # start fedora Domain fedora started virsh # start gentoo error: Failed to start domain gentoo error: resource busy: Lockspace resource '/var/lib/libvirt/images/test1.qcow2' is locked Cool! But with slight change, gentoo should be able to run: virsh # domblklist gentoo Target Source ------------------------------------------------ fda /var/lib/libvirt/images/fd.img vda /var/lib/libvirt/images/gentoo.qcow2 vdb /var/lib/libvirt/images/test3.qcow2 hdc /home/zippy/tmp/install-amd64-minimal-20150402.iso virsh # start gentoo Domain gentoo started virsh # list Id Name State ---------------------------------------------------- 10 fedora running 11 gentoo running Awesome! Michal Privoznik (2): qemuProcessStart: Parse backingStore for all disks virDomainLockManagerAddImage: Recursively lock backing chain src/locking/domain_lock.c | 53 +++++++++++++++++++++++++++++------------------ src/qemu/qemu_domain.c | 11 +++------- src/qemu/qemu_process.c | 6 +++++- 3 files changed, 41 insertions(+), 29 deletions(-) -- 2.4.6 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list