If I understood correct, the libguestfs actually start a qemu vm under the hood. When I call guestunmount it unmounts the image then shutdown the vm. However, if I do this programmably, commonly it will fail due to the vm is still using the image: guestmount -d guest1 mnt # do something with the image guestunmount mnt virsh start guest1 I have to add sleep between guestunmount and other command. However, this time interval is not certain, it can be quite long at some time. So I propose to add some option to let the guestunmount only return after the qemu vm release the image. Is there any work around right now for this?