When your disk image is stored on a ZFS volume or on a ZFS file, you can create snapshots of this disk image by using the ZFS snapshot command.
Before you create a snapshot of the disk image, ensure that the disk is not currently in use in the guest domain to ensure that data currently stored on the disk image are coherent. There are several ways to ensure that a disk is not in use in a guest domain. You can either:
Stop and unbind the guest domain. This is the safest solution, and this is the only solution available if you want to create a snapshot of a disk image used as the boot disk of a guest domain.
Alternatively, you can unmount any slices of the disk you want to snapshot used in the guest domain, and ensure that no slice is in use the guest domain.
In this example, because of the ZFS layout, the command to create a snapshot of the disk image is the same whether the disk image is stored on a ZFS volume or on a ZFS file.