- `attach_snapshot` (string) - Default to `null/empty`. The name of an **existing** snapshot to which the builder shall attach the VM before starting it. If no snapshot is specified the builder will simply start the VM from it's current state i.e. snapshot. - `target_snapshot` (string) - Default to `null/empty`. The name of the snapshot which shall be created after all provisioners has been run by the builder. If no target snapshot is specified and `keep_registered` is set to `false` the builder will revert to the snapshot to which the VM was attached before the builder has been executed, which will revert all changes applied by the provisioners. This is handy if only an export shall be created and no further snapshot is required. - `force_delete_snapshot` (bool) - Defaults to `false`. If set to `true`, overwrite an existing `target_snapshot`. Otherwise the builder will yield an error if the specified target snapshot already exists. - `keep_registered` (bool) - Set this to `true` if you would like to keep the VM attached to the snapshot specified by `attach_snapshot`. Otherwise the builder will reset the VM to the snapshot to which the VM was attached before the builder started. Defaults to `false`. - `skip_export` (bool) - Defaults to `false`. When enabled, Packer will not export the VM. Useful if the builder should be applied again on the created target snapshot.