I have a filesystem on a RAID1 partition created with a 'missing' mirror so I can periodically sync with an external drive for backup. Now I'd like to move the contents to a different machine that has a matching partition with minimal downtime. Is it possible to export the new partition via iscsi or an nbd device so that the old system will sync to it over the network allowing an unmount of the old to be followed by an immediate mount of the new mirror with a very short time when it will be unavailable?