Facility for using images created by backup software to recreate an entire machine as it was at the point in time in the past when the backup was taken. The facility can be extended so as to bring up a set of machines which together serve some logical business function as in a cluster or federated servers, and further extended so that an entire data center may be virtualized from backup images. The virtualized servers provided may serve as an alternate data center standing in case of disaster or to meet maintenance windows achieving low cost Instant Disaster Recovery. A set of virtual machines may stand in for physical machines for a period of time and then resynchronized or re-seeded to physical machines via a combination of bare metal recovery and re-synchronizing from live LXJNs that form the virtual machine disks.