For Linux clients, a bare metal boot CD and master backups are used for disaster recovery. See Bare Metal for Linux for details.
Note: For VMware clients running Linux, the VM must be configured to use the E1000 network adapter and its SCSI controller must use LSI parallel logic. Bare metal restore is not supported on Linux VMs using the VMXNET 3 adapter or whose SCSI controller uses VMware paravirtual.