Historical OpenVMS V6.2 service guidance uses BACKUP/IMAGE/NOALIAS when creating a system-disk save set so that the VMS$COMMON directory tree is copied rather than relying on the source alias. This exact alias case has not been revalidated for Avanti 5.1.0. Confirm the qualifiers in the BACKUP documentation for the installed release and test both the save and restore on a disposable target before relying on the result.
The following device names are examples only. Substitute the actual source, save-set, and disposable restore devices; review the effect of /IGNORE=INTERLOCK before using it on an active system.
Image Backup Command
$ BACKUP/IMAGE/NOALIAS/IGNORE=INTERLOCK DKA0: MKA600:SYSTEM.BCK/SAVE
Image Restore Command
$ BACKUP/IMAGE MKA600:SYSTEM.BCK/SAVE DKB0:
After the restore, verify the VMS$COMMON alias and contents, boot the restored copy independently, and retain the original system disk until recovery has been demonstrated.