Restoring System Tables with disk reinit and disk refit

When you are restoring the master database from a dump that does not reflect the most recent disk init or create database and alter database commands, restore the proper information in the sysusages, sysdatabases, and sysdevices tables.

• Restoring sysdevices with disk reinit
  If you have added any database devices since the last dump—that is, if you have issued a disk init command—you must add each new device to sysdevices with disk reinit.
• Restoring sysusages and sysdatabase with disk refit
  If you have added database devices, or created or altered databases since the last database dump, use disk refit to rebuild the sysusages and sysdatabases tables.