Restoring Clean Logs onto the Shadow Database

This procedure enables all clean logs created since the last database backup, except for the current clean log, to be restored on the new Shadow Database, so as to bring it up-to-date with the live database.

Note

  • This procedure must be carried out on the live database.
  • This procedure should be executed after the Shadow Database has been re-made using option 2 on the Database Recovery menu.

Procedure

  1. Select option 3 on the Database Recovery menu. A message is then displayed describing the purpose of the procedure ? enter y  to continue.

  2. The procedure to start restoring clean logs is initiated with the message:

    Locating next Clean Log to restore

    indicating that it is looking on the Shadow Database to determine the last clean log to be restored.

    Note

    After certain types of system or disk failures, tlmenu may fail to find the name of a previous clean log that has been restored on the Shadow Database. It then displays the messages:

    Warning: Database has no current Clean Log
Enter name of the first Clean Log to restore :

    Caution

    If you enter the wrong clean log name, the database will be corrupted.

    Determine the name of the first clean log used on the live database since the last backup was carried out, and enter it here.

    Clean log names are case sensitive. For example, CLOG  must be entered as upper-case.

    Having determined the name of the next clean log to be restored, tlmenu checks to see if it exists on disk.

  3. If the clean log is present on the system, tlmenu asks:

    Do you want to tlrestore clog_name (y/n/q) ? :

    Enter y  to restore the specified clean log onto the Shadow Database. Continue with step 8.

  4. If the next clean log does not exist on disk, tlmenu asks:

    Clean Log clog_name does not exist on disk, or is incomplete on disk.
    Do you want to restore Clean Log clog_name from tape (y/n/q) ? :

    Enter y  to load the clean log from tape onto the Shadow Database.

  5. You are then prompted you for the tape device to attach to the Shadow Database, as follows:

    Enter SHADOW tape unit :

    Enter the device number.

  6. tlmenu then pauses to ensure that the clean log tape is mounted and ready to be loaded, displaying the prompt:

    Is correct tape mounted on SHADOW tape unit n (y/n/q) ? :

    Ensure that the correct tape is mounted and enter y  to load the clean log from tape.

  7. Once this is completed you are then prompted to start the restore with:

    Do you want to tlrestore clog_name (y/n/q) ? :

    Enter y  to restore the specified clean log onto the Shadow Database.

  8. On completing the restore, tlmenu looks for the next clean log in sequence. If it finds one, it re-prompts you either to restore it from disk onto the Shadow Database or to reload it from tape first (step 2).

    Steps 2 to 7 are repeated until the next clean log is the active clean log on the live database.

  9. Finally the Shadow Database daemon is killed and the Shadow partition is disabled. The procedure ends with the messages:

    Restore of Clean Logs onto shadow database complete
Now secure shadow database with a Save
  10. Now use option 8 on the Routine Maintenance Menu to save the Shadow Database, as described in the procedure Saving the Shadow Database.