FailSafe Database Recovery

This topic describes procedures carried out from tlmenu’s Database Recovery menu to recover a FailSafe database after a system/application failure. The procedures are:

• Checking/reconfiguring databases prior to recovery.
• Rebuilding and restoring the Secondary Database.
• Restoring all Clean Logs apart from the active log onto the Secondary Database.
• Resynchronising Databases for FailSafe Operation.

Overview

Recovery of a database in a FailSafe configuration, after a system or application has failed, is carried out from the the tlmenu Database Recovery menu, displayed by selecting option 3 on the main Administration menu.

Recovery is carried out in four stages:

1. Reconfiguration of the current standby secondary database as a standalone primary and enabling of users to logon while the failed primary is being repaired.
2. Remaking of the failed database. If the database is not enabled for Rapid Recovery, this means restoring the last backup from tape and reapplying clean log updates. If the database is enabled for Rapid Recovery, this means executing the realrecover command to run the Rapid Recovery process.
3. Restoration of all clean logs made since the last backup (if the database is not enabled for Rapid Recovery), or since the system failure (if the database is enabled for Rapid Recovery), onto the restored secondary, except active log.
4. Resynchronisation of new primary and secondary databases to re-establish FailSafe operation.

Each procedure, started by selecting a sub-menu option, comprises a sequence of message prompts to guide you through the process. Refer to Replies to Prompts for a description of the required responses.

Transaction Logging Menu System             Mon Jul 31 1999
Database name : dbase2                      Host name : crime
State         : FailSafe enabled, secondary, inactive


     Database Recovery
     =================

     1. Check/Reconfigure Databases Prior to Recovery (secondary only)
     1. Check Configuration of Remote Database (primary only)
     2. Rebuild and Restore the Secondary Database
     3. Restore Clean Log(s) onto the Secondary Database
     4. Resynchronise Databases for Failsafe Operation


        Enter option (1-4) : _

FailSafe Database Recovery Menu