Database-Only Restore

Database-Only Restore

This scenario assumes the following starting point:

• The system where the restore is being performed is the system that generated the backup and the databases are to be restored to their original location.

• You have identified the set of databases that require restoration.

• InterSystems IRIS may be up and users may be accessing other databases normally; the databases requiring restoration may not be required for startup.

• InterSystems IRIS may be unable to start fully; the databases requiring restoration may be required for startup, or damaged in a way that is preventing startup from completing.

To perform a database-only restore:

1. If the database is not started already, start it as described in Starting InterSystems IRIS for Maintenance. Starting the database ensures that any pending automatic recovery to existing databases occurs immediately and does not conflict with the databases that you are about to restore on subsequent startup.

   If the system is already started and you are restoring databases that users may attempt to access during the restore process, InterSystems recommends that you shut down and restart as described in Starting InterSystems IRIS for Maintenance.

   The following table describes recommended procedures to resolve the problems that prevent a successful start of the database.

   Problem	Solution
   1. InterSystems IRIS fails to start	Starting InterSystems IRIS in maintenance mode allows the system to start even if a database that is required for startup cannot be mounted. However, if there is automatic journal recovery pending for a database that is marked as required for startup, the database does not skip it. Therefore, if damaged databases are still preventing the system from starting: Rename the IRIS.DAT files to make the database completely inaccessible. Change the configuration to mark those databases as not required for startup, Try again to start the system as described in Starting InterSystems IRIS for Maintenance.
   2. If InterSystems IRIS cannot start due to a damaged IRISSYS database	Temporarily replace the IRISSYS database with a copy from an External Backup, or from a new install of the same version of InterSystems IRIS. This is temporary solution to get the system started to complete the restore procedure.
   3. InterSystems IRIS still does not start	You may need to restore all databases following the procedure in Full System Restore. For additional help, contact InterSystems Worldwide Response Center (WRC)Opens in a new tab.

2. Depending on the strategy you used to back up the database, restore each database as follows:

   Backup Strategy Used	Database Restoration Sub-procedure
   External Backup or Cold Backup	For all databases except IRISSYS: Dismount the database from InterSystems IRIS. Copy the IRIS.DAT files from the backup media to their original locations. Remount the database. If you are restoring the IRISSYS database, restore it to an alternate directory temporarily.
   Online Backup	Follow the instructions in theOnline Backup Restore Utility to: Restore the last full backup. If you have done cumulative backups since the full backup, restore the last one; otherwise, continue with the next step. Restore all incremental backups done since the last cumulative backup (if there is one), or the last full backup (if there is no cumulative), in the order in which the backups were run.
   concurrent external backup	Perform the same steps as documented for External Backup (in this table) to restore the “dirty” copy of the IRIS.DAT files, then apply the incremental backup as documented for Online Backup (in this table).

3. Follow the instructions in Journal Restore Following Backup Restore.

4. If you started InterSystems IRIS as described in Starting InterSystems IRIS for Maintenance, and you are ready to allow users on the system, stop and restart InterSystems IRIS normally. You can perform application validation or additional maintenance before restarting.

   Note:

   If you restored the IRISSYS database from External Backup or Cold Backup to a temporary alternate directory as described in the table in step 2 of this procedure, you must replace the existing IRISSYS database with the IRIS.DAT file from the temporary directory after shutting down (before restarting) InterSystems IRIS.