Mount and migrate an Oracle backup for instant recovery to any target

Instant recovery of an Oracle database to any target using Backup and DRMount and Migrate is a two-phase operation: TheRestore Mount phase providesinstant access to the database by starting it from a backup/recovery appliancepresented backup image. TheMigration phase migrates the database datafiles to the production storage while the database is online.

How it works

Restore Mount Phase: provides instant access to the database from a selectedimage presented by the backup/recovery appliance.

  • A copy of the selected backup image is mapped to the target database serverand presented to the ASM or file system layer (based on the source databasebackup image format).
  • RMAN API is used to perform the following processes:
    • Restore the Control file and Redo Log file to the specified controlfile and redo file location (ASM diskgroup or file system).
    • Switch the database to the copy of the image presented by the backup/recovery appliance.
    • Roll-forward all available archive logs to the specified recovery point.
    • Open the database in read and write mode.
  • The database is running from the mapped copy of the backup imagepresented by the backup/recovery appliance.
  • The Control File and the Redo Log file of the database is on theselected local production storage (ASM diskgroup or file system) on thetarget.
  • After a successful restore mount operation, the database is available forproduction operation; a migration option is available to move the databack to the production storage (ASM disk group or file system) using theOracle online datafilemove API. The migration can take place while thedatabase and application is up and running.

Migration Phase: moves the database datafile online to the production storage.

  • Data migration runs in the background. The Oracle online datafile move APIis used to migrate the data.
  • Datafiles are moved from the Backup and DR presented copy of backupimage to the selected target database storage (ASM diskgroup or file system).
  • The Backup and DR presented copy of the backup image (ASM diskgroupor file system) is removed and unmapped from target upon completion of migration.

You can track the progress of the Restore Migrate job in the management consolemonitor.

Phases of the mount-and-migrate process

A mount-and-migrate process goes through two distinct phases, a restore-mountfollowed by the data migration.

Restore Mount phase

  1. From the Backup and DR Service management console, open theApp Manager>Applications list.
  2. Right-click the database and selectAccess.
  3. Select the latest snapshot to recover and chooseRestore.

  4. On the Restore page, chooseMOUNT AND MIGRATE.

    • Target: For all configurations, eligible Oracle database servers will beavailable to choose under the drop-down. Select the target server for restorefrom the drop-down.
    • Replace Original Application identity: This option is only available whena restore is performed to a new server on the same appliance where the backupwas originally generated.
      • Yes: This replaces the original application and will carry the sameapplication ID, jobhistory, backup images and backup plan as the originalOracle application.
      • No: This won't replace the original application. It will be discoveredas a new application as part of restore job.
    • Rollforward time: Choose a date and time for a database protected with logsto recover to the required point in time.

    • Application Options:

      • DATABASESID: This is pre-populated with the protected database SID nameand is immutable.
      • USERNAME: This is pre-populated with source database Oracle softwareowner. Update the USERNAME if the Oracle software owner on the selectedtarget server is different.
      • ORAHOME: This is pre-populated with source database Oracle Home path.Update the Oracle Home directory if the Oracle Home path is different onthe selected target server.
      • Advanced Options: This is pre-populated and displays all the databaseparameter settings (from pfile) at the source at backup time. Make sure theparameter value is correct for the target database server (source ornew target) for restore.

    • Mapping Options:

      • CONTROL FILE TARGET TYPE: Select the database control file target type(ASM diskgroup or file system) for the database from the drop-down list.FS target type is not supported for backup images in ASM format.

        Backup image formatSupported storage type
        ASMASM (FS not supported)
        FSFS, ASM

      • CONTROL FILE TARGET: A drop-down list shows the available target(ASM diskgroup or file system) based on selected CONTROL FILE TARGET TYPE.Select the target for the control file location from the list ofeligible disk groups or file systems in the drop-down list. Multipleselections can be made to multiplex the control file. This locationis also used as the destination for the temporary files for thetemp tablespace.

      • REDO TARGET: If none is selected then the Control File Target will beused for the Redo target. A drop-down list shows the available target(ASM diskgroup or file system) based on the selected Control File TargetType.Select the target for the redo file location from the list ofeligible disk groups or file systems in the drop-down list. Multipleselections can be made to multiplex the redo file.

      • RAC NODES: This is only available when the selected restore target is setup with a RAC cluster. Click+ to add the RAC node list for restoreto RAC cluster.

  5. Click thePre-Flight Check. If the pre-flight check fails, fix the issueand resubmit the pre-flight check.

  6. ClickSubmit to submit the restore job.

Note: When the job is complete, the database will be available for productionoperation. The database will be running out of the backup image copypresented by backup/recovery appliance where Control File,and the Redo Log file of the database will be on the selected local server.Note: Adding a new data file in the database after the restore mount operationand before starting the migration job: Post restore mount operation, thedatabase is running from the Backup and DR presented backup image. Toadd a new datafile, make sure to use thedefault db_create_file_dest locationwhich will create the data file on backup/recovery appliances presented disk.Adding the data file with location before migration to the local disk is startedwill lead to database backup failure.Note: Migration is blocked until the post-restore mount database backup iscomplete. The baseline backup for restore mounted database from a snapshot imageis instant, because it uses the backup/recovery appliance internal snapshot of thedata disk.The baseline backup of a restore mounted database from an OnVault pool may takea long time depending on the size of database, because the backup usesconventional RMAN.Note: Migration of a large database can take a long time. If you plan toupgrade the backup/recovery appliance, and if you have a restore mounteddatabase (an active mount), make sure that you either complete the migration,or cancel the restore mount to remove the restore mounted database.

Migration phase

  1. From the management console App ManagerApplications list, right-clickthe database and selectAccess.

  2. Select the mounted image. From the active mount selectMigrate.

  3. On theMigrate page, forCopy Thread Count, enter a thread countvalue to configure parallelism for the online datafile move operation.

  4. For Migrate Mapping, map the source volume to Target volume (ASM diskgroupor file system) in these scenarios:

    • Source volume displays source database data file distinct locations(ASM diskgroup or file system) name.
    • Required Size displays the space required on the target location(ASM diskgroup or file system).
    • Target volume displays all the eligible target locations(ASM diskgroup or file system) for datafiles. Select the appropriate targetfor source datafile to target datafile location mapping.

  5. Click the pre-flight check. If the pre-flight check fails, fix the issueand resubmit the pre-flight check.

  6. ClickSubmit to submit the restore job. When the migration job iscomplete, the Backup and DR presented backup image copy(ASM diskgroup or file system) will be removed and unmapped from the target,and the database will be running from your production storage.

Note: After a successful database migration, Oracle may occasionally hold lockson staging disks for an extended duration. If this occurs, analyze theprocess types holding the locks. If it is safe to do so, manually release thelocks by killing the process, or by restarting the database. When the locks arereleased, re-run the job to remove the staging disks. This should remove thedisks and mark the job as successful.

The Oracle DBA Guide

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Last updated 2026-02-19 UTC.