Restoring Data From Backup Sets

In order to access the data hot copied into backup sets, it must be restored into a database archive.

An Incremental Hot Copy is a Hot Copy with atoms omitted. Additionally, the atoms have not been modified since written to the previous backup elements.

Note: Before an Incremental Hot Copy operation can be performed, a new full Hot Copy backup using a Backup Set must be completed. Existing 3.0-x Hot Copy Archives (without a Backup Set) cannot be used as a reference for an Incremental Hot Copy.

The result of the Full Hot Copy operation is a new Backup Set directory from which Incremental and Journal Hot Copy operations can store the data.

The control folder located in the Backup Set directory must be accessible by the Hot Copy command to perform an Incremental or Journal backup. The entire full backup image does not need to be accessible by Hot Copy command for the Incremental Hot Copy command to be executed.

Only one backup can run at a time. Hence, users cannot execute an Incremental backup command while a Full or another Incremental Hot Copy is being executed.

As part of the Hot Copy command, users must manually specify the Storage Manager(s) to be backed up.

While not enforced, it is recommended that Incremental backups be made against the same Storage Managers used for the Full backup.

To learn more about Backup Sets and Journals, read: Backup Using Backup Sets

Restoring the data

When using Incremental backups, you can restore to a specific transaction using timestamps and following these step:

1. Identify the Backup Set folder - choose this folder when invoking the Hot Copy command

2. Find Available transactions using the nuochk command, as in the following example:

nuochk --report-timestamps --start-time "2017-12-10T00:00" --end-time "2017-12-10T23:59" 
/var/opt/nuodb/production-archives/BackupSets/12-10-2017 --format simple

3. The output of the --report-timestamps looks like the following code: - the left column has the timestamps and the right column shows the transaction ids:

2017-12-10T19:12:37 3970
2017-12-10T19:12:45 4738

4. Restore a new copy for backup and journaling from the backup set by invoking the id. In this example we will restore to the timestamp of 2017-12-10T19:12:37

nuochk --restore-snapshot 3458 --restore-dir /var/opt/nuodb/production-archives/testrestore

5. Start a new SM from the restored directory:

start process sm database testrestore host localhost archive /var/opt/nuodb/production-archives/testrest 
initialize false options

6. Start new TE to integrate with the SM:

start process te database testrestorehost localhost options '--dba-user dba --dba-password dba'

7. The nuochk restore operation is an offline operation. Do not restore to the transaction on a running database. Neither the source nor the target archives can be in use by a running database. The nuochk restore operation creates a new archive and you can then specify this archive when starting an SM or SSM.

For more information, see NuoDB Check.