How to restore an SQL database using a log backup if the last database backup failed

Problem

Consider the following scenario:

1. Full backup of a database is completed successfully.
2. Log backup of the database is completed successfully.
3. Full backup of the database is failed due to a network failure.
4. Log backup of the database is completed successfully.

In this scenario, restoring #4 log backup results in a restore error.

Error Message

Completed status: Failed

Final error: 0xe0008492 - Database Query Failure. See the job log for details.

Final error category: Resource Errors

Restore- <server-name>\MSSQLSERVER V-79-65323-3117 - An error occurred on a query to database <database name>.

V-79-65323-3117 - The log or differential backup cannot be restored because no files are ready to roll forward.

Cause

Backup Exec attempts to automatically restore all backup sets in the backup chain even if one of the backup sets is corrupted.

In the scenario above, since the preceding full backup set is corrupted, the restore job fails.

For more information about the backup chain (or recovery chain), refer to:

Data Lifecycle Management (DLM) Backup Chain and Dependency Rules

 

Solution

This issue is fixed in Backup Exec 25

Workaround

To skip the corrupted database backup set and restore using the log backup, follow these steps:

1.    Select "To an individual backup set that I select from all available backup sets for this database" in the restore wizard. (Figure 1)

Figure 1.

2.    Hold down the control key and select the successful full backup set and all subsequent successful log backup sets. (Figure 2)

Figure 2.

3.    If there are incremental backups, select the following backup sets with the control key:

a) A successful Full backup set

b) Successful incremental backup sets since the successful full backup set

Do not select failed and corrupted incremental backup sets and subsequent incremental backup sets

c) All subsequent successful log backups since the last successful incremental backup.

4.    If there are differential backups, select the following backup sets with the control key:

a) A successful full backup set

b) The last and successful differential backup set after the Full backup set and before the failed and corrupted backup sets

Do not select a failed and corrupted differential backup set and subsequent differential backup sets

c) All successful log backup sets since the last differential backup set

5.    Click next and continue the restore operation.