Refer to the following list for information and tips about Enterprise Vault agent backups:
When you attempt to back up an SQL database, Symantec recommends that you perform a full backup before any incremental backup. If you perform scheduled incremental backups when no full backup exists the following occurs:
The first scheduled Cumulative incremental backup is a streamed-base backup and is treated as a full backup . However, the Backup, Archive, and Restore user interface displays the backup as a Cumulative backup. Any following scheduled Cumulative incremental backups are "cumulative" in nature.
The first scheduled Differential incremental backup is a streamed-base backup and is treated as a full backup . However, the Backup, Archive, and Restore user interface displays the backup as a Differential backup. Any following scheduled Differential incremental backups are "differential" in nature.
If a full backup for an Enterprise Vault SQL database fails, manually initiate a second full backup and ensure that it finishes successfully before a Cumulative Incremental schedule backup starts.
If a full backup for an Enterprise Vault SQL database fails, any Cumulative incremental backups that were run after the failure and before the next, successful full backup cannot be restored. This issue only affects Cumulative backups after a failed full backup . Differential incremental backups are not affected, even after a failed full backup .
An attempt to restore these Cumulative Incremental backup images fails with a status 5 error, and this failure can result in a data loss. The tar log file contains the following message:
SQL Error Description: This differential backup cannot be restored because the database has not been restored to the correct earlier state.
You can however, restore the data from the Differential backup images. You must restore all of the Differential backup images after the restore of the last full-backup image.
To avoid this issue, Symantec recommends that you make sure the full backup is successful before you begin a Cumulative incremental backup. Ensuring a successful full backup before you attempt Cumulative backup guards against a data loss scenario.