Automatic retry of unsuccessful backups

NetBackup for SQL Server provides the following options to retry unsuccessful backup attempts.

Automatic retry

NetBackup for SQL Server keeps track of the unsuccessful backups that may have resulted from the execution of a batch file. When the initial backup attempt is complete, the agent rewrites the batch file, including only those operations that failed. The rewritten batch file is launched automatically.

Manual retry

A manual retry is similar to an automatic retry except that NetBackup does not launch the rewritten batch file. Instead it is written to the install_path\dbext\mssql\retry\ directory. The user can then choose when to run the new batch file.

To use automatic retry, add the following line to your batch file.

RESTARTTYPE AUTO

By default, the unsuccessful backups are retried one time automatically after 60 seconds. To change the delay following the unsuccessful attempt, then add the following to your batch file.

RESTARTWAITSECONDS <integer>

You can also specify the number of retries. Add the following to your batch file.

NUMRESTARTS <1 to 9>.

To use manual retry, add the following line to your batch file.

RESTARTTYPE MANUAL

Retry may also be used with file checkpoints. You can create the batch file so that any parts of the operation that fail are written to a new batch file that can be launched either automatically or manually.

You can easily enable file checkpointing with automatic retry in the backup dialog in the NetBackup for SQL Server graphical user interface. Simply select a single database (or filegroup), then from the "Resume options for this selection" list, select Save work and restart at point of failure.

This action creates a batch file that contains the following scripting:

MAXRESTARTSETS 32
RESTARTWAITSECONDS 60
NUMRESTARTS 1

MAXRESTARTSETS 32 means that up to 32 pieces are backed up independently. The keywords RESTARTWAITSECONDS and NUMRESTARTS are synonymous with the following:

RETRYWAITSECONDS 60 
NUMRETRIES 1

These keywords indicates the following things: first, that an automatic retry is launched after 60 seconds for all of the pieces that failed to get backed up on the first time. Second, the restart is attempted only one time. You can manually change either of these parameters.

In addition, you can choose to not have the retry script automatically launched. Replace the NUMRETRIES command with RETRYTYPE MANUAL.

NUMRETRIES 1
with
RETRYTYPE MANUAL.

When manual retry is enabled, the generated batch file for the components that were unsuccessfully backed up is written to the following folder:

NB_INSTALL\dbext\mssql\temp folder

Note:

All of the keyword-value pairs that are described in this topic are only permitted in the first operation of the batch file.

More Information

File checkpointing