Quick Scan Report – Backup To NUL

SQL Server has an option where the backup filename can be replaced with NUL. This is telling SQL Server to go through the process of backing up the file, but don’t write anything to disk.

This can be dangerous as it may appear that you have backups where in reality there are not any valid backups to use if it is being backed up to NUL.

Backing up a database to a null device in SQL Server is generally considered a bad practice because it serves no useful purpose. A null device is a virtual device that discards any data that is written to it, so backing up a database to a null device essentially means that the backup operation is being performed but no actual backup is being created. This can be confusing and misleading, as it may appear to the user that the backup has been successful when in fact no backup has been made.

There are a few potential reasons why someone might consider backing up to a null device in SQL Server:

  1. As a test or debugging tool: In some cases, a developer or DBA might use a null device as a way to test or debug a backup script or process without actually creating a backup file. This can be useful for verifying that the script or process is functioning correctly without the overhead of creating a large backup file.
  2. To reduce the amount of disk space used: Backing up to a null device can also be a way to reduce the amount of disk space used by backups, as no actual backup file is being created. However, this is generally not a good reason to use a null device, as there are other ways to reduce the size of backup files (such as compression) that do not involve discarding the data being backed up.

In general, it is better to create a real backup of a database rather than backing up to a null device. This ensures that you have a copy of the data that can be restored in the event of a failure or disaster.