Dell NetWorker 19.9 Administration Guide

The importance of writers

Writers play an important role in correctly backing up data. They provide metadata information about what data to back up, and specific methods for correctly handling components and applications during backup and restore. They also identify the type of application or service that is being backed up. Writers do not play a role in backing up the file system.

Writers are currently only available for active services or applications. If a service or application is present on a system but is not active, information from its writer is not available. Consequently, a writer can appear or disappear from backup to backup.

Also, NetWorker software maintains a list of supported writers in the NSRLA database of the client computer. When backing up data, the software checks to ensure that these conditions exist:

• The writer that is associated with the application is present on the system and active.
• The writer appears on the list of supported writers in the NSRLA database.
• A user has not disabled the writer.

If these conditions are all true for a particular writer, NetWorker software defaults to backing up data by using VSS technology. If any of the conditions are false for a particular writer, the data that is served by that writer is excluded from the backup operation.