Why does a backup job in Backup Exec prompt for more media when there is overwritable media mounted in the device chosen as the destination

Problem

During a backup job, Backup Exec may prompt for overwritable media to finish the job.  If the user reviews the list of mounted media, it shows that there is overwritable media in the device.

Error Message

Please insert overwritable media into the drive.

Overwritable media includes scratch, blank, and recyclable media.  Please note that depending on the current Media Overwrite Protection setting, import and allocated media may be overwritable as well.  Consult the online help for more information on overwritable media.

Respond Yes to acknowledge.
Respond No to retry the operation.
Respond Cancel to cancel the operation.
 

Cause

When configuring the backup jobs and the media set rules for overwrite protection / append periods, the chosen settings can cause the jobs to always append to the media.  This will cause the backup jobs to span across multiple media (tape or disk).  When a job spans to more than one piece of media to complete the job, this causes those media to be joined to a MEDIA FAMILY (Media that have backup sets that span across multiple media).  A MEDIA FAMILY can grow to encompass a large amount of media when using APPEND jobs.  We do not recommend using APPEND jobs unless attempting to use a single media to contain more than one backup set.

Solution

In order to prevent the backup jobs from getting hung trying to find overwritable media to write to, the following are recommendations that can be used when configuring MEDIA SET properties and BACKUP JOB properties.

• DO NOT use either of the below types of jobs unless attempting to use a 'single media' to contain more than one backup set.
  • Append to media, overwrite if no appendible media is available
  • Append to media, terminate job if no appendible media is available
• DO NOT leave the append period of the chosen media set for the job as INFINITE ALLOW APPEND.  This will allow the media / drive to fill up to capacity and then the prompt for more media will occur.
• DO NOT set the overwrite protection period for a time that exceeds the necessary retention needed or it will not be overwritable when the job tries to overwrite the media the next time in the rotation.
• Ensure that the media in the destination device that the job is going to use is available to be overwritten before the job starts or make sure that there is available free space to run the job to the destination device.
• Ensure that the destination device is free from errors (disk write errors or tape hard / soft errors).  This will cause the media to store less than expected and up to even damaging the media which will cause data loss.