What is the logic used by netbackup to freeze the media

Netbackup uses the parameters TIME_WINDOW and MEDIA_ERROR_THRESHOLD to determine if a media has to be frozen.

- Netbackup freezes media on the third time a error is ecountered in 12 hours on a media.

- Default Media Error threshold is 2 and time window for error is 12 hours

If you wish change above parameters can be tuned as follows

in Netbackup 6.x

nbemmcmd -changesetting -machinename <hostname>  -TIME_WINDOW <no. of hours>

nbemmcmd -changesetting -machinename <hostname> - MEDIA_ERROR_THRESHOLD <value>

If you wish to check the error files can be checked from 

Netbackup records the failure(write failure, position error) on every media server at the following location

On unix:

/usr/openv/netbackup/db/media and the file name is errors.

On Windows:

install_path\Netbackup\db\Media and the file name is errors.