About the threshold for media errors

Each time a read, write, or position error occurs, NetBackup records the time, media ID, type of error, and drive index in the EMM database. Then NetBackup scans to see whether that media has had "m" of the same errors within the past "n" hours. The variable "m" is a tunable parameter known as the media_error_threshold. The default value of media_error_threshold is 2 errors. The variable "n" is the time_window parameter (default 12 hours).

If a tape volume has more than media_error_threshold errors, NetBackup takes the appropriate action.