When you add a drive to NetBackup, you configure the automatic, frequency-based cleaning interval. You can use the Device Monitor to change the cleaning frequency that was configured when you added the drive..
To set the cleaning frequency
In the NetBackup Administration Console, expand Media and Device Management > Device Monitor.
If an Enterprise Disk Option license is installed, select the Drives tab.
Enter a time (hours) or use the arrow controls to select the number of mount hours between drive cleaning.
Cleaning Frequency is not available for the drives that do not support frequency-based cleaning. This function is not available for shared drives.
The drive cleaning interval appears in the Drive Details dialog box (Actions > Drive Details).