Problems rotating external USB disks (BE 2012)
I have configured my storage pool as outlined in https://www-secure.symantec.com/connect/articles/how-rotate-external-harddisks-be-2012. The USB disks had Disk Storage created on them, not Disk Cartridge Device.
The problem is that when the disks are swapped, the new disk is marked with the "pencil with cross image" (https://www-secure.symantec.com/connect/forums/what-reason-pencil-image-storage-tab-be-2012) and backup jobs scheduled to run after the swap do not run.
The disks are swapped while Backup Exec is idle and the Safely Remove Hardware tool is used.
The only workaround I've found is to remove the USB disk from the storage pool, delete the disk storage, create the disk storage, inventory and catalog, and add the disk to the storage pool.
BE 2012 has a feature to write-protect storage which has been offline for prolong periods of time.
After the disk come online, you can remove the write-protection by right-clicking on the disk storage and changing the "Limit BE to read-only operations" (2nd property) from Yes to No.
Alternatively, you can change the period before the disk storage becomes write-protected. Click on the BE button ---> Configuration and Settings ---> Backup Exec Settings