Frozen - Netbackup application will freeze a tape if it has a problem with it, or you can freeze it manually. A frozen tape will not be use for any more backups. A frozen tape - when it reaches its expiration date will not show it. The images on the tape may still expire, but if you look at the GUI or command line the tape will still show its assigned date and other info. Once the tape is unfrozen, if all the images on the tape have expired, the tape will go to scratch. But if NetBackup froze the tape you want to see if you can find out why, as it may be bad and needs to be removed from the rotation.
Suspended - Netbackup application will NOT auto suspend a tape. You have to suspend the tape yourself. (this makes it easier to tell if NB had an issue with the tape - frozen- or if you wanted to save the tape). Once suspended the tape will not be used for any more backups.
The big difference here is that once all the images on the tape are expired, the tape will go unassigned and go back to scratch, avail to be overwritten by the next backup. Suspend can help you with putting a tape in a library to do restores from, preventing it from being appended to. But at the same time allows it to expired in a normal manner.
