I do backups to a HP Ultrium 2 tape drive (HP StorageWorks Ultrium 448). The drive has a 'Clean' LED that supposedly will light up or blink when the drive needs to be cleaned.

The drive has been in use since october 2005, and still the 'Clean' light has never been lit.

The drive statistics are:

• Total hours in use: 1603
• Total bytes written: 19.7 TB
• Total bytes read: 19.3 TB

My question is:

• How many hours of use can I expect before I need to clean the drive?

Edit: I have not encountered any errors using the drive. I do restore tests every two months, and every backup is verified.

Edit 2: The user manual says: "HP StorageWorks Ultrium tape drives do not require regular cleaning. An Ultrium universal cleaning cartridge should only be used when the orange Clean LED is flashing."

Update: It is now May 2010 (4.5 years of use), and the LED is still off, I have not cleaned, backups verify and regular restore tests are done.