HOW Long does 'mt -f /dev/nst0 erase' take

[KewlEugene]

I tried to erase an LTO2 tape with an IBM LTO2 drive. How long should it take ? with

mt -f /dev/nst0 erase

It ran for 50 minutes, I couldn't kill it, halt'ed ubuntu, and the IBM LTO2 drive kept running, I had to cycle power, then hit the eject button.

Is there a better way to erase these tapes.

(You can't degauss LTO2 tapes or they are permanently ruined).

[KewlEugene]

I waited for it to finish and it takes 2:34 to erase an LTO2 tape.

It takes 2:50 to write a full LTO2 tape with tar.

So when erasing the LTO2 tape it appears to write to the whole tape again.

[HROAdmin26]

Backup applications usually call this a "long erase" = write 0's to the whole tape. How else do you "erase" a tape? There is also a "short erase" or "label" where just the tape header is wiped. But of course that leaves the data recoverable.

Same issue as "erasing" an HDD...and does one pass really "erase" the date beyond all recovery?