[Info-vax] Delete a file from a tape?

[glen herrmannsfeldt]

Richard B. Gilbert <rgilbert88 at comcast.net> wrote:
 
> There IS NO SUCH OPERATION as "DELETE" on a tape.  The best you can do 
> is to overwrite it or degauss the tape.  Degaussing the tape should be a 
> last resort with DLT tapes.  If you degauss a DLT tape you may not be 
> able to write it again; I think there is some sort of prerecorded track 
> on DLT-IV and maybe its successors!  IIRC that prerecorded track 
> synchronizes the "write clock" or some such thing.

My understanding is that DLT, at least DLT-IV, is safe to degauss,
and it is recommended in some situations.  Specifically, the DLT-1
drives won't successfully overwrite signals written by a DLT-4000
even though they use the same type of tape.  The only solution
is degaussing.

On the other hand, LTO does use an embedded servo and can't
be degaussed and reused.

-- glen