[Info-vax] Exabyte tapes to disk

[Bob Koehler]

In article <h7p8ht$mgn$2 at naig.caltech.edu>, glen herrmannsfeldt <gah at ugcs.caltech.edu> writes:
> 
> It was not unusual to get two different densities on IBM systems.
> When you write a tape, you specify the density you want.  First
> the system verifies the label, in which case the drive adapts to
> the density.  Then it skips existing files, again at the density
> they were written at.  (It probably can find tape marks without
> actually looking at the data, but it does have to read the label.)
> Then new data is written at the specified density.

   I guess I never really tried, but I was never aware of any tape
   drive that would actually change densities in the middle of a tape.

   I do know that some DLT drives will turn compression on/off in
   the middle of the tape.  I've verified this on TLZ06.  And I think
   an engineer decided that was an "oops".