On Fri, Nov 26, 2021 at 07:23:07PM -0500, Dennis Boone wrote:
>  > In my experience 9 track tapes were not guaranteed to be readable after
>  > some interval.  In fact, a standard operations procedure was to copy
>  > important tapes to new media periodically.
>
> There are always ways in which your backups can go wrong and not be
> readable, and I'm not arguing that here.
>
> But 9 track tapes have turned out to be pretty spectacularly long-lived.
> I've personally read tapes that were stored for 30+ years in
> unconditioned spaces.

Contrast that with the write only exabyte tapes.  I lost some stuff to those.