On Thu, 14 Dec 2006, Frank Smith wrote:

AIT5 recently came out, and it can read AIT3 and AIT4 tapes, and has
400GB native capacity.

Interesting.  I followed up on this and it appears to be true.  So, we
will consider upgrading our Qualstar AIT2 library with AIT5 drives at
some point.  Still, we're going forward with our LTO3 library purchase
at this point.  The one failure I see in reading the AIT5 specs is that
is it 400 GB native capacity but still 24 MB/sec transfer rate, same as
AIT4.  So it will take nearly 5 hours to write a tape at full speed.

After waiting forever for AIT3 to get out the door, and after then
being promised that AIT4 would be backwards compatible, only to find
out it wasn't sometime AFTER it was released, we've lost all loyalty
to the AIT line.

   Unless you frequently have a need to read old tapes, keeping a
an old drive or two around just to read old tapes isn't a big deal.

I gotta disagree with this though.  Keeping an old AIT drive around
to be able to infrequently read old tapes is a recipe for disappointment.
Old AIT drives' capstans eventually fail and lead to drive errors.  If
you want to read old AIT tapes, either use a modern drive with backwards
read compatibility, plan on having to refurbish that old drive you're
keeping around every now and then, or migrate the data to modern media.

The advantage of not switching formats is that you can just replace
the drives and the tapes to upgrade a library to higher capacity.

Agreed.  Which is the only reason we will consider buying AIT5 drives
now, because we already have an AIT2 and an AIT3 library.  AIT4 was,
apparently, just a very bad dream.

-Mitch