At 04:17 PM 11/11/98 -0500, Mark Dyer wrote:
>DLT is an Industry standard, not an IBM standard.

Not really, but there is a point to be made here.

Like 8mm, DLT robots are offered by many vendors.  All drives come from one
source (Quantum for DLT and Exabyte for 8mm).  There *is* a new tape
standard evolving, called LTO (Linear Tape Open) (or is it OLT?).  This is
being pursued by a number of vendors including IBM, Seagate, HP, and
probably others.  Quantum is not in this group (last I heard).

One point to consider is capacity growth options, including both storage
capacity and drive availability.  As your system grows, you will
undoubtedly be faced with upgrade decisions.  Consider the cost of
upgrading.  Upgrades come in several flavors:

1. Add drives.       IBM drives are much more expensive than DLT.
2. Add tape slots.   Not sure who wins here.
3. Upgrade density.  Again, IBM drives are more expensive, so DLT wins
here.
4. Upgrade tape.     I.e., use longer tapes.  This is IBM's latest upgrade
for
                     3590.  This can be very expensive.

IMHO, DLT has a better story to tell when upgrading.  Their drives have
been backward compatible for several generations, meaning that newer drives
read older tapes.  Because their drives are cheaper, it is less expensive
to upgrade them to gain capacity.  Both formats have very high-end robots,
allowing you to add slots as a way of gaining capacity.

DLT loses on data access times, and *perhaps* reliability.  I have heard
lots of stories about DLT problems, and we have had our share.  I haven't
seen a fair comparison of DLT vs IBM regarding reliability.

So, if you can afford it, go for IBM.  BUT: Beware of a deal that gives you
a low entry cost - you may end up paying more in the long term when you
upgrade your system.  This is what steered us in the DLT direction.  We had
an opportunity to buy a used 3494/3590s at a very good price, but when we
looked at our estimated 5-year growth, the 3590 solution ended up looking
more expensive.

..Paul