All of this discussion concerning primary backup to tape ignores the 
unreliability of tape, particularly
as a primary storage medium.  Because tape is tape, because it does require 
sequential access, because the
access - no matter the size/type/robotics/capacity - is slow, because it 
doesn't store well, because it
wears out fast, ad infinitum. Tape should not be used as a primary storage 
medium.  It is only effective
when data is streamed to the tape from beginning to end.  When you begin trying 
to use tape as you would
disk you are exceeding the capability of the system and setting yourself up for 
a fall.

Tape is ideal for making a one-time copy, for off-site storage or emergency 
recovery.  It is the wrong
medium for ADSM, or any read/write database application.

Use disk - optical, or magnetic - where it is necessary.  Attempting to use 
tape in its place is a false
economy.  You will lose your customer's data and will have saved only pennies.


Paul C. Beck
Manassas Systems Integration Corporation
Traveling at OS/2 Warp speed....