Lemme run this past you all and see if you can see holes in this plan.

We've got a 1000+ LTO-1 tapes in a library with a bunch of LTO-1 drives.
Nice, right?

Nope - there's a plan to convert the whole mess to LTO-2, abandoning the
LTO-1 drives but not the LTO-1 tapes.

HCART1 & HCART2, right?  Well, no.  We want to keep using the LTO-1 tapes in
the (supposedly backward-compatible) LTO-2 drives.

So, here's the plan:  

Put the LTO-2 drives into the library as HCART drives (just like our current
LTO-1 drives).  DO NOT add any LTO2 media until all the LTO-1 drives are
removed.  This will keep the LTO2 tape from being used by an LTO1 drive.

Only when all drives are replaced with LTO2 do we add any LTO2 media (also
as HCART media - same as our LTO1).  The plan is to use the auto-sensing
technology in the drives.  If an older LTO1 tape is mounted in the LTO-2
drive, we plan that the drive will dumb-down to LTO-1 to read and write.  If
the LTO-2 drive gets a newer LTO-2 tape, we plan that it'll write at LTO-2
densities and speeds.  Over time, we'll transition all the LTO1 media out
and replace it with LTO2 media (we're really after the speed and not the
density benefits of LTO2).

So - this hinges pretty heavily on the ability of the drive to auto-sense
the tape type and change its behavior - a feature I'm pretty sketchy on.

Comments?
-M

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  There are 10 kinds of people in the world,
  those that know binary, and those that don't.
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  Mark Donaldson - SA - Corporate Express
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