We're looking for experienced advice considering whether to
        
  a)    upgrade our 3590 E1A drives to H1A drives and reuse
        our aging 3590 tapes for net gain of 50% more tape space

  b)    discard 3494 and 3590 technology and replace w/ LTO-2 or
        LTO-3 drives and media, expanding our existing 3584 ATL's
        currently filled w/ LTO-1 media and mixed LTO-1/2 drives.

If you have considered or done one of these conversions, we would
like to hear from or talk with you.  If you don't feel like writing
a reply, please send me a phone# and we'll try to call you.

Yale University started using 3590 tapes 8 years ago in 1996.
We now have two 3494 ATL's, each w/ six 3590 E1A drives,
and about 4000 J tape cartridges, most of them 6-8 years old.
The warranted life of a 3590 cartridge is 10 years, so...
we are wondering what other sites are thinking/doing about
your aging 3590 media and hardware.

To date, our actual 3590 media failures are insignificant:
about 40-50 tapes over the 8 years or 1-2% real failed media.
[But how much longer can we expect them to last:  5-10 yrs?]

That's eliminating all of the "false" failures where the 3590
drive actually was at fault; if the tape passes an AUDit Volume
and doesn't get errors on another drive, we UPDate the volume
back to ReadWrite status and keep on using it, unless it fails
again!  We also re-attach leader blocks, if they get pulled off,
and continue to using the tape if it loads OK.  We've only had to
fix 6 of those, but 3 became detached during the past 2 weeks!

We've had a rough two weeks with one of our 3494 ATL's, but
problems seem to occur in fits and spurts.  After a few months
w/ no problems, we've called IBM 8 times during the past week to
service 3590 problems in our busiest 3494 (but had no problems
w/ the other one!)

During the busiest hours of each afternoon (migrating small
clients' backups from disk to collocated 3590 tapes) each
of the six 3590 drives mounts (and dismounts) 20 tapes/hr or
120 tapes/hr for the 3494 robot. The library is typically
that busy for 5-7 hours each day, then much less busy for the
rest of the day and night, mostly doing 3590 tape reclamations.

Please advise, if you have experience to share.
Thanks for your help.
--
Jim.Owen AT Yale DOT Edu   (203.432.6693)