Quick Legato answer, long 'long term retension' answer:

For doing restores you do not need a Legato license, only for doing
backups. This is a feature of their disaster recovery process. No keys
needed to read back tapes. Let's you fixup the backups after the
disaster, not during.

Anyway for old tapes also consider doing things like cloning tapes now
and then to insure the drives and tapes still work. Many times this is
skipped. Also you may need to keep some old system because it's the only
one supporting the tape drive, etc...

Your other choice, to 'move' the data:

1. restore the data to somewhere.
2. use 'current' flavor of backup system to make new tapes.
3. repeat for all 'old' tapes.

This is used when your old hardware is dying (like only two of the old
drives are still working). Holding information for very long terms goes
through these dance steps many times. See how NASA keeps data from the
Mercury days, it isn't easy. Also some of the DOD regs have you copying
tapes every so often to insure they work and them haven't lost their
magnetism.

-- 
-ken cameron, CCP. Employer: Computer Task Group.
SkyDiver: Zoo-602, A-8596, D-11839.
Skier: down & cross. English Hunter Rider. Scuba: wet & dry
mailto: ken.cameron AT ctg DOT com  Home DZ: FingerLakes Skydivers, Ovid NY