>But what I think think happens is that the second disk just has
>the OS/2 and the Library Manager software and *not* the database.
>So if you lose the PC, the engineer can boot the 3494 on the
>second disk.

According to the redbook "3494: A Practical Guide" that I cited yesterday:
The primary hard disk drive contains the OS and one copy of the library
database.  Without the HA1 feature, the second disk contains only a second
image of the db...  Failure of the primary disk causes the library to cease
functioning, but after the disk is replaced and the OS reinstalled and
reconfigured, the image of the lib db on the second disk can propagated to the
primary disk.

HA1 give you an internal LAN and two library managers with their own copies of
the OS and db on their primary disks. Failure of one LM causes fallover to the
other one, and the library continues functioning.

Lots of options and lots of possibilities now.  You can also make the library
double-ended and have Rock-em, Sock-em robot events.  ;-)

    Richard Sims, BU