>ANR8301E I/O error on library 3494 (OP=005C6D37, SENSE=N/A, CC=00000023).

Bill - Here are my notes from http://people.bu.edu/rbs/ADSM.QuickFacts
       from prior experience.  Perhaps this may help.

ANR8301E I/O error on library ______ (OP=005C6D37, SENSE=N/A, CC=00000023).
        Seen when the mtlib status command shows a drive as "Device available to
        Library.", but ADSM finds itself unable to actually use the drive (an
        ADSM server 'SHOW LIBR' has it avail=0).  Attempted mtlib will show:
         mtlib -l /dev/lmcp0 -m -f /dev/rmt3 -V 000081
         Mount  operation Error - Device is not in library.
        In this case, look at the 3590 control panel: make sure that the drive
        is functional, and that the appropriate Path is Online.
        CC is the I/O completion code (some of which are documented in Appendix
        B of the Messages manual).

 Richard Sims, BU