The date to which we are referring
is the date that you see in vmquery, and is the date that the volume itself
should be expired, and no longer used. This is not related to the
expiration date of the images on the tape.
vmchange -M master -h volhost -exp 0 -m mediaid
The command above will tell
media manager that the tape should never expire.
vmchange -M master -h volhost -exp mm/dd/yy
-m mediaid
This will set it to expire
on a specific date.