Is there a way to access a VSAM file so we can create alerts when it gets a certain percent full?

Release : 13.5

Component : OPS/MVS

Perhaps you can can create a rule that invokes a REXX program and issue a LISTC to get information:

ADDRESS TSO
'LISTC ENT(vsam-data-set-name) ALL'
DO QUEUED()
PULL LINE
SAY LINE
END