This is a really simple starter for ten, and was the 'failing memory' issue mentioned in the intro article. The command to list the active RACF database is not totally intuitive, although I'm sure that anyone that administers RACF on a regular basis (which I don't) would have no problem remembering it. Just issue:

RVARY

with no parameters (obvious, eh??). You can issue it from the console, by prefixing with the RACF subsystem command character (which defaults to a hash sign , ie. #RVARY), or as a TSO command. The output will look something like:

 ICH15013I RACF DATABASE STATUS:                         
 ACTIVE   USE    NUMBER   VOLUME     DATASET             
 ------   ---    ------   ------     -------             
  YES     PRIM      1     OS39M1     SYS1.RACFDS         
  YES     BACK      1     Z4RES1     SYS1.RACFDS.BACKUP  
 ICH15020I RVARY COMMAND HAS FINISHED PROCESSING.        

[BTW it seems ironic that this site has a category for Personal Computing, but not for Computing in general, hence this article is listed under Miscellaneous.]