Read $JUKE_DIR/config/client.cf and examine the entry for the jukebox you are interested in. It will refer to a permissions file, $JUKE_DIR/config/xyz.prm for jukebox xyz. That permissions file has three columns; the first colunn is the name of a file. Users have read and execute permission according to the read and execute permission on that file. The second column names a type of resource, either a SLOT, DRIVE, or PORT, or a permission like ONLINE or INIT. The third and forth coulumns specify the range of locations (if any) that the permission file affects.
So if you want to change the permissions on two of the tape drives in jukebox sga so only user "fred" can access them, first look at the client.cf file. It has an entry like
sga cdfsga config/sga.prm exabyte,/dev/scsi/sc0d7l0 dbm,sga tps0d2 tps0d3 tps0d4 tps0d5
So now we examine the file sga.prm, which looks like:
#perm item range
#---- ---- ----
config/rxrx SLOT 0-115
config/rxrx DRIVE 0-3
config/rx-- PORT 0
config/rx-- INIT
config/rx-- ONLINE
We need to make a separate entry for drives 0 and 1, and make them only readable and executable by fred:
#perm item range
#---- ---- ----
config/rxrx SLOT 0-115
config/rxrx DRIVE 0-1
config/fred DRIVE 2-3
config/rx-- PORT 0
config/rx-- INIT
config/rx-- ONLINE
and then create a file "fred" that is executable and readable by user fred.