change it in the device class with
upd devc blah mountr=#
where # is the number of minutes...

tsm: TSMSRV06>q dev 3590devc f=d

             Device Class Name: 3590DEVC
        Device Access Strategy: Sequential
            Storage Pool Count: 3
                   Device Type: 3590
                        Format: DRIVE
         Est/Max Capacity (MB): 0.0
                   Mount Limit: DRIVES
              Mount Wait (min): 30
         Mount Retention (min): 2
                  Label Prefix: ADSM
                       Library: TSM3494LIB6
                     Directory:
                   Server Name:
                  Retry Period:
                Retry Interval:
Last Update by (administrator): ZHVN04
         Last Update Date/Time: 06/28/01   07:52:35


tsm: TSMSRV06>