Yep, just define a devclass like and use it... (I set the est/max capacity
to the size of the filespace)
tsm: >q dev flatfile f=d

             Device Class Name: FLATFILE
        Device Access Strategy: Sequential
            Storage Pool Count: 0
                   Device Type: FILE
                        Format:
         Est/Max Capacity (MB): 2,048.0
                   Mount Limit: 1
              Mount Wait (min):
         Mount Retention (min):
                  Label Prefix:
                       Library:
                     Directory: /usr/adsm
                   Server Name:
                  Retry Period:
                Retry Interval:
Last Update by (administrator): SERVER_CONSOLE
         Last Update Date/Time: 08/09/2001 10:04:06