I think that part of the problem is that you have drive/volume
expectations from Removeablefile devclass utilization, when in fact
its a file-based mechanism.  Two things you could do are to assure
that the devclass MAXCAPacity value is sized that that it has the
potential for writing a file as large as the capacity of your device
(file system), and that your Unix resource limit "filesize" is not
restricting the size.  Also beware file size limits for a chosen file
system type, which can be influenced by the block size chosen when the
file system was initialized.

As you have noted, there's scant info about Removablefile devclass.  I
tried a search on the new Support page which alleges to replace the
great TSM Support Page we once had - but the new Support page
programming has severe defects, where it won't show more than 20
search results, despite 190 hits.  (IBM's corporate self-delusion of
replacing something that worked well for the customer base with
something which satisfies corporate goals and nothing else.)

    Richard Sims