The AppleTalk portions of your Novell server are working because your Macintosh users can see the server in the Chooser, connect by logging on, and print to the server's attached printers using AppleTalk.
There is no way to correlate the disk array's volume size to your problem, because the Macintosh computers have not yet mounted the volume. This is because the Novell server is not informing the Macintosh computers that there are any volumes attached. The volume selection dialog lists volumes in response to an AFP request, from the Macintosh to the server, for a list of attached volumes, not caring about the characteristics of the volumes.
Therefore at this stage, this appears to be a configuration problem on the Novell server. Any volume size issues will only emerge once the Macintosh users select the disk array, and attempt to mount it. Furthermore, any difficulties that may arise, when mounting the disk array, are not related in any way to the Macintosh computers inability to see volumes offered by the server.
You need to review the steps necessary to make the server's volumes available to Macintosh users. The multi-protocol Novell server needs each aspect of its services separately set up for each protocol supported -- a volume needs to be explicitly shared for IPX clients, AppleTalk clients, and IP clients.