pyramid 2 gig limit on backup

We run informix backups to a disk dataset on a nightly basis and then the disk is copied to tape later. We seem to have ran into a limit on the pyramid box that even though our file system is setting on a 4 gig disk and the kernel setting for file size is unlimited the backup fails when it reaches 2 gig. I was wondering if anyone out there had ran into this problem on a pyramid and may know what parameter to tune to let us write more than 2 gig into a file a once. We are running 6.0 on a Pyramid nile at 1.1-94d079 Thanks for your help. -- Tolly Brumbelow, Informix DBA email:tolly.brumbelow@bridge.bellsouth.com