How about sending that backup directly to tape?
MV

        -----Original Message-----
        From:   Noha Safy El-Din [SMTP:nsafy AT IDSC.GOV DOT EG]
        Sent:   Monday, December 20, 1999 4:53 PM
        To:     ADSM-L AT VM.MARIST DOT EDU
        Subject:        UDB compression on OS/2

        Hello Everybody,

        We have recently migrated from DB2/2 v 2.1 to UDB v 5.2
        on an OS/2 platform.
        The size of our database is 2.3 GB. The size of our backup pool
        is 1.4 GB. We use compress always for our node.
        In the previous release of DB2, we were able to backup our
        database to this storage pool because the size of the backup with
        compression is reduced to about 40% of its original size. Therefore,
        in this case we were able to easily backup a 2.3 GB database into
        a 1.4 GB storage pool.
        When we migrated to UDB v 5.2, backup fails because of lack of space
        on this storage pool (backup does not start when it finds that the
        estimated size exceeds the size of the storage pool and its
successors).
        Does anybody have an idea about how to overcome this problem?

        thanks a lot

        Noha