Put the system in single user mode: init 1
Use fdisk to allocate 2Gigs to a new partition. Open fdisk with the existing HD name /dev/hda (or whatever). Use the 'a' key to add a new partition. Select the next partition number. If this will be the second partition on the drive then it will be 2. Next select the starting block. Use the default, it should be the next available. Then select the size. +2000M will be 2Gig. Write you configuration with 'w'. cd to the / directory. Create a new directory called /export. Modify your /etc/fstab to mount the new partition on /export on startup.
/dev/hda2 /export ext2 defaults 1 1
Reboot and it should mount when it comes up.