You need to build your copy of Perl with "large file support" enabled. This causes Perl to use 8-byte integers for items related to file size instead of 4-byte integers. This is only available on when building Perl on certain operating systems.

My overly quick search turned up:

Perl can be built to understand large files (files larger than 2 gigabytes) on some systems. To do so, Configure can be run with -Duselargefiles.

which should get you started.

        - tye (but my friends call me "Tye")