The Problem - Errors in filesystem prevented mounting of a 3TB SAN. The verification program I used (ravsui), failed to run due to memory limitations on 32-bit systems.
I knew VirtualBox supported 64-bit guests on 32-bit hosts but wasn't sure if it would be possible to access host partitions mounted in
/dev. Looking around, I found instructions (https://www.virtualbox.org/manual/ch09.html#rawdisk) on raw disk access.
With this setup, it was possible to create VMDK images corresponding to the host partitions and access them from the 64-bit guest. I was then able to run ravsui and fix problems with the filesystem.