It looks as if after creating more swap space (now 3Gb) and upping the ram (now 4gb), the database restore completed successfully.
The production database only contains 2Gb of RAM.
Mind you, it finished with;
root@prodsup01:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 19G 9.9G 8.2G 55% /
varrun 2.0G 1.8G 183M 91% /var/run
91% of varrun being full.
I dont know how to explain this problem since our production database is fine, with only 2Gb of RAM, mind you, I don't think anyones ever needed to restore to that database.
This does not bode well for ease of mind.
Edit - I have assumed that one of the tables/objects/something in the database to be restored required more resources to load. Unless anyone can come up with anything better, haha.