Yap pretty big.
Allegedly this has already been running at Klarna in production for a while. LevelDB backend from Basho (eleveldb, it has extra optimizations and improvements besides just Erlang wrapper) has been used.
Granted 15-20 some years ago perhaps 2GB was BigData(TM) ;-)
For a while I understand you could set up sharding, so each shard is 2GB and spread shards across nodes.
This is a pretty big deal isn't it? I've never used Mnesia but that 2GB limit was a common warning I came across in the docs and blog posts, despite noting it was a great DB to work with.