The issue isn't the amount of memory, it's addressable space. LMDB maps all on disk data into memory. If that value exceeds the process addressable memory, you will get a critical failure. On 32 bit systems, process addressable memory maxes out around 2~3GB. Therefor, any file LMDB uses that exceeds 2GB in size cannot be created nor used on a 32bit system. This is a long winded way to saying please don't try this.