Amiga Hard Drive size limitations

[Zac67]

Exactly. As soon as a partition overlaps the 2^32 bytes barrier the data written to the overlapping  sectors will wrap around and destroy your RDB, the beginning of your first partition etc.

With a slightly-over-4GB drive it's not worth the trouble but otherwise check http://www.youngmonkey.ca/nose/articles/NewTekniques_9810/AmigaInMotion.html