From: Paul Koning
When did Unix first get partitions?
'Partitions' the mechanism, or partitions the term for the mechanism?
The former appeared about V5:
when an RP03 was added; pre-V7, UNIX filesystems were limited to 2^16 blocks,
so the 406*10*20 blocks of an RP03 had to be split up into partitions (called
'sections' or 'pseudo-disks' in the documentation) to make all of it
The latter? No idea...
Partitions may have appeared in DOS/Windows for much the same reason; with 32
KB clusters, FAT16 filesystems were limited to 2GB. I distinctly recall
having to use partitions when I bought a 13GB hard drive for my Windows 95
machine (FAT32 only came in with Windows 95 OSR2).