Origin of "partition" in storage devices

[Paul Koning]

> On Jan 31, 2022, at 7:35 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
> 
>> From: Tom Gardner
> 
>> You define logical disks by assigning a logical disk unit number to a
>> file on a physical disk. You can then use the logical disk as though it
>> were a physical disk.
> 
> To me, 'partition' implies a contiguous are of the disk; "a file" to me
> implies that it might not be contiguous? Or are files contiguous in the RT-11
> filesystem? (I know there were filesystems which supported contiguous files.)

Yes, RT-11 is a somewhat unusual file system in that it doesn't just support contiguous files -- it supports ONLY contiguous files.  That makes for a very small and very fast file system.

The only other example I know of that does this is the PLATO file system.

As for partition vs. file, the two differences I see are: (1) layering: the partition is below the file system.  (2) partitions are originally entirely static (set at creation and never changed) and even later on changed only rarely and typically with substantial technical difficulty.

	paul