8.0-RELEASE and "dangerously dedicated" disks

Polytropon freebsd at edvax.de
Wed Dec 2 18:25:25 UTC 2009


On Wed, 2 Dec 2009 13:09:22 -0500, Jerry McAllister <jerrymc at msu.edu> wrote:
> Good.   Except that in FreeBSD land you are talking about a slice table.
> To carry things forward consistently, the partition table is within
> a slice and describes FreeBSD partitions a..h (and more now I guess).
> Only in MS or Lunix land should primary divisions be called partitions
> and then they are _primary_ partitions.

To be most precise, they are called "DOS primary partitions".
As far as I know, the need for them has been massively by
MICROS~1 operating systems (DOS, "Windows").

That what FreeBSD calls partitions are subdivions of
slices. A partition holds a file system (each), while a
slice holds partitions. Those partitions could be compared
to what MICROS~1 calls "logical volumes inside a DOS extended
partition", allthoug that's just a *comparison* and not
an exact equivalent.



> But, even some of the fdisk and other documentation still mucks this
> up and occasionally refers to slices as partitions.   Maybe we can
> come up with some new terminology like  'blobs'  and  'dollops'  to get 
> away from the problem.

Borrow some artificially created fantasy words from modern
KDE or Gnome application development? :-)

An idea that follows your inspiration could be:

	(old) slice => (new) primary partition 
	eq. DOS primary partition

	(old) partition => (new) secondary partition,
		alt. (new) subpartition
	comp. logical volumes inside a DOS extended partition

But it would help to get at least FreeBSD's documentation
consistent, even if it uses the non-MICROS~1 names for
things (which is very fine for me).

Note that the limitation to 4 slices per disk - we remember
that we are talking about "DOS primary partitions" here -
is grounded in the fact that MICROS~1 stuff doesn't seem
to be able to handle more than 4, a legacy restriction from
the past. I've not yet tested if it's possible to create
e. g. ad0s1, ad0s2, ad0s3, ad0s4 and ad0s5 with FreeBSD,
but it should be possible.

(Because multi-booting PCs respectively their operating
systems eat up primary partitions like coockies, often
people complain that they can't install FreeBSD because
it requires a primary partition as well. Mostly, people
don't have 4 OSes on their disks, but the one or two
they often have (e. g. a Linux and a "Windows") have
already occupied adX0..adX3.)


-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...


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