Dangerously Dedicated

[Polytropon]

On Thu, 10 Dec 2009 00:04:28 -0800 (PST), James Phillips <anti_spam256 at yahoo.ca> wrote:
> The Detailed 8.0 release notes don't say anything about bootability:
>         2.2.5 File Systems
>           “dangerously dedicated” mode for the UFS file system 
>         is no longer supported
>  http://www.freebsd.org/releases/8.0R/relnotes-detailed.html

Okay, but what happens when you

	# newfs /dev/ad1

in the assumption that ad1 will be a pure data disk, and
issuing this command will create a partition covering the
whole ad1 disk without any slice, and then create an UFS
file system in this partition?

I cannot imagine that this shouldn't be possible anymore.
I'm convinced that abandoning DD for bootable disks is
completely understandable, but...

Where are the points when problem occur?

(I've got no 8.0 installation at hand so I can't check this
in a live setting.)



> I also note that the DOS partition (slice) table is not explictly 
> required either: could you use an Apple partiton (slice) table 
> instead? 

I don't know how they differ from each other.



> Of course, if you are just storing raw data, you don't always *need* 
> a filesystem. 

You can of course simply use tar (as the "most universal file
system, at least among UNIXes") on a raw disk, e. g.

	tar cf /lots/of/files /dev/ad1

and retrieve it using

	tar xf /dev/ad1

But in the common case of a pure data disk, as I mentioned
it above, you have a file system (inside a partition), but
no slice. In such a case, the fdisk utility will show a
sysid 165 partition for the disk, just as if a slice would
be present.



I'm interested in knowing where this will end. FreeBSD
defaulting to FAT file system for maximum compatibility?
Don't mind, just a joke. It will of course use NTFS. :-)




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