Haai,

On Wed, June 6, 2007 04:31, Bill Stouder-Studenmund wrote:
>>[snip]
>
> Yes.

No.

>
> MBR, Apple partitoin maps, and disklabel labels all use 32-bit nubmers to
> count sectors. Thus they have issues with disks larger than 2 TiB (2^32
> blocks). You can play games with block sizes, but that will get you only
> so far. And it will be very non-portable.

And why not just introduce a new, limitless, copy-on-write disklabel? We
have something that fits perfectly in our system, and I see no reason to
change it. Funky mapping and such can all be done on a higher level.

> As far as I can tell, Windows and Mac OS have standardized on GPT for such
> disks, and I think Linux also uses only GPT for them. Thus GPT is the
> choice for such disks.

I hope that last sentence was intended to mean 'for disks which, by some
strange logic glitch, use GPT and need to multi-boot'...

> So we need GPT regardless of what else we may do.

It would certainly improve compatibility, but I don't see why we should
use it ourselves. The BSD disklabel fits in perfectly with our system and
I see no reason at all not to improve it instead of switching to a
generic, bloated solution on this low level.

>
> Given that we need GPT, it makes sense to use it as a way to clean up a
> number of other issues. GPT, especially with wedges, is not limited to a
> fixed number of partitions. It's been designed to not have a number of
> issues we've faced with our current labeling options.

The real problems, like overhead and OS device addressing, still remain.

>
> GPT maps also have the advantage that all OSs can understand the
> partitions. Yes, not much other than NetBSD will understand our file
> system, but Windows and Mac OS and Linux will know where our partitions
> start and end.

Windoze will /not ever/ interpret most types of disklabels, and we all
know the reason. As for the Unices, Lunix can do it already. Not sure
about Darwin, though. Then again, our code is wide open and anyone can
copy it.

> So if you end up needing to reclaim a partition while
> running another OS, you can.

The chances of that happening on any serious system are to the point of
non-existence.

Baai,

De Zeurkous
-----------

Friggin' Machines!

>
> Take care,
>
> Bill
>