Subject: Re: GPT guids
To: None <tech-userlevel@NetBSD.org>
From: Alan Barrett <apb@cequrux.com>
List: tech-userlevel
Date: 12/20/2007 12:03:40
On Tue, 18 Dec 2007, Greg Oster wrote:
> 1) Create a new disklabel type called FS_METADATA.
> 
> 2) A partition of type FS_METADATA would contain meta-data related to
> the filesystems/RAID/partitioning of the given disk, as specified by
> the disklabel.  Only one partition of type FS_METADATA is allowed per
> disklabel.  Only the first FS_METADATA partition will be used if there
> are more than one.

I prefer each raid partition to contain its own metadata (as at
present); I think der Mouse said it best:

" To me, the recursive way _is_ the simple way.  Why should a piece of
" disk found through a partition table be any different from a piece of
" disk that happens to be an entire hardware spindle?

However, I see the attraction of being able to convert from a non-raid
partition to a RAID-1 partition without having to shuffle gigabytes of
data a few blocks down the disk to make space for the metadata.  I'd
suggest addressing that by allowing a tiny partition to contain only the
raidframe metadata and a pointer to the partition where the real data is
(very similar to your FS_METADATA idea, but not restricted to only one
metadata partition per disk).

--apb (Alan Barrett)