gmirror, gpart and MBR vs GPT in the Handbook

[Warren Block]

On Sun, 1 Dec 2013, Mike. wrote:

> On 11/30/2013 at 2:17 PM Warren Block wrote:
>
> |On Sat, 30 Nov 2013, Mike. wrote:
> |
> | [snip]
> |
> |> Is there a specific reason why MBR was used in the Handbook
> |> example for creating a mirror, instead of GPT?
> |
> |Yes, there was, see the last paragraph of the Metadata Issues
> |subsection,
> |http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/geom-m
> irror.html#geom-mirror-metadata
> |
> |[snip]
> =============
>
>
> A question about the wording of that paragraph.  The second
> sentence states:
>
> "Because GPT partition schemes also store metadata at the end of
> the disk, mirroring full GPT disks with gmirror(8) is not
> recommended."
>
>
> The word "full" is ambiguous.  Is it to mean, "full" as in 'full
> of data', or "full" as in 'the entire disk'?

It means mirroring an entire disk, including boot blocks and metadata, 
rather than just parts of it like partitions or filesystems.

I'll work on rewriting that paragraph for clarity.