freebsd stable - Jan 2010 - 8.0-RELEASE / gpart / GPT / marking a partition as "active"

It seems that quite a few BIOSes have serious issues booting off disks
using GPT partitioning when no partition present is marked as
"active". See
http://www.freebsd.org/cgi/query-pr.cgi?pr=115406&cat=bin
for a prime example.

In 8.0-RELEASE, using gpart, setting a slice as "active" in MBR
partitioning mode is trivial, ie:

gpart set -a active -i 1 DISKNAME

However, trying to do the same thing with GPT partitioning yields no results:

gpart set -a active -i 1 DISKNAME
gpart: attrib 'active': Device not configured

As a result of this issue, I can configure and make a succesfull
install using GPT in 8.0, but I cannot boot off it using my Intel
D945GCLF2 board.

I have found this discussion from about a month ago:
http://www.mail-archive.com/freebsd-stable@freebsd.org/msg106918.html
where Robert mentions that "gpart set -a active -i 1" is no longer
needed in 8-STABLE, because the pmbr will be marked as active during
the installation of the bootcode. Is there anything I can do to
archieve the same result in 8.0-RELEASE or is installing from a
snapshop of 8-STABLE my only option?

Thanks.

- Sincerely,
Dan Naumov

on 19/01/2010 19:11 Dan Naumov said the following:
> I have found this discussion from about a month ago:
> http://www.mail-archive.com/freebsd-stable@freebsd.org/msg106918.html
> where Robert mentions that "gpart set -a active -i 1" is no
longer
> needed in 8-STABLE, because the pmbr will be marked as active during
It was never ever "needed", because it never worked.
> the installation of the bootcode. Is there anything I can do to
> archieve the same result in 8.0-RELEASE or is installing from a
> snapshop of 8-STABLE my only option?
People did it using fdisk -a, google should have turned that up.

-- 
Andriy Gapon

On 1/19/2010 12:11 PM, Dan Naumov wrote:
> It seems that quite a few BIOSes have serious issues booting off disks
> using GPT partitioning when no partition present is marked as
> "active". See
http://www.freebsd.org/cgi/query-pr.cgi?pr=115406&cat=bin
> for a prime example.
>
> In 8.0-RELEASE, using gpart, setting a slice as "active" in MBR
> partitioning mode is trivial, ie:
>
> gpart set -a active -i 1 DISKNAME
>
> However, trying to do the same thing with GPT partitioning yields no
results:
>
> gpart set -a active -i 1 DISKNAME
> gpart: attrib 'active': Device not configured
>
> As a result of this issue, I can configure and make a succesfull
> install using GPT in 8.0, but I cannot boot off it using my Intel
> D945GCLF2 board.
>
> I have found this discussion from about a month ago:
> http://www.mail-archive.com/freebsd-stable@freebsd.org/msg106918.html
> where Robert mentions that "gpart set -a active -i 1" is no
longer
> needed in 8-STABLE, because the pmbr will be marked as active during
> the installation of the bootcode. Is there anything I can do to
> archieve the same result in 8.0-RELEASE or is installing from a
> snapshop of 8-STABLE my only option?
After using gpart to create the GPT (and thus the PMBR and its 
bootcode), why not simply use "fdisk -a -1 DISKNAME" to set the PMBR 
partition active?

On Tue, 2010-01-19 at 19:11 +0200, Dan Naumov wrote:
> It seems that quite a few BIOSes have serious issues booting off disks
> using GPT partitioning when no partition present is marked as
> "active". See
http://www.freebsd.org/cgi/query-pr.cgi?pr=115406&cat=bin
> for a prime example.
> 
> In 8.0-RELEASE, using gpart, setting a slice as "active" in MBR
> partitioning mode is trivial, ie:
> 
> gpart set -a active -i 1 DISKNAME
> 
> However, trying to do the same thing with GPT partitioning yields no
results:
> 
> gpart set -a active -i 1 DISKNAME
> gpart: attrib 'active': Device not configured
> 
> As a result of this issue, I can configure and make a succesfull
> install using GPT in 8.0, but I cannot boot off it using my Intel
> D945GCLF2 board.
I have the same board... 
> I have found this discussion from about a month ago:
> http://www.mail-archive.com/freebsd-stable@freebsd.org/msg106918.html
> where Robert mentions that "gpart set -a active -i 1" is no
longer
> needed in 8-STABLE, because the pmbr will be marked as active during
> the installation of the bootcode. Is there anything I can do to
> archieve the same result in 8.0-RELEASE or is installing from a
> snapshop of 8-STABLE my only option?
Prior to fixing gpart to take care of this, I used fdisk to set the
active partition.  gpart knows the disk is GPT and GPT doesn't have an
"active" parameter, so the above command doesn't (perhaps never)
worked.

Basically, an "fdisk -a /dev/devX" is what you want...

robert.
> Thanks.
> 
> - Sincerely,
> Dan Naumov
-- 
Robert Noland <rnoland@FreeBSD.org>
FreeBSD