preserving partitions... again

[Toomas Tamm]

On Sun, Jan 23, 2011 at 01:37:47PM +0100, Thomas Lange wrote:
> >>>>> On Sat, 22 Jan 2011 11:13:40 +0200, Toomas Tamm <tt-fai at kky.ttu.ee> said:
> 
>     > I think I have found another strange disk layout which setup-storage
>     > cannot preserve. Here, the extended partition /dev/sda3 is physically
>     > located between sda1 and sda2.
> I'm not sure if FAI needs to support this strange layout. Is it
> sufficient to support only layouts so that sdN is always physically
> localted before sd(N+1)?

Such layouts occur when one tries to install Linux onto computers
(both desktop and laptop) with Windows pre-installed, and where the
manufacturer has installed a recovery partition at the physical end of
the disk. Usually such computers come without any installation media
and the standard way to (re)install Windows is to boot into the
recovery partition. Thus this partition needs to be preserved. The
recovery process involves pressing a hotkey (eg F11) at boot time and
I would be very reluctant to re-number partitions and hope that the
hotkey processing would not have the partition number hard-coded.

If a dual-boot machine is the goal, the usual procedure is to shrink
the primary Windows partition, creating empty space in between, which
can then accommodate an extended partition where logical partitions
for Debian can be created.

Until now I had always dealt with systems where the recovery partition
was sda4, but this particular laptop had it as sda2. Thus I had to
squeeze sda3 physically in front of sda2. I am not asking FAI to be
able to create such layouts, just being able to preserve what is
already there is sufficient.

Regards,

Toomas