broken partition layout with Thinkpad predesktop area

[Arthur Taylor]

Installed Hoary preview i386 last night. Installation went smoothly, operating
system detection worked (detected WinXP and previous Fedora install). Grub
installed to /dev/hda MBR. On reboot, the Thinkpad (R40) BIOS complained that
the partition layout was invalid and refused to boot. On-screen BIOS prompt
suggested disabling the 'Pre-desktop area' (where the XP factory image is / was
stored), which I did in BIOS setup, and that worked. I've never had to do that
before though, and have installed debian, Fedora, and FreeBSD using both Grub
and Lilo. I'm guessing the pre-desktop area is now gone, but haven't tried
reenabling it incase I lose data.

The new partition layout is (on a 40 gig drive):

/dev/hda1 (boot) 1 15510 NTFS
/dev/hda2 15511 43446 Linux (FC3 /)
/dev/hda3 43446 71400 Extended
/dev/hda5 70089 71398 Swap
/dev/hda6 43446 71400 Linux (Hoary /)
/dev/hda7 67416 70078 Linux (Hoary /var)

Other information - partitions 1,2,3 are listed as 'not end[ing] on cylinder
boundary' by fdisk. This I blame on the FreeBSD 5.2 partitioner with which I
partitioned the drive previously. Previously, /dev/hda3 was a BSD slice and I
used fdisk from Fedora to repartition to the current arrangement.

So apart from that scare, everything's fine for me but I wouldn't want to put
other users through the stress.

[Colin Watson (cjwatson)]

It seems much more likely to be a parted issue than a grub issue. Unfortunately,
nobody on the net seems to know the answer to this one ...

[Arthur Taylor (arthur-taylor)]

Just to check we're working on the same information here, I did the actual
repartitioning with fdisk from my FC3 install, not from the ubuntu installer.
Subsequent to the fdisk repartitioning, the machine booted fine. The only work
the ubuntu installer should have done was formatting the partitions hd6, hd7,
and hd5 with reiserfs, reiserfs, and swap, and installing the MBR / bootloader.
Obviously, though, you know more about what it does in practise than I.

The only slight caveat with that is that I _may_ have gone straight from
repartitioning in fdisk to booting from CD-ROM (it was a couple of days ago
now), so potentially I wouldn't have noticed if fdisk had screwed the partition
table. Having said that, the BIOS warning came up fairly early in POST (i.e.
probably before CD spin-up) so I would guess that the Thinkpad makes the sanity
check every boot, even in the presence of a bootable CD-ROM. I'm also fairly
paranoid about repartitioning usually, and I think I remember booting XP and
Fedora to make sure I hadn't destroyed them before restarting the ubuntu
installer. Sorry to introduce an element of doubt, but I wouldn't want to have
you chasing a ghost on my account. If other Thinkpad users aren't able to
reproduce, I'm happy to put it down to fdisk making a mess of deleting the BSD
slice / creating the extended partition.

[Colin Watson (cjwatson)]

In practice the process of running through the Ubuntu partitioner generally
causes parted to commit its current idea of the partition table to disk, even if
you didn't change anything. This *should* be a no-op if things are sane, but ...

[Paul Dufresne (paulduf)]

"Predesktop Area is the name used for two different technologies: Hidden Protected Area and Rescue and Recovery."
http://www.thinkwiki.org/wiki/PreDesktop_Area

Seems to be an HPA situation.
Which basically, is an hidden by BIOS primary partition at the end of HD, made to help restore the "other" OS.

HPA is somehow, the previous technology before Rescue and Recovery which is just a plain partition not hidden by BIOS.

More info on HPA, and pre-HPA technology in IBM whitepaper:
http://www-3.ibm.com/pc/support/site.wss/MIGR-46023.html

[Albrecht Mühlenschulte (a7p)]

Is anyone able to check if this problem still exists in Edgy Eft (my "rescue partition" was among the first thinks that got removed from my Thinkpad). If there's no one able to confirm that this very specific problem still exists, I will close the bug within a month from today.

[Albrecht Mühlenschulte (a7p)]

No futher information given in a long time -> Bug considered closed. If anyone encounters this problem in currently supported versions of Ubuntu, please feel free to reopen it.