Need help with incorrectly nested partitions

[Svante Signell]

On Fri, 2010-08-20 at 11:30 +0200, Vladimir 'φ-coder/phcoder' Serbinenko
wrote:
> On 08/20/2010 10:34 AM, Svante Signell wrote:
> > Installing a new grub version gives the following output:
> > Setting up grub-pc (1.98+20100804-3) ...
> > Installing new version of config
> > file /etc/kernel/postinst.d/zz-update-grub ...
> > Installing new version of config
> > file /etc/kernel/postrm.d/zz-update-grub ...
> > grub-probe: warn: Discarding improperly nested partition
> > (hd1,msdos3,msdos1).
> > ...
> > Found Windows NT/2000/XP on /dev/sda1
> > ...
> > /usr/sbin/grub-probe: warn: Discarding improperly nested partition
> > (hd1,msdos3,msdos1).
> > Found Microsoft Windows XP Home Edition on /dev/sda2
> > /usr/sbin/grub-probe: warn: Discarding improperly nested partition
> > (hd1,msdos3,msdos1).
> > ...
> >
> >
>    
> It's only a warning and if you're not supposed to have subpartitions at
> all then you can just ignore them

What do you mean with subpartitions? I assume that /dev/sda1 is msdos1
(vfat) and /dev/sda2 is msdos3 (ntfs) and the warning says that they are
overlapping? The first partition /dev/sda1 is not of large interest, it
is the backup part of Windows at /dev/sda2. I don't need sda1 as I don't
plan to restore the original installation but sda2 is important. Anyway,
it is very annoying to get this message every tim grub-pc is updated! 

> > When booting and checking the partitions:
> > dosfsck 3.0.9, 31 Jan 2010, FAT32, LFN
> > There are differences between boot sector and its backup.
> > Differences: (offset:original/backup)
> >   65:00/01
> >   Not automatically fixing this.
> > /dev/sda1: 9309 files, 802467/945032 clusters
> > done.
> >
> >   
> man dosfsck

Yes as written below this would be the solution. But do I need to
rewrite the mbr, an if so I have forgotten how to do that, install-mbr
or something else related to grub without destroying anything?

> > /etc/fstab entries:
> > # /dev/sda1     /winrescue   vfat    defaults,noauto  0       2
> > UUID=693D-1E3B  /winrescue   vfat    defaults,noauto  0       2
> > # /dev/sda2            /winxp ntfs  defaults,noauto,user,umask=0022 0 2
> > UUID=F0FC6717FC66D77E /winxp  ntfs  defaults,noauto,user,umask=0022 0 2
> >
> > The backup offset problem could be solved by:
> > http://www.linuxquestions.org/questions/linux-software-2/utterly-fascinating-boot-sector-problem-differences-offset-original-backup-40214/
> > umount /dev/sda1
> > fsck.vfat -ar /dev/sda1
> > and then re-write the mbr (how to do that??)
> >
> > Appreciate any help you can give. It would be nice to solve these
> > problems without needing to scrap the whole Windows partitions. I cannot
> > reinstall, since reinstalling Windows would erase all GNU/Linux stuff I
> > have installed on other partitions on that fisk (and this is the most
> > important!)
> >
> > As I'm not subscribed, please Cc: me then replying.
> > Thanks,
> > Svante Signell
> >