F9 doesn't find swap or /root system on new motherboard

[Craig White]

On Sat, 2009-01-17 at 23:58 +0100, M. Fioretti wrote:
> On Sat, January 17, 2009 11:35 pm, M. Fioretti wrote:
> > Greetings,
> >
> > My motherboard, on which I was running F9 x86_64 off one SATA drive, died.
> > I bought a new motherboard with a new cpu of the same type (AMD) and
> > connected the hard disk with F9 to it. Now Grub does start with these
> > options:
> >
> > kernel/vmlinuz/-2.6.27-etc ro root=/dev/sda3 rhgb mem=2048M enforcing 0
> >
> > but the process stops at a certain point
> 
> 
> after posting, I discovered the Grub geometry command. If I type in the
> grub CLI "geometry (hd" and then TAB, I get:
> 
> Possible partitions are:
> 
> Partition num: 0, Filesystem type is ext2fs, partition type 0x83
> 
> ditto for "Partition num" 2,4,5
> 
> Partition num 1 is listed as "Filesystem type unknown, partition type 0x82"
> 
> Now there are three things here I don't understand:
> 
> first, all my partitions where ext3, not 2. Can this be due to the fact
> that the motherboard died without fixing the journaling table, or whatever
> it is?
> 
> also, the second partition is just my swap, see also the type. Why,
> however, isn't the filesystem recognized? Should I reformat it? How, if I
> can't run a live cd or usb pen in this computer?
> 
> Last, why are the partitions labeled as hdN, when they where sdaN?
> 
> So, can I make Linux start in any way from that drive, in order to fix the
> system with proper tools, change grub.conf, etc..?
----
grub geometry is about physical hard drives identified in a numerical
order...hd0, hd1, hd2...

grub knows nothing about kernel modules like the scsi module which would
identify hard drives as sda, sdb... or ata modules that would identify
them as hda, hdb...

ext2 and ext3 are essentially the same and grub knows enough to be able
to read from them so it's not surprising that an ext3 partition looks
like an ext2 partition to grub.

there's no reason for grub to know anything about a swap partition -
that is identified, mounted and used by a kernel

lastly, if you successfully loaded the kernel from /boot partition, it
should first mount your / filesystem as read-only and if it senses any
issues, it should offer to repair it. Since you are not being offered a
chance to repair - your options now are quite limited.

You will need some other method to boot the computer (CD/DVD/USB
disk/key) in order to try to repair your /dev/sda3 which is your /
filesystem.

Personally, I would spare those efforts, get another hard drive
connected and copy off everything in /home (/dev/sda5 as you listed it)
and just wipe the hard drive and reinstall as it suggests that you have
larger issues on that hard drive.

Craig