[vox-tech] Kernel Panic

[Peter Jay Salzman]

On Thu 23 Dec 04,  5:17 PM, Robert G. Scofield <rscofield at afes.com> said:
>
> Grub gives me these options:
> 
> 1)  SuSE Linux 9.2
> 2) Windows
> 3) Floppy
> 4) SuSE Linux 9.2 (Failsafe)
> 5)  Memory Test
> 
> Options (1) and (4) lead to the same kernel panic error message I 
> mentioned earlier.
> 
> Option (3) won't help as I haven't made a boot floppy yet.
> 
> The SuSE installation CD gives me an option for an automatic repair.  
> But that doesn't work.
> 
> The SuSE installation CD give me a "rescue" option.  When I log in I get 
> a prompt.  But there's not much I can do with the prompt.  I can't find 
> anything.  There seems to be a massive root directory with nothing 
> there.  My notes on mounting don't have anything on mounting 
> partitions.  For example this doesn't work  "mount /dev/hdb2"
> 
> I'd at least like to get to my home directory and read a file I have 
> that contains my old mount points for each partition.  But I'm not going 
> anywhere with the rescue prompt.
> 
> Also, Rod Roark has a duplicate of the original install.  But GRUB does 
> not recognize it.  In other words, I have my "working" system, and a 
> duplicate install on /dev/hdb2 and /dev/hdb3, but I'm not sure which is 
> which.  I could figure it out if I could read that file in my home 
> directory.  But then I don't know enough about GRUB to figure out how to 
> add the duplicate to the boot menu.  One of my projects was to read  
> SuSE help about GRUB configuration, but I didn't get around to it in 
> time.

Hi Bob,

BTW, I keep a small notebook by the side of my computer that I write down
important stuff on.  For example:

   * Each hard drive partition and it's mount point, so I know where my
      root partition is.

   * A sketch of my SCSI cards, with notes indicating which port is
      what so I don't have to grub around looking at my Adaptec manuals.

   * Installed hardware including what drivers are needed for that
      hardware.

   * Anything that people like Mark, Rod, ME, Henry or Micah say.  :)

   * etc

Nothing sucks more than trying to rescue a system and not knowing what
partitions are what.

First order of business is to figure out where your partitions are.  I'm
assumming you have some kind of rescue disk.  The ones I find most useful
are Knoppix, Tom's floppy, LNX-BBC, and Timo.  Each have their upsides and
downsides.  For example, LNX-BBC was the most convenient, but for the
longest time didn't include ext3 (DUH!!!!!!).  Tom's is no-nonsense.  Timo
is also very good, but I wish he'd put the root password in his motd.  :)
I find the ones that automatically mount the partitions are cool, but not my
cup of tea.

Anyhow, here's how to get a map of your system.  Boot a rescue disk, and as
Rod mentioned, try this:

# mount /dev/hda1 /mnt
# ls -F /mnt
# umount /mnt

# mount /dev/hda2 /mnt
# ls -F /mnt
# umount /mnt

# mount /dev/hda3 /mnt
# ls -F /mnt
# umount /mnt

...

# mount /dev/hdb1 /mnt
# ls -F /mnt
# umount /mnt

# mount /dev/hdb2 /mnt
# ls -F /mnt
# umount /mnt

...


The cycle goes:

   1. Mount the next partition to /mnt
   2. Do an "ls -F" on /mnt
   3. Figure out what the partition is
   4. Write down what you learn.

So for example, let's say you do:

   # mount /dev/hdb3 /mnt
   # ls /mnt

and you see:

   autofs/   cache/  lib/    lock/  lost+found/  run/    state/  www/
   backups/  games/  local/  log/   mail/        spool/  tmp/

Then you know you found your /var filesystem ("log" and "lock" are the
tell-tale sign).  So in your notebook, you'd write:

   /dev/hdb3 is /var  Primary slave, 3rd partition

Don't worry about any partition you can't mount because of "wrong filesystem
type".  It's probably swap, an extended partition or something else
unimportant for now.

Keep going through your primary master:

   hda1, hda2, hda3, hda4, hda5  (prolly safe to stop at 5th partition)

and primary slave:

   hdb1, hdb2, hdb3, hdb4, hdb5  (prolly safe to stop at 5th partition)

You'll find your root partition and home partition for sure this way.


Once you find your root partition, you'll have access to /etc/fstab, which
should have all the info you need.   And you'll find your home partition
which contains all your personal notes.


What I want to know, and which has been alluded to in this thread but not
explicitly said, is "where the heck are your other kernels"?  I seriously
doubt Suse installed a new kernel and blew away your previous one.  It just
wouldn't make a drop of sense.

To find out what the heck is going on with your other kernels, use the above
process to find your /boot directory.  It'll either be on its own partition,
usually /dev/hda1 or /dev/hdb1, or it'll be under your root filesystem.

Try this out, and when you find /boot, can you post what you see in that
directory?

Pete

-- 
The mathematics of physics has become ever more abstract, rather than more
complicated.  The mind of God appears to be abstract but not complicated.
He also appears to like group theory.  --  Tony Zee's "Fearful Symmetry"

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