[RESOLVED] Help-kernel panic! I didn't do it!!!!

[ziggy]

This morning when I booted I got a kernel panic.  Tried several times with the same result.  I'm currently running from the live CD (PCLinux2010).  Usually this kind of thing happens after I've been tinkering with things I know nothing about.  But this time it came out of the clear blue.  Yesterday I shut down a perfectly good operating system and today it's broke.  At least it didn't boot me into a terminal where there would have been operator panic instead of kernel panic.  I'm going to attach a picture (as in photograph) of the final screen output.  Basically it looks like it can't mount the root partition sdb8.  sdb5 is Linux swap, sdb9 is /home.

My system is an old Dell, P4, 2.2GHz, 1.5G ram, 2 internal HD's, WinXP on primary, PCLinuxOS 2010.1 on the secondary drive.  Not sure which kernel I'm running, but the system was up to date as of yesterday.  I've still got PCLos 2007/2009 installed and can boot into it ok, but it won't mount ext4 partitions.  Running from the 2010 live CD in PCCC - Manage Disk Partitions, I can see the root partition and it lists it as Type: Linux native (0x83).  Also, no volume label or UUID is shown and it won't give me the option to mount it.  It was formatted as ext4 when I installed.  In searching the forums I found this somewhat similar post http://www.pclinuxos.com/forum/index.php/topic,75302.0.html related to the fstab file.  However, I'm not able to get at my fstab since I can't mount the root partition.

Am wondering if anyone knows of any way to recover that partition or if I'm going to have to start from scratch again and download GB of updates.  I'm not very Linux savvy, so please keep it simple.  I have this sinking feeling in the pit of my stomach.

Any help is appreciated - ziggy

[Wildman]

It seems maybe your tinkering may have tinked your system good! Some one who know more than I should be along to help you shortly. 
 

[Joble]

The first thing I would try is an fsck -f of the / partition, from the liveCD.

[caf4926]

It might be helpful (seeing you are running from the Live CD
To see the result of

Code: [Select]

cat /etc/fstab

Code: [Select]

cat /boot/grub/menu.lst

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fdisk -l

[critter]

ziggy

you may have a problem with your /boot/grub/menu.lst file not knowing where to boot from.

I don't think that pclos 2007/2009 can recognize ext4 partitions so maybe your grub setup is trying to boot from an unrecognized file system?

Post the contents of your /boot/grub/menu.lst file plus the output from

Code: [Select]

fdisk -l              (as root)

This will help people to analyze your problem.

old polack is the best on this stuff so do a forum search for his answers or wait until he or somebody else comes along to help.

I would be surprised if you have lost any data as long as you haven't panicked and done something rash.

Post again if you still have a problem but please do not despair. Sometimes help comes from different time zones and sleep/work patterns can cause a day or so delay.

[ziggy]

Thanks for the replies.

joble
How do I do that?  Is the following correct?         fsck -f /dev/sdb8
Also, what does the -f option do?  I cheched the man page for fsck and couldn't find the -f option.  There is a -r option to repair.

caf4926
The output of the commands you suggested follows.  Doesn't appear that it found much info.

[guest@localhost guest]$ cat /etc/fstab
/dev/root / rootfs defaults 0 0
none /proc proc defaults 0 0
none /dev/pts devpts defaults 0 0

[guest@localhost guest]$ cat /boot/grub/menu.lst
cat: /boot/grub/menu.lst: No such file or directory

[guest@localhost guest]$ fdisk -l /dev/sdb8

Disk /dev/sdb8: 10.7 GB, 10742183424 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000

     Device Boot      Start         End      Blocks   Id  System
[guest@localhost guest]$

[Joble]

How do I do that?  Is the following correct?         fsck -f /dev/sdb8

Looks right to me, that's what I did the last time I used it.  Really? -f isn't mentioned in the man page?  Weird.  -r will ask for confirmation for every fix and can be quite tedious, -f is supposed to fix errors without confirmation, I believe.  Also the partition should be unmounted when you run it, else weird things can happen.

[ziggy]

OK.  Here's a more verbose output from fdisk -l.  I did as critter suggested and ran as root.  I don't think I can access my menu.lst file since I can't seem to mount the root partition.  By the way, I'm very nervous in front of this black-eyed terminal staring me in the face.
ziggy

[root@localhost root]# fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0xe4651a0a

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1           4       32098+  de  Dell Utility
/dev/sda2   *           5        9732    78140160    7  HPFS/NTFS

Disk /dev/sdb: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x82c78c0d

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1         392     3148708+   7  HPFS/NTFS
/dev/sdb2             393       14593   114069532+   5  Extended
/dev/sdb3   *         785        2090    10490445    c  W95 FAT32 (LBA)
/dev/sdb5             393         784     3148708+  82  Linux swap / Solaris
/dev/sdb6            2091        3396    10490413+  83  Linux
/dev/sdb7            3397        4702    10490413+  83  Linux
/dev/sdb8            4703        6008    10490413+  83  Linux
/dev/sdb9            6009        7313    10482381   83  Linux
/dev/sdb10           7314       14593    58476568+   7  HPFS/NTFS

Disk /dev/sdc: 1000 MB, 1000341504 bytes
16 heads, 32 sectors/track, 3816 cylinders
Units = cylinders of 512 * 512 = 262144 bytes
Disk identifier: 0x8e1265c0

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1        3816      976880    e  W95 FAT16 (LBA)
[root@localhost root]#

[kjpetrie]

Joble is right. From the livecd, open a terminal and type

Code: [Select]


su

Enter the root password (root on a standard livecd)

Code: [Select]


fsck -f /dev/sdb8

Wait for it to finish and give the default answer to any questions. Then reboot into your normal system and see whether it works.

[ziggy]

Thanks for all the help.  I was able from a root terminal to mount the offending partition sdb8 using the command mount -t ext4 /dev/sdb8 /mnt/sdb8.  So I can now attach my menu.lst and fstab files for your perusal before I do anything rash.  PCCC shows the partition as a blank rectangle and does not give me the option to mount it.  All the other partitions show up with their volume label and size in the corresponding  rectangle.  Anyway, maybe somebody with more knowledge than I can see if there's something awry in these files.
Thanks,  ziggy

[genomega]

From the looks of your table you may want to wait for o-p to weigh in.

[Old-Polack]

It might be helpful (seeing you are running from the Live CD
To see the result of

Code: [Select]

cat /etc/fstab

Code: [Select]

cat /boot/grub/menu.lst

Code: [Select]

fdisk -l

The first two will only show those items relative to the liveCD, not the installed system, so are useless.

[Old-Polack]

Thanks for all the help.  I was able from a root terminal to mount the offending partition sdb8 using the command mount -t ext4 /dev/sdb8 /mnt/sdb8.  So I can now attach my menu.lst and fstab files for your perusal before I do anything rash.  PCCC shows the partition as a blank rectangle and does not give me the option to mount it.  All the other partitions show up with their volume label and size in the corresponding  rectangle.  Anyway, maybe somebody with more knowledge than I can see if there's something awry in these files.
Thanks,  ziggy

What's on the 1 gb USB stick, and why is it in the USB port? Was it there when the kernel panicked? If you remove it, will your system then boot?

[Joble]

O-P!

* Joble wipes beads of sweat from his brow.

[ziggy]

Thanks for the response old-polack.  Nothing exotic on the USB stick.  It's become somewhat of a permanent attachment on this computer.  Mostly miscellaneous stuff like password manager and some date etc.  It's never given me any problem before.  Anyway, I removed it, rebooted, and got the same results.  I normally have several external firewire drives connected also, but these are not attached now.  I don't speak Linux very well and any problems I have are almost always self-inflicted, but this one is strange.  This is why I proclaimed innocence in my posting title.  Perhaps my next step is to run fsck as joble suggested?
ziggy