Accidentally deleted some kernal files

[ghormley]

Xubuntu 13.10 desktop .. while trying to gain space on boot partition to do daily updates, I accidently deleted the wrong kernal files. Now Grub only shows two options and they are both memtest86 optioms. I meant to delete all previous kermel files and did plus a bit more. I need to reinstall the kernal using a live CD but I don't know how. Can anyone help, please?

[ghormley]

Tried to follow the thread and command line options at
http://ubuntuforums.org/showthread.php?t=1034523
with no success. It fell apart after the xhost + line.

[deadflowr]

Do you really need the xhost setting?
Shouldn't that be for running graphical apps, like synaptic, which is what caljohnsmith was looking to try.

Otherwise maybe this, easy to understand approach
http://askubuntu.com/questions/28099/how-to-restore-a-system-after-accidentally-removing-all-kernels
might work.

[ghormley]

Forgot to add this in original post but the problem began with a failure of the chroot command.

Error response was: chroot: failed to run command '/bin/bash' : No such file or directory

Get the same error every time i perform the steps leading to the chroot command.

Thans for your assistance!

John

[ghormley]

Searching the Internet for the chroot error message led me to thisd post:

http://forum.linuxcareer.com/threads/1618-chroot-failed-to-run-command-bin-bash-No-such-file-or-directory

While I suspect there is a clue in it, it's still over my head.

Also, I've read that a symlink has changed in recent updates that my be the cause of this error. I read this statement:

/bin/bash is in the new location /usr/bin/bash (moved from /bin/bash by the
>> update) with with a proper symlink in /mnt/bin/bash pointing to ../usr/bin/bash

at this page:
https://mailman.archlinux.org/pipermail/arch-general/2013-March/033099.html

While it refers to Arch, is the situation the same or similar in Debian/Ubuntu environments?

Thanks for any guidance anyone can offer.
John

[steeldriver]

Which chroot steps are you following exactly? it sounds more likely that not all the bits of your target chroot filesystem got mounted properly

[ghormley]

Thanks, steeldriver. Here are the steps I am attempting after booting wiht a live CD (Xubuntu 13.10) and opening a terminal:

sudo mount /dev/sda1 /mnt

sudo mount --bind /dev /mnt/dev
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys

sudo chroot /mnt

This is where the error occurs.

apt-get install linux-image-generic

exit
sudo umount /mnt/sys
sudo umount /mnt/proc
sudo umount /mnt/dev
sudo umount /mnt

sudo reboot

Of course nothing else works unless the chroot works to change to the HDD as a focus for the kernal instasll.

These steps come from the page:
http://askubuntu.com/questions/28099/how-to-restore-a-system-after-accidentally-removing-all-kernels

Thanks,
John

[steeldriver]

Are you 100% sure /dev/sda1 contains your Ubuntu / (root) filesystem? what is the output of


sudo parted -l

or


sudo fdisk -l

What does


ls /mnt

say after the mount commands?

[ghormley]

xubuntu@xubuntu:~$ sudo parted -l
Model: ATA WDC WD10EALX-009 (scsi)
Disk /dev/sda: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 256MB 255MB primary ext2 boot
2 257MB 1000GB 1000GB extended
5 257MB 1000GB 1000GB logical lvm


Model: WD Elements 1023 (scsi)
Disk /dev/sdc: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 1000GB 1000GB primary ntfs boot


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/xubuntu-root: 997GB
Sector size (logical/physical): 512B/512B
Partition Table: loop

Number Start End Size File system Flags
1 0.00B 997GB 997GB ext4


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/xubuntu-swap_1: 3209MB
Sector size (logical/physical): 512B/512B
Partition Table: loop

Number Start End Size File system Flags
1 0.00B 3209MB 3209MB linux-swap(v1)

xubuntu@xubuntu:~$ ls /mnt
dev etc lost+found memtest86+_multiboot.bin root tmp
dsys grub memtest86+.bin.jcg proc sys
xubuntu@xubuntu:~$

======================

sdc was a bootable disk in another life but has never been reformatted and is not used as a bootable disk now.

Thanks,
John

[steeldriver]

OK so your root (/) is actually on a logical volume (LVM) and you have a separate /boot - so you're going to need to


mount /dev/mapper/xubuntu-root at /mnt
mount /dev/sda1 at /mnt/boot

and THEN do the bind mounts I think - after which the chroot *should* find everything (famous last words...)

[ghormley]

Thanks, steeldriver! That solved the problem and the system is booting once again with no apparent loss of data. I certainly do appreciate the help. You are a lifesaver!

John