Tue Aug 28 17:08:52 EEST 2012
How to Repair Ubuntu Linux which failed due to computer switch off during update :)
My sister tried updating her Ubuntu to a newer version but in the middle of the dist-update process had to go out and hence closed her notebook thinking the update would continue. I'm not fully aware what happened next, maybe the battery of the notebook went, maybe the computer entered sleep mode in the middle of some important package update or whatever. The result at hand however was on next opening her Ubuntu powered Acer Aspire 5736Z stopped booting properly.The Ubuntu boot up occured in the middle of booting the BootSplash (from some of the /etc/init.d ... init scripts).
As a result the BootSplash status was failed and on the screen the GUI cursor appeared refreshing every few seconds, whether on every refresh the screen become blank, while the hard drive was reading on and on, continuously. Since the screen was keeping mostly blank I had no way to see exactly why the hard drive was scraping on and on....
My first guess was to try to boot the Ubuntu in single user mode (without GUI environment) and then complete the interrupted packages apt-get dist-upgrade.
In the old days of RedHat and probably nowdays in Fedora, I remember entering single user mode was easy just press I button few times on OS boot and the system would boot in non-interactive mode. The I (boot single-mode) shortcut however is not compatible with Deb based distros (as I found out by trying it out unsuccesfully).
Actually during booting process, this notebook did not even prompted the GRUB menu with even simple choice to choose an old kernel or something, hence I took a quick on the net how can I make the GRUB menu appear on Ubuntu!.
The reason why GRUB menu did not appear on the laptop boot was due to very short GRUB (select) boot timeout delay set.
Hence to make the GRUB prompt (select) prompt appear in Ubuntu it is necessery to:
1. Hold continously the SHIFT key at
boot
Once the textmode GRUB selection screen appears, as I read in instructions in blogs one has to:
HIT e key, over default boot-up kernel, e.g.:
Ubuntu, with Linux 3.2.0-23-generic
Now to boot Ubuntu in single user mode as I red it is necessery to modify near line:
linux /boot/vmlinuz-3.2.0-24-generic
root=UUID=bc6f8146-1523-46a6-8b\ 6a-64b819ccf2b7 ro quiet
splash
to something like:
linux /boot/vmlinuz-3.2.0-24-generic
root=UUID=bc6f8146-1523-46a6-8b\ 6a-64b819ccf2b7 ro single quiet
splash
initrd /boot/initrd.img-3.2.0-24-generic
Then finally to load up with the changed GRUB options, I've press Ctrl+X
Unfortunately this didn't work on my sister bugged Ubuntu. So i continued looking for way to boot without X server, I've found another blog recommending to change: quiet splash words with text in grub kernel load-up options ..
In my case none of the ways to boot without X or single user mode worked out so I finally decided to do it the "old-fashioned" classical way - by using Ubuntu Install CD, booting in "Try Ubuntu" mode and using the good old chroot cmd.
So fixing Ubuntu, came up to booting with Ubuntu Install CD with option: Try Ubuntu without any change of your computer, further on once the CD boot up, I entered console and inside console used commands similar to one of my previous posts - How to mount /proc, /dev and chroot in Linux
In other words fixing up the broken Ubuntu came to issuing :
# mkdir /mnt/recover
# chroot /dev/sda1 /mnt/recover
root@ubuntu:~# mount /proc
root@ubuntu:~# mount /proc/pts
root@ubuntu:~# mount -a
root@ubuntu:~# mount /dev
root@ubuntu:~# dpkg-reconfigure -a
root@ubuntu:~# apt-get update
....
root@ubuntu:~# apt-get --yes upgrade
....
root@ubuntu:~# apt-get --yes dist-upgrade
....
Onwards during the apt-get upgrade and apt-get dist-upgrade few questions poped up asking me if I would like to replace some files with their new versions on each questions I substituted the files with the new maintainer version. Then finally after PC restart my sis Ubuntu boot up fine with the latest Ubuntu version 12.04.