Repair and Resume the Ubuntu OS

I am running an Dell VOSTRO 1015 which is running dual-boot windows-7 and Ubuntu 12.10. (well, up until today). i forget to connect the charger for my laptop, and was working with same and due to the lack of charge its suddenly switched off. When i connected the charge and turned on my laptop and tried to boot  Ubuntu OS. The boot process drops to the busy box shell and i end up at the prompt:

BusyBox v1.18.5 (Ubuntu 1:1.18.5-1ubuntu4) built-in shell (ash) Enter 'help' for a list of built-in commands.


Like this…

I tried to resuming the Ubuntu OS but it didn’t happen. I’ve been researching others who have had this same problem, but haven’t been able to find any of those solutions to work for me. so finally I fount it seems that i have a bad super blocks. I followed the following steps to recover the same.

Follow this:

  • First, boot into a live CD or USB.
  • Find out your partition number by using this command.
sudo fdisk -l|grep Linux|grep -Ev 'swap'
  • Then, list all superblocks by using the command.
dumpe2fs /dev/sda10 | grep superblock

  • Replace sda10 to your drive number
  • You should get a similar output like this.
  Primary superblock at 0, Group descriptors at 1-6
  Backup superblock at 32768, Group descriptors at 32769-32774
  Backup superblock at 98304, Group descriptors at 98305-98310
  Backup superblock at 163840, Group descriptors at 163841-163846
  Backup superblock at 229376, Group descriptors at 229377-229382
  Backup superblock at 294912, Group descriptors at 294913-294918
  Backup superblock at 819200, Group descriptors at 819201-819206
  Backup superblock at 884736, Group descriptors at 884737-884742
  Backup superblock at 1605632, Group descriptors at 1605633-1605638
  Backup superblock at 2654208, Group descriptors at 2654209-2654214
  Backup superblock at 4096000, Group descriptors at 4096001-4096006
  Backup superblock at 7962624, Group descriptors at 7962625-7962630
  Backup superblock at 11239424, Group descriptors at 11239425-11239430
  Backup superblock at 20480000, Group descriptors at 20480001-20480006
  Backup superblock at 23887872, Group descriptors at 23887873-23887878

  • Choose an alternate superblock from this list, for this case alternate superblock # 32768
  • Now, to check and repair a Linux file system using alternate superblock # 32768:
fsck -b 32768 /dev/sda2
  • You should get similar output like this.
fsck 1.40.2 (12-Jul-2007)
e2fsck 1.40.2 (12-Jul-2007)
/dev/sda2 was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Free blocks count wrong for group #241 (32254, counted=32253).
Fix? yes
Free blocks count wrong for group #362 (32254, counted=32248).
Fix? yes
Free blocks count wrong for group #368 (32254, counted=27774).
Fix? yes
/dev/sda2: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sda2: 59586/30539776 files (0.6% non-contiguous), 3604682/61059048 blocks

  • Now try mounting the partition
mount /dev/sda2 /mnt
  • Now, try to browse the filesystem with the following commands
cd /mnt
mkdir test
ls -l
cp file /path/to/safe/location

If you’re able to perform the above command, you have most probably fixed your error.

Now, restart you computer and you should be able to boot normally..