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I had windows and ubuntu installed in dual booting for the last three years and everything was going well until today. Usually the screen would come up for me to choose whether to go to ubuntu or windows.

However today I encountered GNU GRUB "Minimal BASH-like editing is supported". I started by looking through my partitions and could only access one (others are "unknown filesystem). In there I have two folders: efi/ and boot/, but nothing else. I was able to find the grub.cfg file but nowhere vmlinuz, linux-3.2.0-14*, etc.

Thus I could not do anything that https://help.ubuntu.com/community/Grub2/Troubleshooting suggests. I was able to get into my windows and tried to access my linux files using DiskInternals Linux Reader, but it did not let me open those partitions. I tried live booting from a usb, and reinstalling, which did not work either (just a black screen after choosing those options).

My last try was using boot-repair disk, which booted and repaired, but rebooting my computer I still end up at the same GRUB screen (so the problem was not repaired). I would be very thankful for any further advice!

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  • You may have a badly damaged Linux filesystem. Please post the URL that Boot Repair gave you. Without that detailed information, any answer is going to be guesswork.
    – Rod Smith
    Feb 23, 2016 at 14:44
  • Thanks so much for your reply! My boot repair URLs were: paste.ubuntu.com/15171127 and paste.ubuntu.com/15171173 (I tried it twice). Feb 24, 2016 at 16:32

1 Answer 1

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My initial guess seems to be correct. Your partition table suggests that Ubuntu is installed to /dev/sda6; that's the only Linux data partition:

Partition    Start Sector    End Sector  # of Sectors System
/dev/sda1           2,048     2,050,047     2,048,000 Windows Recovery Environment (Windows)
/dev/sda2       2,050,048     2,582,527       532,480 EFI System partition
/dev/sda3       2,582,528     2,844,671       262,144 Microsoft Reserved Partition (Windows)
/dev/sda4       2,844,672   699,840,511   696,995,840 Data partition (Windows/Linux)
/dev/sda5     945,602,560   976,773,119    31,170,560 Windows Recovery Environment (Windows)
/dev/sda6     699,840,512   924,450,815   224,610,304 Data partition (Linux)
/dev/sda7     924,450,816   940,075,007    15,624,192 Swap partition (Linux)

Unfortunately, Boot Repair can't figure out what filesystem /dev/sda6 contains:

sda6: __________________________________________________________________________

    File system:       
    Boot sector type:  Unknown
    Boot sector info: 
    Mounting failed:   mount: unknown filesystem type ''
mount: unknown filesystem type ''

This is Very Bad. It's possible that running fsck on /dev/sda6 will fix the problem; however, that could make matters worse, too. As a safety measure, you might want to do a low-level backup of it before you do anything else, as in:

sudo dd if=/dev/sda6 of=/path/to/lots/of/space/sda6.img

That way, if you try a repair and it doesn't work, you'll at least be able to restore the backup. Note that you must have a disk with lots of free space on it, and you'd point the of= option to store the backup in a file there. By "lots of free space," I mean at least as much space as the partition you're backing up, or 107.11 GiB.

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  • Thank you very much Rod! I have most of my data saved externally so I tried entering fsck /dev/sda6 in grub mode. I get "cant find command fsck'." Feb 25, 2016 at 11:51
  • If by "grub mode" you mean the grub> prompt, that won't work. The grub> prompt indicates that GRUB is in charge of the computer. This is before Linux or any of its utilities are available. You must boot a live image, like the one you used to run Boot Repair, in order to run fsck. Also, you'll need to run it with sudo, as in sudo fsck /dev/sda6.
    – Rod Smith
    Feb 25, 2016 at 13:40
  • Thanks! unfortunately I don't seem to be able to boot ubuntu from a live usb. Boot repair was the only thing that worked. Feb 25, 2016 at 13:50
  • Whatever you used to run Boot Repair should be able to run fsck, too. That said, I'm not familiar with any Boot Repair-specific boot disk. If it launches straight into Boot Repair, you may need to find a way to bypass that. Hitting Ctrl+Alt+F1 (or some other function key) might get you to a text-mode shell you could use.
    – Rod Smith
    Feb 25, 2016 at 14:00

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