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Yesterday I've let windows 10 update but on restart grub was showing "unknown filesystem". After trying all solutions I've found on the web for that issue, I've used Ubuntu Live to fix that and now only Windows boot shows.

Having experienced similar problems before, I used Ubuntu live usb once again and for hours tried desperately to restore Ubuntu. I've tried all solutions I've found on the internet and moved no further...

Here are the coordinates of the issue:

fdisk -l

 Disk /dev/sda: 223.6 GiB, 240057409536 bytes, 468862128 sectors Units:
 sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512
 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes
 Disklabel type: dos Disk identifier: 0x76936d13


 Device     Boot     Start       End   Sectors  Size Id Type /dev/sda1 
 *         2048    206847    204800  100M  7 HPFS/NTFS/exFAT /dev/sda2          206848 385979729 385772882  184G  7 HPFS/NTFS/exFAT /dev/sda3      
 385980416 386936831    956416  467M 27 Hidden NTFS WinRE /dev/sda4    
 386940926 468860927  81920002 39.1G  5 Extended /dev/sda5      
 460462080 468860927   8398848    4G 82 Linux swap / Solaris

grub-install /dev/sda4

 Installing for i386-pc platform. grub-install: error: failed to get
 canonical path of `/cow'.

mount /dev/sda4 /mnt

 mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sda4,
 missing codepage or helper program, or other error.

testdisk

 Disk /dev/sda - 240 GB / 223 GiB - CHS 29185 255 63
      Partition               Start        End    Size in sectors  
 * HPFS - NTFS              0  32 33    12 223 19     204800  
 P HPFS - NTFS             12 223 20 24026  43 17  385773568  
 P HPFS - NTFS     24026  43 18 24085 179 30     956416
 L Linux                24085 211 63 28662  79 25   73521152  
 L Linux Swap           28662 111 58 29185  61 60    8398848

If I'm trying to set Linux partition as primary bootable it says "Structure bad".

How can I make my ubuntu work once again or at least recover my projects from that linux partition?

stumblebee
  • 3,547
Lucian Gabriel Popescu
  • 11
  • Duplicate of these. Windows updates partition table and does not include your logical Linux partition. You can use parted rescue or testdisk from Ubuntu live installer. http://askubuntu.com/questions/654386/windows-10-upgrade-lead-into-grub-rescue/655080#655080 & https://askubuntu.com/questions/944371/grub-and-ubuntu-disappeared-after-windows-update Your sda4 is the extended partition, Your missing partition should be inside it. – oldfred May 15 '18 at 19:03
  • @olfred Unfortunately none of the fixes suggested worked. – Lucian Gabriel Popescu May 18 '18 at 18:39
  • You cannot, nor should not make your Linux partition primary bootable. Windows must the the bootable partition (*). And Linux does not care if primary or logical. You may also need repairs using fsck. Try these commands on your LInux partition. https://askubuntu.com/questions/642504/ubuntu-14-04-is-not-booting-normaly-after-a-manual-hard-boot/642789#642789 – oldfred May 18 '18 at 19:05
  • Still didn't work: e2fsck: Attempt to read block from filesystem resulted in short read while trying to open /dev/sda4 Could this be a zero-length partition? – Lucian Gabriel Popescu May 19 '18 at 04:31
  • Your fdisk shows extended starting at 386940926, and swap starting at 460462080 or large gap. Your testdisk shows the Linux partition in that gap, did you not select to save that? You do not install grub to a partition, only to a drive like sda. And /cow means you were trying to install grub to installer /cow is copy on write or the installer. – oldfred May 19 '18 at 14:52

0 Answers0