‘Upgraded’ to Windows 10 on Dual Boot, and Can’t Boot to Ubuntu Partition!

#ubuntu

bootdual-bootgrub2partitioning

I recently updated my windows 7 to 10, and destroyed grub in the process. I ran Boot-Repair on a live CD and managed to get the Windows Partition back. However grub still doesn’t come up for me.

The boot-repair url I received was http://paste.ubuntu.com/12189762/.

Edit:

Oldfred helped me figure out the problem. I didn’t really understand how the partition worked. The extended partition wraps around both the linux and swap partition, but for some reason the linux partition was not showing up. I booted to a live disk and ran parted rescue:

sudo parted /dev/sda unit s print //this printed the current partition table

sudo parted
unit s
rescue
Start? //Here I entered in 1 sector after the extended partition
End? //Here I entered in 1 sector before the swap parition

After that I ran boot-repair again and was able to restore grub back in place! Everything is working great now. Hopefully this post can help someone else!

Best Answer

It is not grub that is missing, but your Linux partition.

 /dev/sda2 208,894 416,761,855 416,552,962 5 Extended
 /dev/sda5 400,158,720 416,761,855 16,603,136 82 Linux
 swap / Solaris

You have a missing partition one or two sectors after the start of the extended and a few sectors before the start of sda5 swap. It probalby was sda5, and swap was sda6 but since using UUID to boot does not matter. Many use testdisk or parted rescue and reinstall grub to MBR and system works.

Backup partition table before any changes, so you can get back to current if changes not correct