UEFI is a strange beast to me but recently bought myself a new laptop, a Lenovo Y50-70. After getting dual-boot working fine for a few days, Debian disappeared from the EFI boot menu and grub no longer booted. This looks like an issue with a corrupt EFI partition. This is how i fixed it.
This caused me a major headache when i first setup my laptop, I wasnt aware this could cause a problem. After quite a lot of messing around and a lot of googling, this is what i came up with. This was a known issue.
It is possible the windows “Fast boot” setting has caused this. It is advisable to disable that. The option for that is in power options in Windows 8.
- Boot laptop using Debian disk.
- Select advanced recovery
- Mount the Debian partition and start the shell on that partition.
- Mount your EFI parttion.
NOTE: Mine was /dev/sda2
root@jon-debian-laptop:~# mkdir /mnt/sda2
Now we run dosfsck until no error appear. I had to run it several times.
root@jon-debian-laptop:~# dosfsck -r /dev/sda2
(Repeat multiple times, until you get the following)</p>
root@jon-debian-laptop:~# dosfsck -r /dev/sda2 Dosfsck 3.0.13, 30 Jun 2012, FAT32, LFN /dev/sda2: 325 files, 12146/65536 clusters root@jon-debian-laptop:~#
After that, i reinstalled Grub. That may not be needed, but i did so anyway.
Here are the instructions: Here