About a week ago Windows 10 ran its automatic updates and after that I'm unable to boot to ubuntu the way I was doing it (pressing f12 and manually selecting Ubuntu partition). Now it takes me to a black screen saying Unknown Filesystem grub rescue when I try to access it that way.
The partition isn't wiped out and Ubuntu works just fine, but I have to enter a few commands as shown in this video(Non-English) to access it.
Would anyone mind helping me to "revert" whatever windows did so I can keep booting to ubuntu manually when I want to with f12 key?
Additional info – I asked this question on Reddit and I was asked
"what is the output of 'fdisk -l' in the terminal?"
This is what shows up:
Disk /dev/sda: 465,8 GiB, 500107862016 bytes, 976773168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 7DCE2DB6-E1A6-4A44-9EC2-96460D5449EB
Device Start End Sectors Size Type
/dev/sda1 2048 923647 921600 450M Windows recovery environment
/dev/sda2 923648 1128447 204800 100M EFI System
/dev/sda3 1128448 1161215 32768 16M Microsoft reserved
/dev/sda4 1161216 244113228 242952013 115,9G Microsoft basic data
/dev/sda5 244113408 245759999 1646592 804M Windows recovery environment
/dev/sda6 245762048 830351359 584589312 278,8G Microsoft basic data
/dev/sda7 830351360 838543359 8192000 3,9G Microsoft basic data
/dev/sda8 838543360 976773119 138229760 65,9G Linux filesystem
Thank you very much in advance 🙂
[1]: https://www.youtube.com/watch?v=NMMdNke-gkY
Best Answer
In theory, a Windows update should not have affected GRUB's ability to load its configuration file, which is what appears to have happened. I have two ideas about what has happened, and fixing one of them might correct the problem:
grub.cfg
file on the ESP. If so, disabling these features might fix the problem. I therefore recommend you start by doing precisely this. See this page for information on disabling Fast Startup and this one for information on disabling Hibernate.I recommend you look into Fast Startup and Hibernate first. If disabling those features doesn't help, then you'll have to look into more radical solutions. These include, in order of radicalness:
sudo update-grub
in a Terminal window in Ubuntu.sudo grub-install
will re-install the main GRUB EFI binary, which might fix the problem if it's the source of the problem.grub-install
, but if the problem lies in a narrow range of issues beyond whatgrub-install
can handle, Boot Repair might do the trick.I recommend starting with updating your GRUB configuration file and moving to more radical solutions later, on the off chance that something drastic (Boot Repair, in particular) could cause serious problems. rEFInd run from a USB flash drive or CD-R is unlikely to create new problems because it changes nothing on your disk when run in this way; only if you install it on your hard disk will it make any permanent changes.