Arch Linux

pied04

Member

Registered: 2011-05-20

Posts: 21

Windows updates corrupt bootloader

I'm dual booting Arch Linux with Windows 10 on a laptop with UEFI.

Some windows updates result in linux becoming unbootable. It still has an entry in the boot menu, but when I select it I get the error 'vmlinuz-linux not found'.

When I boot from usb and mount my linux partitions, I find that `/boot/vmlinuz-linux` does exist, but `fsck.vfat` finds a problem with the file. After it attempts repairs, I get a new error ('vmlinuz-linux: unsupported'), but I still cannot boot linux.

My current solution to this problem is to boot from usb, `arch-chroot` into my linux partition, and `pacman -S linux` to reinstall the bootloader.

Has anyone experienced similar problems dual-booting windows 10? Is there a more permanent solution to this problem?

Scimmia

Fellow

Registered: 2012-09-01

Posts: 11,544

Re: Windows updates corrupt bootloader

Is fast boot turned off? I don't think that should affect the ESP, but good to check.

pied04

Member

Registered: 2011-05-20

Posts: 21

Re: Windows updates corrupt bootloader

Yes, I turned off Fast Startup the previous time this happened (about a month ago)

olive

Member

From: Belgium

Registered: 2008-06-22

Posts: 1,490

Re: Windows updates corrupt bootloader

I have a working dual boot with Windows 10 and don't have this problem. However I have (besides the Windows files) only refind in the ESP, and it fetch the kernel from my usual root partition. I leave the ESP unmounted in Linux. But you should be more precise. What bootloader do you use?  What fsck.vfat exactly says? How exactly have you run it?

basica

Member

From: Australia

Registered: 2012-10-31

Posts: 217

Re: Windows updates corrupt bootloader

FWIW I also dual boot on my desktop with Windows 10 using UEFI with no issues on Arch. I do need to reset the time in Windows whenever I boot into it for some reason, but since I use it only occasionally it doesn't really bother me enough to investigate why.

olive

Member

From: Belgium

Registered: 2008-06-22

Posts: 1,490

Re: Windows updates corrupt bootloader

FWIW I also dual boot on my desktop with Windows 10 using UEFI with no issues on Arch. I do need to reset the time in Windows whenever I boot into it for some reason, but since I use it only occasionally it doesn't really bother me enough to investigate why.

That may be because Windows interpret the Bios/UEFI clock as local time and Linux as UTC. You can configure Windows to interpret it as UTC to match Linux. Open regedit, navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation

and create a new DWORD key named RealTimeIsUniversal with a value of 1

Last edited by olive (2016-10-24 07:26:38)

basica

Member

From: Australia

Registered: 2012-10-31

Posts: 217

Re: Windows updates corrupt bootloader

That may be because Windows interpret the Bios/UEFI clock as local time and Linux as UTC. You can configure Windows to interpret it as UTC to match Linux. Open regedit, navigate to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\TimeZoneInformation

and create a new DWORD key named RealTimeIsUniversal with a value of 1

Thanks for the info. I'll check that out next time I'm logged into Windows.

Anyways, back to the OT.

Head_on_a_Stick

Member

From: London

Registered: 2014-02-20

Posts: 7,732

Website

Re: Windows updates corrupt bootloader

Is there a more permanent solution to this problem?

The FAT filesystem required for the ESP is notoriously fragile so perhaps you could try mounting just /boot/efi to the ESP rather than /boot

GRUB can be used to boot a non-ESP-located kernel image or you could try https://wiki.archlinux.org/index.php/EF … unt_Points

---

Are you infected with Wetiko?

pied04

Member

Registered: 2011-05-20

Posts: 21

Re: Windows updates corrupt bootloader

What bootloader do you use?  What fsck.vfat exactly says? How exactly have you run it?

I'm using grub. From memory, fsck.vfat reports an unexpected byte in vmlinuz-linux, and it says "assuming EOF" when it goes to fix the file.

I ran fsck.vfat after booting from usb, mounting my partitions and finding that the boot partition was mounted read-only because of errors. The sequence would have been something like:

# mount /dev/sda5 /mnt
# mount /dev/sda1 /mnt/boot
# arch-chroot /mnt
# ... try to reinstall kernel using pacman, errors about /mnt/boot being a read-only filesystem ...
# fsck.vfat /dev/sda1
# pacman -S linux

The idea of storing the kernel away from the EFI partition is interesting; I will look into switching to refind.

pied04

Member

Registered: 2011-05-20

Posts: 21

Re: Windows updates corrupt bootloader

perhaps you could try mounting just /boot/efi to the ESP rather than /boot

Thanks I'm looking into this now.

olive

Member

From: Belgium

Registered: 2008-06-22

Posts: 1,490

Re: Windows updates corrupt bootloader

# mount /dev/sda5 /mnt
# mount /dev/sda1 /mnt/boot
# arch-chroot /mnt
# ... try to reinstall kernel using pacman, errors about /mnt/boot being a read-only filesystem ...
# fsck.vfat /dev/sda1
# pacman -S linux

The idea of storing the kernel away from the EFI partition is interesting; I will look into switching to refind.

You are running fsck on a mounted filesystem. You should never do that and expect severe file system corruption if you do it. Always unmount any filesystem before fsck them.

pied04

Member

Registered: 2011-05-20

Posts: 21

Re: Windows updates corrupt bootloader

You are running fsck on a mounted filesystem. You should never do that and expect severe file system corruption if you do it. Always unmount any filesystem before fsck them.

Thanks, I'll keep this in mind for next time.