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Comment by yaantc | Hacker News Reader

After several Win10 upgrades nuked grub on a dual boot system, I have found a much simpler process. Create a rEFInd [1] USB boot key once and for all. Then whenever grub is hosed, boot on this key: rEFInd will find the Debian partition and allows to run it directly. Then once in Debian just do an "update-grub" to fix things.

[1] https://www.rodsbooks.com/refind/getting.html

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You could just install rEFInd and make it the default bootloader with its auto find mode enabled.

win10 install nukes it sometimes as well. its a PITA

Have you found a way to deal with this? Swear I have refind on the non-Windows disk, but Windows updates sometimes replaces either the partition, or the default boot device. Mega frustrating!

https://wiki.archlinux.org/index.php/Unified_Extensible_Firm...

Over two years of dual booting with Windows 8 I never had it screw up my UEFI boot. The MBR I had tried in the past never lasted but with UEFI it just left everything on the ESP alone.

Like boomboomsubban, I have never had this happen. My current laptop shipped with Windows 8 and has had Windows 10 installed since the weekend after the public beta was released. It's also had an Ubuntu dual boot since exactly the same time. rEFInd was installed a few months later when I discovered it was still a thing (I had been a rEFIt user on Macs years ago).

Never once has the Linux boot manager/loader (either the original GRUB or rEFInd) been broken, by a Windows update or otherwise.

Windows of course has been well documented to happily overwrite any MBR bootloaders when you install it, but even that doesn't happen in a UEFI environment. Windows, rEFInd, GRUB, and whatever else you may have installed all have their own folders. It might change the default, but restoring your own choice is literally a matter of copying a single file.

EFI has plenty of problems of its own, but this is one it solved pretty well.

I've seen it do it as well and I'm pretty sure now that it's part of the "automatic repair" process that Windows does when it detects 3 (?) failed boots. What happened pretty often to me is that I'd miss the boot screen and Windows would start booting (it's the default bc it's a shared PC) and in order to not waste time, I'd force a reboot. After a few times, next time Win would actually boot, it would go into rescue mode and start poking around the EFI partition and efivars doing god knows what that ended up in my GRUB not even showing up in the F11 boot menu.

I've had this happen too, but I think it just changed something in the efivars, grub itself was still there and still operational, even though it didn't show up in the available boot options.

The workaround for me was the "boot from file" boot option, where I would be able to walk the directories in the efi partition and start grub. Once this was done, it was back in the boot option list.

Yeah, I've only had it remove the actual files once, when I had to use the recovery USB thing to fix a broken update. Unfortunately, my motherboard is from the very early days of UEFI and doesn't allow me to select files or even manage keys so I have to keep a microSD card with a bunch of bootloaders handy in case this happens (I still haven't gotten around to learning UEFI shell in order to manually boot).

Windows repair likes doing it.

I've had it nuke my bootloader a few times when I used to sill dualboot (now full Linux).

One time the windows installer confused the encrypted LVM disk with a corrupted NTFS partition (because it had an NTFS partition on it at some point and underlying data wasn't wiped properly) and tried to fix it. Suffice to say, that required a back restore, so now all my encrypted disks have a 100MiB NTFS buffer partition for Windows repair to fuck around it (until I removed dualboot, I occassionally found remnants of an attempted repair in them)

Is it sufficient to install Windows to a completely separate disk instead of a separate partition to prevent this? I can't imagine Windows starting to overwrite partitions or boot sectors on a drive it is not even installed to

I always install Windows to a different disk, so yes, Windows will try to recover partitions on other disks, especially when it finds multiple ESPs and the windows one isn't the active one (upon which it sometimes tries to install it's bootloader there, looks if that disk has the windows partition on it and confirms that yes, windows is installed on that disk because it has a windows-like ESP that it just installed, so it goes for a repair)

https://wiki.archlinux.org/index.php/Unified_Extensible_Firm...

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