Arch Linux

Cheeto

Member

Registered: 2022-09-11

Posts: 64

Re: [SOLVED] Best way to recover from "failed to mount /boot"?

You're missing the point.
Your most recent effort to install the kernel failed because you passed an invalid package list.

We can speculatze all day long what errors existed on your previous attempts (i could not read anything at least in the beginning of the video), but we know what right now was your most recent flub.
Irobn that out to hopefully return to a working systen.

I think I misunderstood you. I thought you were saying that doesn't explain anything and to get back to trying to vfat module. I'll try to install the linux-zen-headers again.

Cheeto

Member

Registered: 2022-09-11

Posts: 64

Re: [SOLVED] Best way to recover from "failed to mount /boot"?

FIXED
I fixed the linux-zen-headers typo and and then installed linux-zen, and I'm back in the regular (non-snapshot) system that was restored from the earlier snapshot.
Thank you everyone immensely for your help, but before we shut the thread down can we recap please, for me and all the newbs who will see this in the future? The immediate problem is addressed but what should be learned from this? I don't mean like "haha you fucked up, don't fuck up lmao", I mean what's the takeaway in terms of btrfs, linux, and what tools did we learn from this that we can apply to future breakages, as well as to help avoid future breakages?

Here's what I'm gathering:

- It's not clear why this happened. Are all old snapshots useless every time a kernel is upgraded? Like someone else said in a similar thread, I'm pretty sure I've booted into old snapshots before, did I just manage to never do it after having upgraded a kernel? Does that mean all old snapshots are useless any time a kernel was upgraded, unless you restore > chroot in > upgrade the system > and possibly manually install headers and the kernel?
- Why did I have to manually install the headers? And even the kernel? I had already done pacman -Syu multiple times, and at least one of them upgraded the kernel.
- I'm understanding chrooting better. Mount the root subvolume to /mnt, mount the boot partition to /mnt/boot, then you can use the iso to manage a system that would otherwise not let you in. And, the subvol option was required.
- I'm not understanding btrfs any more. The issue with being unable to unmount the home subvolume with every variation of the path that I could think of, including variations of the relative path, has left me worried that everything I think I know about how to mount and unmount stuff with btrfs is fake. To this day, I've only managed to unmount the home subvolume by its ID or by commenting it out of the fstab.

Last edited by Cheeto (2023-05-23 16:56:29)

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 72,048

Re: [SOLVED] Best way to recover from "failed to mount /boot"?

It's not clear why this happened. Are all old snapshots useless every time a kernel is upgraded?

Your older snapshots might restore an older kernel that does not fit the one on the vfat /boot partition.
When this happens you need to install the older kernels and initramfs as well.
Running

/usr/share/libalpm/scripts/mkinitcpio install

as root *might* do, but essentially your entire restore-partial-snapshots approach is flawed. The kernel versions in /boot and /lib/modules *have* to align.

Why did I have to manually install the headers?

You didn't and I don't see anyone suggesting that. Just when you did, you flubbed that and that lead to pacman yelling an error at you instead of installing the kernel.

The issue with being unable to unmount the home subvolume with every variation of the path that I could think of

I don't think that was nor should be discussed in this thread.
You can open a new one, showing what you did and why and how it failed and ask for advice.

Or of course you could ask ChatGPT…

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How to upload text · How to boot w/o GUI · Disable Windows Fast-Start! · Fix your xinitrc

Cheeto

Member

Registered: 2022-09-11

Posts: 64

Re: [SOLVED] Best way to recover from "failed to mount /boot"?

Got it! Thanks again!!!