Kernel update with /boot not mounted

Darillian · 2011-12-09 12:35:11

Hey guys,

I did an system update and also updated the kernel from 3.0 to 3.1.4. Unfortunately, I forgot about the "noauto" option for /boot in fstab, so when I reboot, obviously all modules started looking in the "old" directory, because I haven't updated the /boot partition, so wifi's down...
The problem is, that if I try to mount the partition, it says it does not know the filesystem type "ext2".

Did actually happen what I'm afraid of? The kernel updated, detected no ext2 drives since boot was umounted and therefore did not see any need for supporting an old filesystem type, then I rebooted and bascially threw the keys into the car and shut the doors?

Cheers
Darillian

Last edited by Darillian (2011-12-09 14:06:29)

graysky · 2011-12-09 12:38:28

No idea what you're talking about. That option shouldn't matter and the kernel knows which module directory is it using.

$ grep boot /etc/fstab
/dev/disk/by-uuid/0fc6ed20-0bce-4e26-860c-6e63dd3a35ea	/boot	ext3	defaults,relatime	0	1

What does your /etc/mkinitcpio.conf look like? That is where various hooks are defined to generate your kernel images.

Last edited by graysky (2011-12-09 12:40:29)

Darillian · 2011-12-09 12:52:46

In my mkinitcpio.conf I got the following hooks:
base udev autodetect pata scsi sata filesystems usbinput

I'm just wondering why I cant mount the ext2 formatted /boot partition, although before the update I could do it easily with the 3.0 kernel
The boot entry in fstab looks like this:
/dev/sda11 /boot ext2 noauto 0 1

patroclo7 · 2011-12-09 13:42:15

Well, since the /boot partition was not mounted at the time of the upgrade and your bootloader chooses the kernel from there, my guess is that when you reboot you are actually using the old kernel, which does not find the matching modules since they have been upgraded (they are not in /boot).
I would downgrade the kernel package to the old version (take it from your pacman cache), reboot, mount /boot (now the old modules should be loadable) and at this point upgrade again to the new kernel and reboot again.
P.S.: the first reboot could be unnecessary, but I assume that you are on a desktop machine, so that at least it doesn't hurt.

graysky · 2011-12-09 13:57:07

I agree with patroclo -- but why in the world would the OP have /boot unmounted? If so, he should have received a warning from linux.install:

  if grep "^[^#]*[[:space:]]/boot" etc/fstab 2>&1 >/dev/null; then
    if ! grep "[[:space:]]/boot" etc/mtab 2>&1 >/dev/null; then
      echo "WARNING: /boot appears to be a seperate partition but is not mounted."
      echo "         You probably just broke your system. Congratulations."
    fi
  fi

@op - type this:

grep Congratulations /var/log/pacman.log

Last edited by graysky (2011-12-09 13:57:57)

Darillian · 2011-12-09 14:04:45

Well, since I played around with the boot partition and crashed GRUB, I got impatient and simply reinstalled the whole thing...
So I don't know what the hell I've done, but chrooting from a LiveCD and trying to reinstall grub with pacman didnt help

As the error message puts it:

WARNING: /boot appears to be a seperate partition but is not mounted.
You probably just broke your system. Congratulations.

graysky · 2011-12-09 14:07:54

Dude, you need to keep your /boot mounted when you upgrade kernel. Further, I see no advantage to unmount it at all. Remove that noauto switch from your /etc/fstab to avoid this problem in the future. Reinstalls with Linux is RARELY needed by the way.

patroclo7 · 2011-12-09 15:28:00

Reinstall was really overkill in this case.

The practice of keeping /boot unmounted was anciently suggested to keep the kernel protected (from rm -rf / or similar kinds of autolesionism), but it does not make any real sense to me. If you destroy your OS there is not much utility in preserving the kernel only... Or perhaps it does make sense if in /boot there is also the kernel for another linux installation in the same machine, not sure.

Arch Linux

#1 2011-12-09 12:35:11

Kernel update with /boot not mounted

#2 2011-12-09 12:38:28

Re: Kernel update with /boot not mounted

#3 2011-12-09 12:52:46

Re: Kernel update with /boot not mounted

#4 2011-12-09 13:42:15

Re: Kernel update with /boot not mounted

#5 2011-12-09 13:57:07

Re: Kernel update with /boot not mounted

#6 2011-12-09 14:04:45

Re: Kernel update with /boot not mounted

#7 2011-12-09 14:07:54

Re: Kernel update with /boot not mounted

#8 2011-12-09 15:28:00

Re: Kernel update with /boot not mounted

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