Linux – Cannot start archlinux after update: Cannot find uuid

arch linuxbootkernelkernel-modules

I updated archlinux with "pacman -Syu" and then when I've restart, the system can't start. This is the report:

Warning: /lib/modules/4.11.9-1-ARCH/modules.devname not found - ignoring
version 232
Error: device 'UUID=b5a9a977-e9a7-4d3d-96a9-dcf9c3a9010d' not found. Skipping fsck.
Error: can't find UUID=b5a9a977-e9a7-4d3d-96a9-dcf9c3a9010d 
You are now being dropped into a emergency shell.
Can't access tty: job control turned off

In that shell my keyboard doesn't work.

I'm trying with a livecd of archlinux: mounting the partitions and using chroot.
I check the uuid of the root partition in "/etc/fstab". It's my fstab:

# /dev/sda2 UUID=b5a9a977-e9a7-4d3d-96a9-dcf8c3a9010d   /           ext4        rw,relatime,data=ordered    0 1  
# /dev/sda1 UUID=FBA9-977B          /boot       vfat        rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro 0 2  
# /dev/sda4 UUID=a43b8426-c93a-4f32-99c8-9dd5cf645373   /home       ext4        rw,relatime,data=ordered    0 2  
# /dev/sda3 UUID=9eec735e-3157-4e0e-a5c6-ef3a7c674201   none        swap        defaults    0

And it's the result of "lsblk -f"

NAME   FSTYPE   LABEL       UUID                                 MOUNTPOINT
loop0  squashfs                                                  /run/archiso/sfs/airootfs
sda                                                              
├─sda1 vfat                 FBA9-977B                            
├─sda2 ext4                 b5a9a977-e9a7-4d3d-96a9-dcf8c3a9010d /mnt
├─sda3 swap                 9eec735e-3157-4e0e-a5c6-ef3a7c674201 
└─sda4 ext4                 a43b8426-c93a-4f32-99c8-9dd5cf645373 /mnt/home

I've updated the system again with "pacman -Syu" and I tried to make "mkinitcpio -p linux", but it haven't solved the problem (in spite of the result of the command it's ok). This is the report:

==> Building image from preset: /etc/mkinitcpio.d/linux.preset: 'default'
  -> -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux.img
==> Starting build: 4.11.9-1-ARCH
  -> Running build hook: [base]
  -> Running build hook: [udev]
  -> Running build hook: [block]
  -> Running build hook: [block]
WARNING: Possubly missing firmware for module: aic94xx
WARNING: Possubly missing firmware for module: wd719x
  -> Running build hook: [autodetect]
  -> Running build hook: [modconf]
  -> Running build hook: [filesystems]
  -> Running build hook: [keyboard]
  -> Running build hook: [fsck]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-linux.img
==> Image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux.preset: 'fallback'
  -> -k /boot/vmlinuz-linux -c /etc/mkinitcpio.conf -g /boot/initramfs-linux-fallback.img -S autodetect
==> Starting build: 4.11.9-1-ARCH
  -> Running build hook: [base]
  -> Running build hook: [udev]
  -> Running build hook: [block]
WARNING: Possubly missing firmware for module: aic94xx
WARNING: Possubly missing firmware for module: wd719x
  -> Running build hook: [modconf]
  -> Running build hook: [filesystems]
  -> Running build hook: [keyboard]
  -> Running build hook: [fsck]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-linux-fallback.img
==> Image generation successful

I tried to change the order of HOOKS in "/etc/mkinitcpio.conf". But it doesn't work. This is the current order:

base udev block autodetect modconf filesystems keyboard fsck

"uname -r" returns:

4.11.7-1-ARCH

"pacman -Q linux" returns:

linux 4.11.9-1

The file of warrning "/lib/modules/4.11.9-1-ARCH/modules.devnam" exists.

I tried to install and use "linux-lts" but the result it's the same.
I use grub and I tried to reconfigure it too.

What can I do?

Best Answer

I just forgot mount boot (thank you, jasonwryan).

The solution to this problem, in my case was:

Use a livecd to mount all partitions and use chroot.
Update:

pacman -Syu
Regenerate initramfs using:

mkinitcpio -p linux
If you use grub:

grub-mkconfig -o /mnt/boot/grub/grub.cfg
Restart.

Related Solutions

ERROR: Root device mounted successfully, but /sbin/init does not exist

As @Leiaz very correctly pointed out in the comments, /sbin in Arch (and by extension, Manjaro) is now a symlink to /usr/bin. This means that unless /usr is mounted, /usr/sbin/init will not exist. You therefore need to make sure that /usr is mounted by the initial ramdisk. That's what the Arch wiki quote in your OP means:

If you keep /usr as a separate partition, you must adhere to the following requirements:

Enable mkinitcpio-generate-shutdown-ramfs.service or add the shutdown hook.

Add the fsck hook, mark /usr with a passno of 0 in /etc/fstab. While recommended for everyone, it is mandatory if you want your /usr partition to be fsck'ed at boot-up. Without this hook, /usr will never be fsck'd.

Add the usr hook. This will mount the /usr partition after root is mounted. Prior to 0.9.0, mounting of /usr would be automatic if it was found in the real root's /etc/fstab.

So, you need to generate a new init file with the right hooks¹. These are added by changing the HOOKS="" line in /etc/mkinitcpio.conf. So

Boot into Mint and mount the Manjaro / directory:
```
mkdir manjaro_root && sudo mount /dev/sda11 manjaro_root
```
Now, Manjaro's root will be mounted at ~/manjaro_root.
Edit the mkinitcpio.conf file using your favorite editor (I'm using nano as an example, no more):
```
sudo nano ~/manjaro_root/etc/mkinitcpio.conf
```
Find the HOOKS line and make sure it contains the relevant hooks
```
HOOKS="shutdown usr fsck"
```
Important" : do not remove any of the hooks already present. Just add the above to those there. For example, the final result might look like
```
HOOKS="base udev autodetect sata filesystems shutdown usr fsck"
```
Mark /usr with a passno of 0 in /etc/fstab. To do this, open manjaro_root/etc/fstab and find the /usr line. For this example, I will assume it is /dev/sda12 but use whichever one it is on your system. The "pass" number is the last field of an /etc/fstab entry. So, you need to make sure the line looks like
```
/dev/sda12  /usr  ext4  rw,errors=remount-ro     0      0
                                                        ^
                         This is the important one -----|
```
Create the new init image. To do this, you will have to mount Manjaro's /usr directory as well.
```
sudo mount /dev/sda12 ~/manjaro_root/usr
```
I don't have much experience with Arch so this might not bee needed (you might be able to run mkinitcpio without a chroot) but to be on the safe side, set up a chroot environment:
```
sudo mount --bind /dev ~/manjaro_root/dev && 
sudo mount --bind /dev/pts ~/manjaro_root/dev/pts && 
sudo mount --bind /proc ~/manjaro_root/proc && 
sudo mount --bind /sys ~/manjaro_root/sys &&
sudo chroot ~/manjaro_root
```
You will now be in a chroot environment that thinks that ~/manjaro_root/ is actually /. You can now go ahead and generate your new init image
```
mkinitcpio -p linux
```
Exit the chroot
```
exit
```
Update your grub.cfg (again, this might not actually be needed):
```
sudo update-grub
```

Now reboot and try booting into Manjaro again.

¹ "Hooks" are small scripts that tell mkinitcpio what should be added to the init image it generates.

Unable to Find Root Device in Arch Linux – Boot Issue Fix

The problem appears to be that rEFInd isn't automatically creating the refind_linux.conf file in the /boot directory.

From step 4 of the "EFI Stub Loader Support Technical Details" from the rEFInd documentation:

rEFInd looks for a file called refind_linux.conf in the same directory as the kernel file. It consists of a series of lines, each of which consists of a label followed by a series of kernel options. The first line sets default options, and subsequent lines set options that are accessible from the main menu tag's submenu screen. If you installed rEFInd with the refind-install script, that script created a sample refind_linux.conf file, customized for your computer, in /boot. This file will work without changes on many installations, but you may need to tweak it for some.

I'm not sure why it isn't creating this file, but it's highly likely you can solve the problems you're having by creating it.

Creating the `refind_linux.conf` file

The Arch Linux wiki has an excellent entry on how to do this, but essentially you place it in the same directory as your kernel (usually in /boot, either by creating it automatically or manually). The first uncommented line of the file will be the default parameters for booting the kernel.

I created my file using the mkrlconf command, and the resulting file at /boot/refind_linux.conf looked like this:

"Boot with standard options"  "archisobaseddir=arch archisolabel=ARCH_201610"
"Boot to single user mode"    "archisobaseddir=arch archisolabel=ARCH_201610 single"
"Boot with minimal options"   "ro root=UUID=514a997c-a921-403d-849f-d901d26a73db"

We're getting somewhere, but this didn't work yet. Because I created it from the live USB, the first two entries are not correct as they refer to ISO on the USB instead. The final entry is actually correct though, and this is because like the error you received, it sets the root device from '' to the UUID of your / disk.

So to set it as the primary boot option just delete the other lines and change the label.

"Boot with standard options"  "ro root=UUID=514a997c-a921-403d-849f-d901d26a73db"

Save the file and restart the system, it should now work correctly!

Footnotes

This is of course a long way to go about creating the file. You don't have to use the mkrlconf to generate it, you could manually create it yourself. It's more that it auto-populates the disk UUID (which I do not want to have to copy and type out manually).
Step 5 from the Stub Loader Technical Details (linked above) outlines how, if no refind_linux.conf file is present, rEFInd will look for a kernel entry in /etc/fstab. With a weird volume configuration though it's unlikely this will work.