[solved] no /dev/disk/by-uuid on boot

Message

kos · Post by **kos** » Sat Aug 15, 2020 1:24 am

Hi

My system stopped propagating `/dev/disk/by-uuid` on boot, and so root volume can't be found. The only thing I see in the rescue shell is `/dev/disk/by-id`.
`by-uuid` gets created later, when udev starts I guess.

I'm building my kernel using `genkernel --disklabel all`

What am I missing?

thanks

Whissi · Post by **Whissi** » Sat Aug 15, 2020 5:46 pm

Which genkernel version are you using? Because you mentioned udev I assume genkernel-4.1.0?

Root will be detected after udev started so this shouldn't be a problem.

Check that only one root kernel command-line argument is present and that this value is correct. Also, please tell us the exact error you are facing.

kos · Post by **kos** » Sat Aug 15, 2020 11:01 pm

I'm using genkernel 4.0.10, latest stable. Should I unmask and try 4.1.0?
By some reason my current version tries to mount root before starting udev I think. Visually there's much fewer logging happening before it tries to mount root, compared to what I was getting when it was working fine.

/proc/cmdline:

Code: Select all

root=/dev/ram0 real_root=/dev/disk/by-uuid/e71d81da-0885-4f7b-a45e-77d4533df813 rootfstype=ext4 real_init=/sbin/init keymap=us root_trim=yes fbcon=font:TER16x32 mitigations=off crashkernel=512M nokaslr BOOT_IMAGE=/boot/vmlinuz-5.8.0-gentoo-r1-x86_64 root=/dev/nvme0n1p2 ro intel_iommu=igfx_off

second `root=/dev/nvme0n1p2` got added because I specified it manually at boot after it fail to find `real_root`.
Will tell the exact error message after next reboot, but it was a standard message about not being able to find `/dev/disk/by-uuid/e71d81da-0885-4f7b-a45e-77d4533df813` with a prompt to specify the alternative or drop to rescue shell

Whissi · Post by **Whissi** » Sun Aug 16, 2020 12:32 am

4.1.0 was marked stable a few hours ago. Just wait, sync and test in a few hours.

By some reason my current version tries to mount root before starting udev I think.

This is confusing me. (E)UDEV is the new feature of genkernel-4.1.0 -- previous versions are using MDEV.

kos · Post by **kos** » Mon Aug 17, 2020 5:02 pm

re mdev vs udev -- I might be mixing them up, I don't know what genkernel is using internally.
But anyways, 4.1.0 solved the issue. Thanks!