[SOLVED] Device /dev/disk/..... does not exist

f222 · n00b Joined: 15 Jul 2017 Posts: 5

Hi,

I had a working gentoo install with UEFI + systemd + encrypted disk.

Yesterday I modified the kernel so I could use docker and when I reboot my computer I just got a message :

"device /dev/disk/by-uuid/....... doesn't exist or access denied". I get into shell mode and the folder /dev/disk did not exists, and the command blkid doesn't show anything.

I boot on the gentoo install key, unencrypted my disk, chroot the sytem and modified the kernel to an older version and it didn't work either. I did this again to rebuild the initramfs and to update grub but nothing worked.

If anyone has an idea of what to do it would be great.

Thank you by advance

eccerr0r · Posted: Mon Jul 17, 2017 8:00 am Post subject:

How far in the boot are you getting?

Udev creates /dev/disk/*

If you're dying in initramfs, which initramfs are you using? On my personal initramfs, it uses mdev which I don't recall if it creates the /dev/disk/* links...

Is /dev/ populated ? Does /dev even exist?

Ensure you're running the kernel you think you're running using uname, perhaps the kernel you're using is missing devtmpfs or something?
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f222 · n00b Joined: 15 Jul 2017 Posts: 5

To be honest with you i'm new to gentoo (I was on archlinux before) and I don't really know how far I go, I see the message 'loading initial ramdisk' an then loading LVM groups, (with a warning failed to connect to lvmetad which I have from the beginning). if I keep pressing enter to force him to stop I got a kernel panic.
I just know that i am in busybox

/dev exists and is populated by loop, ram, tty....

I made my kernel and my initramfs using genkrnel-nex using the following command lines :

genkernel --luks --lvm --busybox --keymap --menuconfig kernel

genkernel --install --udev --lvm --noramdisk-modules initramfs

eccerr0r · Posted: Mon Jul 17, 2017 10:56 pm Post subject:

It sounds like you're still in initramfs (when you ls in that shell, is it your normal hard disk or seemingly something else? if it seems like something else, it's probably in initramfs. Also if it didn't say it's starting openrc then that's more evidence.) And it sounds like it's the gentoo genkernel initramfs (which unfortunately I know very little about.)

Do you recall anywhere that you specified /dev/disk/by-uuid/.... or was it something that the initramfs generated?

Are you using root=/dev/disk/by-uuid/.... for your boot loader? (This sort of doesn't work...) Then again, it shouldn't have suddenly stopped working.

Also make sure that you're using the correct initramfs for your kernel...

Have a picture of the failure screen somewhere?
_________________
Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?

NeddySeagoon · Posted: Tue Jul 18, 2017 8:08 am Post subject:

f222,

The initrd loads because "loading LVM groups" comes from LVM which is a user space tool loaded from the initrd.
The text of the panic message would be really useful. Just the Unable to mount root .... part, if thats what it is.

/dev/disk/.. and friends are created by udev and are not normally used for finding the root device.
Please pastebin your /boot/grub/grub.cfg

If the problem happens after root is mounted, using /dev/disk/.. in /etc/fstab is not longer encouraged.
Did you miss the news item 2016-11-04 Important fstab and localmount update ?

Its not clear yet what the panic is about. I assume that its mounting root but there are other causes too.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

f222 · n00b Joined: 15 Jul 2017 Posts: 5

Thank you for your answers.

Here is what you asked, the grub.cfg

I did not enter/dev/disk/... anywhere, I use the CRYPT_ROOT=UUID=... option in grub

here is the precise error message : https://image.noelshack.com/minis/2017/29/2/1500414148-img-20170718-233434.png

Thank you for your help

PS is there a way to cleanly redo all my kernel using genkernel (for example wipe everything I have done in config )

Zucca · Posted: Tue Jul 18, 2017 10:09 pm Post subject:

f222 · n00b Joined: 15 Jul 2017 Posts: 5

I might have made some advancement.
I took the default genkernel configuration and follow the wiki about systemd, xorg, laptop-mode, docker... to setup the kernel. And now the error message is not the same, I got an error telling me "/sbin/cryptsetup not found in initramfs"
Here is a screenshot of it : https://image.noelshack.com/minis/2017/29/3/1500495016-img-20170719-220137.png

This might be related to what @Zucca said but I can't find how to have cryptsetup inside initramfs.

I will continue to search and tell you I there is any update

NeddySeagoon · Posted: Wed Jul 19, 2017 10:40 pm Post subject:

f222,

There are several things missing there. The most telling line is

f222 · n00b Joined: 15 Jul 2017 Posts: 5

I finally found and understood all my mistakes. I am just a freaking idiot :oops:

The first problem I had was because I accidentally disabled something needed by dm-crypt.

with this thing disabled my computer didn't boot and I thought that maybe it could be caused by initramfs which had not been recompiled after the kernel, so I decided to recompile it and this is where I made my second mistake : I didn't send the good params to initramfs, id did :

NeddySeagoon · Posted: Thu Jul 20, 2017 8:25 pm Post subject:

f222,

You have learned from your errors. That's experience.
Its only stupid if you don't learn ... but my excuse is it must have been a 'senior moment' :)

You have also helped others but you may not realise it.
Others will find this thread in future and you posted a solution.

No apology is required.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

eohrnberger · Apprentice Joined: 09 Dec 2004 Posts: 240

Hi all.

The subject caught my eye in that I'm experiencing the same thing, that udev doesn't seem to be populating the /dev/disk tree of symlinks.

While this isn't fatal, my preference is to have my zpools using the /dev/disk/by-id links so that the HD's model and serial are always displayed (making tracking down issues much easier).

I've referenced the Gentoo wiki page, turned on udev debugging, rebooted and checked the log, but still, doesn't seem to be generating the info that makes the error more obvious.

What else can I check? What references exist for this issue?

eohrnberger · Apprentice Joined: 09 Dec 2004 Posts: 240

OK. Spotted the issue. When emerging eudev, saw this notice:

* Checking for suitable kernel configuration options...
* CONFIG_SYSFS_DEPRECATED: should not be set. But it is.
* CONFIG_SYSFS_DEPRECATED_V2: should not be set. But it is.
* Please check to make sure these options are set correctly.
* Failure to do so may cause unexpected problems.
* Determining the location of the kernel source code
* Found kernel source directory:

Fixed that and all's well.