# [SOLVED] kernel doesn't find partition /dev/sd*

## Fenixoid

Suddenly after reboot kernel does not find root partition /dev/sda2

It stops at boot and asks root password for maintense or hit CTRL+D for reboot. When I give root password, I can see all data in read-only mode, it shows no sd* devices in /dev/, everything's mounted on /dev/root

When booting in live-cd, I can fully access, mount all partitions, write, delete files and etc. Tryed reiserfschk --check, --fix-fixale /dev/sda2. Everything's normal with /dev/sda2, but when booting - it stops at above position.

Even deleted /dev/sda1, reformated, writed kernel again - but still no luck.

Any ideas how to fix this? Needs to be done very quickly :-/

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## richard.scott

downgrade your udev to about v149 rather than the 15x release.

Rich

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## idella4

Fenixoid;

  you'll need to gather some info to lead to pinning it down.  When it stops, you can login into the shell.  From there you'll need to obtaining the booting log to report the kernel's events, in /var/log/dmesg and or /var/log/messages if you have the sys logger emerged and activated.  If you can use the live cd you can collect it from that, and post the log data.

From the brief description it could be many faults

What happened to the system just before it stopped login.

If you can get it, post the emerge --info.  Got to start to describe the fault.

On logging in as root when it dtops, enter

mount -o remount,rw,exec rootfs /

and tell what effect it has, i.e. if the system becomes read write.

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## richard.scott

 *idella4 wrote:*   

> On logging in as root when it dtops, enter
> 
> mount -o remount,rw,exec rootfs /
> 
> and tell what effect it has, i.e. if the system becomes read write.

 

This won't help if he doesn't have any /dev/sd? devices to mount.

See this bug thread for others with the same problem:

https://bugs.gentoo.org/show_bug.cgi?id=329887

Downgrading udev is the only fix.

Rich.

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## Fenixoid

How come gaving udev  151-r4 on several up-to-date gentoo servers works fine (the same partition file systems), even when restarting several times, and this one some how got bad?

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## richard.scott

do you use baselayout-2? If so, this will be why it works for you and breaks for others.

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## jesnow

 *richard.scott wrote:*   

>  *idella4 wrote:*   On logging in as root when it dtops, enter
> 
> mount -o remount,rw,exec rootfs /
> 
> and tell what effect it has, i.e. if the system becomes read write. 
> ...

 

And it doesn't work! 

```

Armstrong jesnow # emerge -DNup world

These are the packages that would be merged, in order:

Calculating dependencies... done!

[ebuild     UD] sys-fs/udev-149 [160] USE="devfs-compat%*"

!!! Multiple package instances within a single package slot have been pulled

!!! into the dependency graph, resulting in a slot conflict:

sys-fs/udev:0

  ('ebuild', '/', 'sys-fs/udev-149', 'merge') pulled in by

    >=sys-fs/udev-124 required by ('installed', '/', 'sys-fs/cryptsetup-1.1.2', 'nomerge')

    >=sys-fs/udev-125 required by ('installed', '/', 'sys-apps/hal-0.5.14-r2', 'nomerge')

    virtual/dev-manager required by world

    (and 3 more)

  ('installed', '/', 'sys-fs/udev-160', 'nomerge') pulled in by

    >=sys-fs/udev-151-r2 required by ('installed', '/', 'sys-fs/lvm2-2.02.67-r2', 'nomerge')

    (and 6 more)

```

Looks like I would have to walk back half a dozen other packages in order to fix this issue. What is going on here? Why has udev suddenly decided not to populate /dev with the device files I need?

Cheers, 

Jon.

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## jesnow

It's not as bad as I thought, I only have to downgrade udev, lvm2 and cryptsetup to get back to udev-149, but it still begs the question: what is wrong with the current "stable" udev? Or what's wrong with my setup? I can't stay at udev-149 forever!

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## tenorism

I had the same problem with my server (stable amd64 arch) and when I used udev above 146-r1 it could not boot giving me the same unpleasant message.

After many chroots  decided to check migrating to baselayout-2 and everything is fixed. Now I use udev-151-r4.

[Edit]

Just found out that my /dev/sda1 (which is usually mount at /boot) is gone for permanent vacation or smt.

For now >sys-fs/udev-146-r1 in my /etc/portage/package.mask because its very hot and I don't like freaking out with these summer udev versions!!!

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## eccerr0r

I've found upgrading the kernel for the later udevs works... all my machines that borked with udev 151 were fine after upgrading to 2.6.34 (with deprecated sysfs stuff unset)....

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## krinn

https://forums.gentoo.org/viewtopic-p-6293727-highlight-udev.html#6293727

look at the date of this post, people can't just search the forum  :Smile: 

(i admit some issue & solve should be sticky more)

it's because of newer udev version with baselayout 1 & kernel with feature SYSFS_DEPRECATED(or v2) on

to my knowledge openrc users aren't affect, and newer kernel (2.6.34+) don't have SYSFS_DEPRECATED option, so nobody can select it.

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## tenorism

 *krinn wrote:*   

> 
> 
> it's because of newer udev version with baselayout 1 & kernel with feature SYSFS_DEPRECATED(or v2) on
> 
> to my knowledge openrc users aren't affect, and newer kernel (2.6.34+) don't have SYSFS_DEPRECATED option, so nobody can select it.

 

My problem is solved. You are right. I was using kernel-2.6.34-r1 with genkernel and SYSFS_DEPRECATED (and v2) were enabled in .config. I remember to have manually disable them but maybe I am starting to have Alzheimer's.

I then changed to a manual configuration (now that I found what kernel-config should be for Supermicro X7SPA-H) and SYSFS_DEPRECATED was disabled and my problem is gone. Colder weather already...

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