# [SOLVED]after changing to udev some device files are missing

## thexder1

I was recently moving my old server running gentoo over to udev. I guess I did not reboot until today, and now one hard drive no longer has device files for it or the partitions, and the raid arrays that I was using do not have device files. based on the information I am seeing, it looks like the devices are there and working, but as the device files do not exist any real use, like mounting is not possible.

 I have checked sys and proc filesystems and they both seem to agree that everything is there and working. please help me get udev working properly, or help me move back off of udev as a last resort.Last edited by thexder1 on Thu Sep 26, 2013 5:57 pm; edited 1 time in total

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## NeddySeagoon

thexder1,

Welcome to Gentoo.

What /dev entries seem to be missing?

A few examples will do.

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## thexder1

the specific ones that I know are missing are:

/dev/sde

/dev/sde1

/dev/sde2

/dev/md0

/dev/md1

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## SamuliSuominen

Is CONFIG_DEVTMPFS=y enabled in the kernel? Is /dev mounted as devtmpfs?

 *Quote:*   

> 
> 
> $ zgrep DEVTMPFS /proc/config.gz 
> 
> CONFIG_DEVTMPFS=y
> ...

 

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## thexder1

Hello ssuominen,

Thanks for the help I did not have DEVTMPFS enabled in the kernel. I think I can get it to work from here. I will post again if I have problems that I cannot figure out.

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## thexder1

Well, I got stuck again. when trying to mount the devtmpfs I just get the message unknown filesystem type. Everything that I am seeing indicates that mount should know that filesystem type and be able to mount it without a problem.

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## SamuliSuominen

 *thexder1 wrote:*   

> Well, I got stuck again. when trying to mount the devtmpfs I just get the message unknown filesystem type. Everything that I am seeing indicates that mount should know that filesystem type and be able to mount it without a problem.

 

If the kernel has the required support then the '/etc/init.d/udev' init script will do the mounting for you during boot so there isn't any manual mounting involved here.

You can also enable CONFIG_DEVTMPFS_MOUNT=y which makes it even more safe, then the kernel will do the mounting itself.

And you can also enable CONFIG_IKCONFIG=y which makes /proc/config.gz available so you can check options from the currently running kernel using eg. `zgrep DEVTMPFS /proc/config.gz` since `grep DEVTMPFS /usr/src/linux/.config` doesn't guarantee it's the actual .config of the running kernel. It's easy to, for example, forget to mount /boot partition and then copy the kernel image to wrong directory because of it.

Or it's easy to forget to run `make clean` in /usr/src/linux before building it again.

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## thexder1

oops, I knew I forgot something. cleaning and compiling the kernel again. this time with CONFIG_IKCONFIG=y enabled.

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## thexder1

Thanks for the help, I just needed to do a make clean then re-build the kernel and everything is working now.

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