Re: [gentoo-user] Re: Beta test Gentoo with mdev instead of udev; version 4

[Pandu Poluan]

On Feb 18, 2012 6:46 AM, "Walter Dnes" <waltdnes@××××××××.org> wrote:
>
>  This revision removes a couple of steps in the process, so there's
> less stuff involved.  If only software developers worked that way <G>.
>
> * Busybox stable is now past the buggy version that didn't work with
> mdev.  There is no need to keyword version 1.19.2
>
> * The virtual/dev-manager-0.ebuild has been modified as per my feature
> request to support an mdev-based system.  There is no longer any need
> for a customized/hacked ebuild in an overlay
>
>  The usual warnings apply...
> * this is a beta
> * use a spare test machine
> * if you don't follow the instructions correctly, the result might be
>  an unbootable linux
> * even if you do follow instructions, the result might be an unbootable
>  linux
>
>
> 1) Set up your kernel to support and automount a devtmpfs filesystem at
>   /dev
>
> * If you prefer to edit .config directly, set
>  CONFIG_DEVTMPFS=y and CONFIG_DEVTMPFS_MOUNT=y
>
> * If you prefer "make menuconfig", the route is as shown below.  Note
>  that the "Autount devtmpfs..." option won't appear until you enable
>  "Maintain a devtmpf..." option.
>
> make menuconfig
>  Device Drivers  --->
>    Generic Driver Options  --->
>      [*] Maintain a devtmpfs filesystem to mount at /dev
>      [*]   Automount devtmpfs at /dev, after the kernel mounted the rootfs
>
>  Once you've made the changes, rebuild the kernel.
>
>
> 2) Set up for emerging busybox.  busybox requires the "mdev" flag in
> this situation.  The "static" flag is probably also a good idea.  In
> file /etc/portage/package.use add the line
>
> sys-apps/busybox static mdev
>
>   Now, "emerge busybox"
>
>
> 3) In the bootloader append line, include "init=/sbin/linuxrc" where
>   the file /sbin/linuxrc consists of *AT LEAST*...
>
> #!/bin/busybox ash
> mount -t proc proc /proc
> mount -t sysfs sysfs /sys
> exec /sbin/init
>
>   This should be enough for most users.  If you have an unusual setup,
>   you may need additional stuff in there.  If you're using lilo remember
>   to re-run lilo to implement the changes.
>
> 4) Remove udev from the services list, and replace it with mdev.  Type
>   the following 2 commands at the command line
> rc-update del udev sysinit
> rc-update add mdev sysinit
>
>
> 5) reboot to your new kernel.  You're now running without using udev.
>
>
> 6) ***THIS STEP IS OPTIONAL***  This is only to alay any suspicion that
>   udev is still in use.
>
> * execute the following command at the commandline
> emerge --unmerge sys-fs/udev
>
> * In file /atc/portage/package.mask, append the line
> sys-fs/udev
>  Create the file if it doesn't already exist.  You now have a totally
> udev-free machine
>

Thanks for the update!

I've been mdev-ing my servers, and no problems whatsoever until now (touch
wood!).

For those still on the sidelines re: mdev-for-udev, be aware that progress
is happening rapidly with regards to what udev feature is 'vital' for
modern systems.

Heck, mdev is already perfect for my needs: it can rename devices, fire up
a script on hotplug/hotunplug events, load a firmware if told so by the
kernel...

I suggest interested people should at least lurk in the busybox mailing
list. The mdev-for-udev discussion us quite fresh, patches (not bloats)
have been submitted... and we have our very own Walt Dnes in that list,
proudly waving the Gentoo banner ;-)

Rgds,