Re: [gentoo-user] Beta test Gentoo with mdev instead of udev; version 5

[Daddy]

On March 11, 2012 at 10:17 AM Alan McKinnon <alan.mckinnon@×××××.com>
wrote:

> On Sun, 11 Mar 2012 07:27:05 -0400 (EDT)
> Daddy <daddy@×××××××××××××××××××××.com> wrote:
>
> > On March 11, 2012 at 5:09 AM Walter Dnes <waltdnes@××××××××.org>
> > wrote:
> >
> > >   This revision makes 2 changes...
> > >
> > > A) The removal of udev is now standard instead of optional.
> > > udev-181 and higher will be pulling in kmod, and anything else that
> > > kmod depends on.  Removing udev will avoid unnecessary cruft on
> > > your machine.
> > >
> > > B) Splitting up step 3) into 3a) and 3b) for greater clarity as
> > > requested in user feedback.
> > >
> > >   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 a) Create /sbin/linuxrc containing 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.  Remember to
> > > "chmod 744 /sbin/linuxrc" to make it executable.
> > >
> > >  In the bootloader "append" line, include "init=/sbin/linuxrc".  If
> > > you're using lilo remember to re-run lilo to implement the
> > > changes.  If you're using another bootloader, make the equivalant
> > > initialization.
> > >
> > >
> > > 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) Remove udev as per the following instructions...
> > >
> > > * 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
> > >
> > > --
> > > Walter Dnes <waltdnes@××××××××.org>
> > >
> >
> > Having personally long considered Lennart Poettering a 'spawn of the
> > devil' my question is ... is this your reaction to systemd?
>
>
> No, it's his reaction to the fantastical amount of kitchen-sinking
> going on surrounding udev. Most specifically, it's the recent
> "requirement" foisted on the udev-using community to require
> either /usr to be part of / or to use an initramfs.
>
> Walter simply wants to show that mdev is a suitable replacement for
> udev in simple environments eg embedded, simple desktops without
> complex hotplug requirements, and servers.
>
> Canek will no doubt chip in about how this is the way things are going,
> it is inevitable, the boot sequence is becoming complex and various
> other rehashings of what's coming out of udev upstream.
>
> However, something needs to be pointed out in that regard. What udev
> upstream is saying is probably quite true, but only within the limits
> of the environment in which they work and udev is designed to handle -
> sophisticated desktops. The three cases I mentioned are perfectly valid
> use-cases, comprise a large percentage of the Linux installed base,
> should be catered to and have no need of the sophistication current
> udev aims to provide.
>
> As such, mdev is a good fit and we can add Walter to the long list of
> people before him who selflessly worked to make our software work
> better.
>
> >
> > One minor typo to point out:
> >
> > /atc/portage/package.mask should be /etc/portage/package.mask
> >
> > I just joined this list last week, but might consider sacrificing some
> > hardware to join your endeavor if you need more testers.
>
>
> Welcome to the list, you'll soon get to know all the personalities
> here. We have at least one of everything - class clowns, old farts,
> newbies, voices of reason, influential devs and even the occasional
> fellow who knows what he's talking about.
>
> :-)
>
>
>
>
> --
> Alan McKinnnon
> alan.mckinnon@×××××.com


First, my class is old fart. Though I'm always in IRC, mailing lists and
forums are more my speed.

<story>

I built my first PC in 1984, but dropped out of society in totality from
1986 until 1996. In '97 an old PC was given me, then in '98 we bought a
bare bones desktop box online and applied some nasty Mickey$oft OS to it.
Subsequent hardware failures led me down the path I'm on today.

In 1999 a Linux geek where I worked introduced me to RedHat, which couldn't
be successfully updated on my dialup connection. To me at that time, it
looked like some hobby kit you'd get from Radio Shack.

In 2003, while living in China, one of the principles of the privacy
service we used out of Virginia convinced me my computer was fast enough,
and rather than making a RAID0 with the second drive, to "try Linux". It
was RedHat 9.0, and after one month the distro itself sickened me.

However, in that length of time I'd found "cdrecord" and various other apps
and scripts via CLI ... and seen the ability of Linux to multitask ... and
I was hooked. The next few months were spent on Debian, with a kind
gentleman from Belgium offering to mentor me. But all he offered, it turned
out, were his scripts to do things. One day he just disappeared off the
face of the earth.

By that time I'd gotten addicted to rebuilding my kernel, especially
getting it down to < 1.0MB. And since this guy's "script" was the only way
I'd done it, me and Google struck out for the bright, new Linux horizon.
Someone had pointed me to "The Cathedral and The Bazaar", also, and my mind
was made up. The business model and practices of Mickey$oft and that
fruitloop company had opened my eyes to a world I wished I'd never seen, so
I was looking for a way out. (They'd stolen, and killed by lawsuit, two
particular projects of interest to me.)

After a month of reading (primarily some Google groups and
LinuxQuestions.org), it seemed that my desires would best be met by (a)
LFS, (b) Gentoo, or (c) Slackware. Not wanting to spend so much time
compiling from source, not knowing the benefit, and having Gentoo buddies
who regularly broke their system and spent more time compiling than I spent
awake -- Slackware became my Linux distro. From Nov 2003 until the end of
2010, I was a Slacker.

Eventually the Slackware community no longer appealed to me (nicest thing I
can say). Most of my time working on projects was spent with the #2 in
Slackware via email and IM anyway.

In January 2011 we moved from China back to America. The other big change
was my migration to Gentoo.

Today we have 1 workstation, 1 server, one PC, and 2 laptops running Gentoo
(all but one laptop have no other OS). No devices plugged into our LAN are
automounted.

My server is headless and X-less; all the other comps run Fluxbox. IMO
there is no need for a desktop environment, but then, we use our computers
for work. When we want to play we leave them alone.

We opened Happy Penguin Computers 5 months after returning to America, and
are still getting established. That's my introduction to this list.

</story>

We have spare parts so tomorrow I'll build a test machine. My Gentoo
knowledge is quite limited, seeing as how we moved back after 9 years and
had to start life over. But I can start by following this guide, and
probably reading and learning about ebuilds. They're quite different from
Slackware's build scripts, primarily due to dependency checking, etc.

Kindest regards,
Bruce Hill