Re: Apologies - WAS: Re: [gentoo-user] Systemd upower

[Rich Freeman <rich0@gentoo.org>]

On Sun, Jun 8, 2014 at 1:26 PM, Tanstaafl <tanstaafl@libertytrek.org> wrote:
>
> First question: is there a decent guide to installing a gentoo system from
> scratch using systemd as the init system?

I've done this a few times on VMs.  Just follow the handbook, but skip
steps about configuring hostname/timezone/locale/etc since systemd
does this (but do set up locale.gen).  Then follow the systemd install
guide.  If you follow both guides to completion you won't hurt
anything, but you'll just end up configuring some things twice (but
systemd does migrate some of your settings over).

>
> Second question: is there a decent guide to how to switch from OpenRC to
> systemd?

Yes, the systemd wiki page is the best place to go for this.  It is
pretty straightfoward.

The only thing I'd do differently is just use networkd.  The guide
doesn't include that yet.

cat > /etc/systemd/network/dhcp.network
[Match]
Name=en*

[Network]
DHCP=yes
--- end file ---

(as long as you keep the extension you can call that file whatever you
want, and if your interface doesn't match that glob you can tweak it)

Also, if you have any network filesystems be sure to set the _netdev
option in fstab.

>
> Third question: is there a decent guide on how to switch from systemd back
> to OpenRC, if I encounter any serious problems on a production box?

For the most part you can just change the init setting on your kernel
line to switch back and forth.  You'll end up using udev packaged with
systemd, but for the most part that shouldn't cause too many problems.
Oh, if you're using dracut there is a chance it won't realize you
aren't running systemd in your kernel and that could cause some issues
(I was getting some of that before I intended to cut over to systemd
in my last migration, but I didn't mess with it for long).

Just keep in mind that immediately following the migration you won't
have any services enabled.  That means no network, no sshd, etc.
Starting that stuff up is pretty easy, but it is just like having a
fresh OpenRC install.

Rich