Re: [gentoo-user] Systemd as drop-in replacement for udev?

["Canek Peláez Valdés" <caneko@gmail.com>]

On Fri, Dec 6, 2013 at 12:32 AM, J. Roeleveld <joost@antarean.org> wrote:
> On Fri, December 6, 2013 00:17, Canek Peláez Valdés wrote:
>> On Thu, Dec 5, 2013 at 4:26 PM, Róbert Čerňanský
>> <openhs@tightmail.com> wrote:
>>> I will try openrc-force as temporal solution until I'll find a new
>>> display manager and give heart breaking good by to GDM.
>>
>> You could *try* to run systemd and see if you like it.
>>
>> Many of us do.
>
> For the option to try systemd, I would first require a detailed how-to on
> how to switch back to OpenRC without requiring reverting to backups or
> doing a full reinstall.

You don't need to use backups, much less a full reinstall. However,
several packages must be reemerged and a couple ones must be
uninstalled before you switch to systemd. Obviously, you need to do
the opposite to revert back to OpenRC.

Which packages must be reemerged and which ones must be uninstalled
depends on what do you have installed. It is mostly handled by
portage, though, so you don't need to worry about it.

If you unpack a stage3 tarball for a new installation, the only thing
you need to do to get systemd is to "emerge systemd" and change your
init line in your boot loader. Portage will uninstall udev for you,
and OpenRC will remain, but it would do nothing. The more things you
add to your system, the more packages will be affected by the change,
in either direction. Also, systemd requires more kernel configure
options enabled than OpenRC.

To change back, usually you will only need to unemerge systemd, emerge
udev, and perhaps USE="-systemd" emerge -uDNvp @world. Be warned that
the best thing to do is to do it from a LiveCD; if you boot with
systemd, and uninstalled it, I don't think the shutdown would be
clean.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México