Arch Linux

fschiff

Member

Registered: 2011-10-06

Posts: 71

Systemd in the initramfs

Interesting video about Redhat using systemd in the initial ramdisk arena

http://linuxplumbers.ubicast.tv/videos/ … initramfs/

unfortunately with very little details.  Is this viable?  Important? 
Is this better than Arch's approach which works pretty easily?

EDIT: There is another video on that site 'Systemd for the User Session' which looks even more interesting.

Last edited by fschiff (2012-10-09 13:38:57)

nomorewindows

Member

Registered: 2010-04-03

Posts: 3,408

Re: Systemd in the initramfs

As far as I know, systemd doesn't start until after udev and mounts root and starts systemd from the root device.

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Rasi

Member

From: Germany

Registered: 2007-08-14

Posts: 1,914

Website

Re: Systemd in the initramfs

*cough*
there is nothing stopping you from putting even a whole DE including X inside of a initramfs

its just questionable, if it makes any sense

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nomorewindows

Member

Registered: 2010-04-03

Posts: 3,408

Re: Systemd in the initramfs

*cough*
there is nothing stopping you from putting even a whole DE including X inside of a initramfs

its just questionable, if it makes any sense

That's what the setup images are so that you can install the distros.
Why not just load the whole root filesystem into memory?  There wouldn't be enough memory left to run the operating system.

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I may have to CONSOLE you about your usage of ridiculously easy graphical interfaces...
Look ma, no mouse.

tomegun

Developer

From: France

Registered: 2010-05-28

Posts: 661

Re: Systemd in the initramfs

Interesting video about Redhat using systemd in the initial ramdisk arena

http://linuxplumbers.ubicast.tv/videos/ … initramfs/

unfortunately with very little details.  Is this viable?  Important? 
Is this better than Arch's approach which works pretty easily?

EDIT: There is another video on that site 'Systemd for the User Session' which looks even more interesting.

In my opinion putting systemd in the initramfs makes perfect sense, and is probably something we want to try at some point in the future. Dave has even done some work to make this possible with mkinitcpio.

The role of the initramfs is to mount / and /usr. However, depending on how that is set up (encryption, network, RAID,...), it might rely on a whole bunch of other services also being started first. All this work, and most importantly, dependency tracking, is in common with how systemd configures all your other mounts.

Moreover, systemd and the initramfs already duplicates some early-setup code because systemd needs to be able to deal with the situation where there was no initramfs (mainly mounting various API filesystems).

In other words, systemd can already essentially do all the things the initramfs does, so it makes a whole lot of sense to unify the two. As always, the devil is in the detail, so before saying if this will happen in Arch or not, we'd have to give it a go and see if all the technicalities can be worked out.