Re: Suggestion for systemd and /usr on seperate partition

[Jonathan Dowland <jmtd@debian.org>]

Hi,

On Thu, Oct 30, 2014 at 10:27:50AM +0100, Hans wrote:
> I am using systemd and I have /usr mounted on a separate partition as
> well as /var, /home, /boot and /.
> 
> Additionally /usr, /var and /home are luks encrypted. 

If you want this to work, you need to ensure that /usr is mounted by the
initramfs. That means moving the cryptsetup prompting into the initramfs
if it isn't there already. I do not know to what extent the Debian tools
for building an initramfs, or the cryptsetup stuff, will help you to get
this set up right.

> I thought about this problem. Might it be possible, to change systemd
> in that way, that it will start after all partitions are mounted? I
> know, it must be done in the source code, but as I am no coder, I
> cannot do it myself.

Not really, since systemd is the first thing started by the kernel, with
one exception: work done in the initramfs. The point of the initramfs is
to ensure that whatever the kernel needs to mount the "root" filesystem
is available to it, so that can be done prior to starting init. If you
are splitting the root partition up by having a separate /usr, then the
initramfs needs to ensure /usr is available too.

It might be possible to enhance the cryptsetup/mkinitramfs stuff in
Debian to make this easier.


Thanks,

-- 
Jonathan Dowland