[fedora-arm] How do I enable mounting /usr as a separate (read-only) partition on Fedora 17?

[Peter Robinson]

On Wed, Nov 20, 2013 at 9:30 PM, Alex Villací­s Lasso
<a_villacis at palosanto.com> wrote:
> I have this ARM project for which I have installed Fedora 17 armv5tel on a
> SD card. The installation is one small FAT partition where the kernel and
> initramfs files can be placed, and one EXT3 partition where the root
> filesystem lives. This mode of operation boots correctly.
>
> Now I want to move the contents of /usr to a separate partition, and lock
> this partition read-only. After some investigation on how to coax the
> bootloader to load the initramfs, I managed to boot the kernel with the
> initramfs, only to find out that it wants to run /sbin/init . The /sbin is a
> symlink that should end up in /usr, but I specify the root filesystem as the
> rootfs in the kernel commandline, and the initramfs has not mounted /usr to
> resolve all of the symlinks, even after specifying the device in /etc/fstab.
> After some googling, it seems that the /usr separation was not fully
> implemented in Fedora 17, but was completed in Fedora 18.
>
> What do I have to do to enable the /usr separation in Fedora 17? I do not
> really want to port the entire project to Fedora 18, and I think it will be
> easier to just grab the relevant packages or patches from Fedora 18,
> recompile for Fedora 17, install, and then separate the filesystem as
> indicated. Is this doable? What packages should I pick from Fedora 18? I
> know that Fedora 17 is EOL, and I do not expect any updated packages for
> this, but I can recompile packages.

You can't have /usr on a separate partition. It's plain not supported
anymore. Details in the link below and it's off topic for the ARM list
as it's a generic Fedora issue and has been the case for some time
(F-16 or there abouts from memory)

http://freedesktop.org/wiki/Software/systemd/separate-usr-is-broken/