Announce: fedostree/rpm-ostree v2014.3
walters at verbum.org
Tue Jan 21 07:30:43 UTC 2014
On Tue, 2014-01-21 at 07:40 +0100, Dennis Jacobfeuerborn wrote:
> Interesting. I've downloaded the VM Image and tried to understand the
Some bits are documented here
> Apparently there exist sort of two root trees / and /sysroot in
> the system with some links targeting the /sysroot tree.
With OSTree, you boot directly into a chroot - dracut switches root and
starts systemd right after mounting the rootfs. See:
/sysroot is a bind mount to the real root /.
> What I'm
> wondering about is that /dev/mapper/fedora-root is mounted several times
> on /, /var, /usr and /sysroot (twice!) sometimes rw and sometimes ro.
/usr is simply a bind mount to itself so it can be mounted read-only.
This is important because otherwise one could corrupt the object store
in /ostree/repo by mutating the hardlink farm in /usr.
Note the /usr here is
really /ostree/deploy/fedostree/deploy/<checksum.serial>/usr as seen
from the physical root.
/var is a special bind mount to /ostree/deploy/fedostree/var which is
shared between each deployment (chroot).
> The impression I get is that /sysroot is the actual root fs in the image
> and / the ostree directory at least that's what the links seem to
> suggest. I still don't understand the mount-voodoo though. Is there some
> documentation about this available?
I'll look at adding more to the gtk-doc, though I suspect I may need to
make a separate "system administrators new to OSTree" document which is
a bit distinct from the "how to use OSTree underneath your package
manager" document that the current one is.
More information about the devel