On Wed, Oct 16, 2013 at 07:22:28PM +0200, Warpme wrote: > On 10/16/13 7:02 PM, Zbigniew Jędrzejewski-Szmek wrote: > >On Wed, Oct 16, 2013 at 06:18:12PM +0200, Warpme wrote: > >>Hi, > >>I want to switch init system from SysV to systemd-196. > >>Sys is PXE booted disk-less appliance with rootfs based on overlayfs. > >> > >>Currently I can PXEboot, successfully switch root from initrd to > >>overlayfs based root, systemd starts and executes many of it's > >>units. > >>Unfortunately user units are failing due / is read-only. > >>When I issue "mount -o remount,rw /" - root becomes rw - so it > >>looks like systemd for some reason isn't remounting root to rw. > >>Interesting is that exactly the same initrd->overlayfs script (see > >>below) works OK for SysV - so I think issue isn't in my pivot_root > >>procedure but rather systemd receives / in rw but leaves in ro (as > >>"mount -o remount,rw /" allows to write to /). > >> > >>Script switching initrd to overlayfs root looks following: > >> > >>/bin/mount -n -t tmpfs none /rw > >>/bin/mkdir -p /rw/rootfs > >>/bin/mount -n -t overlayfs -o > >>lowerdir=/rootfs-ro,upperdir=/rw/rootfs none /rootfs > >>cd /rootfs > >>/bin/mkdir -p initrd proc sys > >>/sbin/pivot_root . initrd > >>exec /usr/sbin/chroot . /usr/lib/systemd/systemd > >> > >>Where issue might be? > >What's in /etc/fstab? > > > >Zbyszek > > > Zbyszku, > > Here is my fstab: > > none / auto remount,rw 0 0 OK, so fstab-generator will ignore the mount point becuase of the 'none'. This means that systemd will not remount it.
Actually, I don't understand why / is mounted read-only: -w is the default for mount, and you don't specify -r anywhere. Maybe it's specific to overlayfs. I think that your best option is to add /bin/mount -o remount,rw / in the script. The other option — modifying systemd — is also possible, but it won't happen without a good reason. Your usecase should be trivially solved by modifying the script, so it's not good enough. Zbyszek _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel