On a booted Fedora 19 system, if you happen to mount an NFS filesystem then the system creates a mount unit configuration for it in systemd.  So:

$ mkdir /mnt/F19
$ mount csfs:/cs/software/fedora/fedora19 /mnt/F19
$ systemctl status mnt-F19.mount

For some reason, this unit is now scheduled before local-fs.target:

$ systemctl show mnt-F19.mount | grep Before
Before=local-fs.target umount.target

But now there is a dependency cycle, because:

local-fs.target is after mnt-F19.mount
mnt-F19.mount is after network.target
network.target is after network.service
network.service is after basic.target
basic.target is after sysinit.target
sysinit.target is after local-fs.target

(this is on a machine with NetworkManager not installed and the SysV network service turned on, but that may not in fact matter).

As a result, when this machine is shut down, the network mount is never unmounted and the shutdown hangs forever.  If I manually unmount all network filesystems before shutting down then the system shuts down cleanly.

The correct thing to do would seem to be to make mnt-F19.mount come before remote-fs.target and not involve local-fs.target at all.

systemd version: systemd-204-9.fc19.x86_64

Possibly related: Bug 988587, Bug 908123