When booting a system with systemd /cgroup contains the cgroup hierarchies, and they cannot be unmounted on shutdown (or at least /cgroup/systemd cannot, and hence neither /cgroup). Currently, the halt script tries really hard to unmount the FS in a loop, which ultimately fails, but takes quite some time until it gives up. /etc/rc.d/init.d/halt shoulds simply ignore all directories starting with /cgroup the same way as /proc and /sys are spared.
http://git.fedorahosted.org/git/?p=initscripts.git;a=commitdiff;h=49f8dfb872b73e2cade08ca1156c65f81c47910a
BTW: as it turns out this mount point of the cgroup fs has been mnoved in the kernel, to a place inside of /sys.
/sys/cgroup/...? Or somewhere else?
Reopening. With systemd-8 it now tries to umount /sys/fs/cgroup/systemd and /sys/fs/cgroup on shutdown.
*** Bug 627645 has been marked as a duplicate of this bug. ***
*** Bug 627399 has been marked as a duplicate of this bug. ***
systemd-8-2.fc14,initscripts-9.17-2.fc14 has been submitted as an update for Fedora 14. http://admin.fedoraproject.org/updates/systemd-8-2.fc14,initscripts-9.17-2.fc14
systemd-8-2.fc14, initscripts-9.17-2.fc14 has been pushed to the Fedora 14 testing repository. If problems still persist, please make note of it in this bug report. If you want to test the update, you can install it with su -c 'yum --enablerepo=updates-testing update systemd initscripts'. You can provide feedback for this update here: http://admin.fedoraproject.org/updates/systemd-8-2.fc14,initscripts-9.17-2.fc14
initscripts-9.17-2.fc14, systemd-8-3.fc14 has been pushed to the Fedora 14 stable repository. If problems still persist, please make note of it in this bug report.