Please help me figure out the cause of frozen system after package install

[Ian Kelling]

I did
/bin/yum -y install samba
My screen immediately went to the fedora logo boot animation, then just
sat there frozen after the animation finished with a screen like this
http://fedoraproject.org/w/uploads/3/3b/F11_Snap_37.png. Ctrl-alt-f2 did
not work, and I had to hold the power button down to shutdown the
machine.

I got the relevant section of log file from journalctl here:
http://www.fpaste.org/75397/

this log entry is notable to me:
systemd[1]: Started Update UTMP about System Reboot/Shutdown.

One thing I have no reason to believe is a problem but I thought I'd
mention. I am running xmonad, and its integration with other parts of
the system have been buggy in the past.

I've had this happen more than once before, but I didn't have time to
try to figure it out. I'd like to figure out why this happened, possibly
report a bug, and avoid it in the future. Any suggestions would be
appreciated.

- Ian Kelling