I've had persistent problems with a 5 minute hang at shutdown for the last three versions of Kubuntu (13.04, 13.10, and now 14.04). I suspect this is not a KDE-specific problem. Recently, I performed a fresh installation of Kubuntu 14.04 from a live-USB, and shutdown worked normally for about a week. The hang-up is now happening again, and I can't figure out why.
A brief description of the problem:
The hang-up occurs with all methods of initiating a normal shutdown:
Clicking the shutdown or restart button in KDE,
sudo shutdown -h now,
sudo reboot
The shutdown splash screen appears. Using the down-arrow to access verbose messages, I see "Asking all remaining processes to terminate." This message remains for 5 minutes with no disk activity. Finally, a rapid series of messages flurries to the screen:
* All processes ended within 300 seconds... [ OK ]
nm-dispatcher.action: Caught signal 15, shutting down...
ModemManager[852]: <warn> Could not acquire the 'org.freedesktop.ModemManager1' service name
ModemManager[852]: <info> ModemManager is shut down
* Deactivating swap... [ OK ]
* Unmounting local filesystems... [ OK ]
* Will now restart`
Possible Sources of the Problem:
Before the problem re-appeared, I have mainly been doing routine computing. I have kept the system up-to-date using apt-get upgrade and apt-get dist-upgrade. The only other notable incident was a power failure. I do not have the computer connected to a UPS, so the power failure resulted in an immediate shutdown. Could this have corrupted an important file which must be accessed at shutdown? Is there any way that could cause a 5-minute hang-up?
Here is a list of packages that have been updated before the problem appeared:
bash
iotop
dpkg
dpkg-dev
python3-software-properties
libdpkg-perl
software-properties-kde
software-properties-common
akonadi-backend-mysql
libakonadiprotocolinternals1
akonadi-server
firefox-locale-en
firefox
flashplugin-installer
libqapt2
libqapt2-runtime
thunderbird
openjdk-7-jre-headless
thunderbird-locale-en
kubuntu-driver-manager
qapt-deb-installer
openjdk-7-jre
qapt-batch
icedtea-7-jre-jamvm
libelf1
dpkg
dpkg-dev
libdpkg-perl
libjbig0
gettext-base
libgettextpo-dev
libssl1.0.0
libgettextpo0
libasprintf-dev
linux-headers-3.13.0-24
gettext
libasprintf0c2
linux-headers-3.13.0-24-generic
openssl
linux-libc-dev
gstreamer0.10-qapt
kubuntu-desktop
linux-image-extra-3.13.0-24-generic
linux-image-3.13.0-24-generic
I would appreciate any help with this.
