Comment 174 for bug 1252121

I've recently upgraded from 12.04 to 14.04. In 12.04 all worked perfectly.
I see the same sort of thing as discussed. I attach a log from dbus-monitor.

PrepareForSleep True is sent, sleep state is never reached, PrepareForSleep false is never sent

I have no problem suspend/hybernate via pm-suspend.

sudo /lib/systemd/systemd-sleep suspend
also works fine for suspend, hibernate and hybrid-sleep

systemd/network manager get in a mess. seemingly together (see test results below)

Since I'm on 14.04, I don't have systemd-shim, so this seems to be a systemd problem, not just -shim

I used to have tlp installed, but have purged it, and re-installed systemd, the problem has not cleared.

Test results:

$ sudo gdbus call -y -d org.freedesktop.login1 -o /org/freedesktop/login1 -m org.freedesktop.login1.Manager.Suspend true
>> network manager disables, no suspend

2nd call:
$ sudo gdbus call -y -d org.freedesktop.login1 -o /org/freedesktop/login1 -m org.freedesktop.login1.Manager.Suspend true
Error: GDBus.Error:org.freedesktop.systemd1.LoadFailed: Unit systemd-suspend.service failed to load: No such file or directory. See system logs and 'systemctl status systemd-suspend.service' for details.

$ sudo killall NetworkManager
>> Network returns.

$ sudo gdbus call -y -d org.freedesktop.login1 -o /org/freedesktop/login1 -m org.freedesktop.login1.Manager.Suspend true
>> network manager disables, no suspend

-----------------------------
Test results2:

$ systemctl suspend
>> network manager disables, no suspend (no error msg)

$ systemctl suspend
Failed to issue method call: Unit systemd-suspend.service failed to load: No such file or directory. See system logs and 'systemctl status systemd-suspend.service' for details.
Failed to issue method call: Access denied

$ sudo killall NetworkManager
>> Network returns.
$ systemctl suspend
>> network manager disables, no suspend (no error msg)

$ sudo systemctl status systemd-suspend.service
systemd-suspend.service
   Loaded: error (Reason: No such file or directory)
   Active: inactive (dead)

----------------

$ sudo nmcli nm sleep false
>> NM restarts, however, it is NOT as 'cleansing' as killing NM
As:

$ systemctl suspend
Failed to issue method call: Unit systemd-suspend.service failed to load: No such file or directory. See system logs and 'systemctl status systemd-suspend.service' for details.