I logged in via ssh without any problems from a xterminal. When I started a software with grapical output also nothing happens. (I used xhost + and export DISPLAY= )

Maybe LatencyTop helps to solve the Problem: kjournald has a very large value approx. 2000 in contrast to the other processes, e.g. NetworkManager 4.2

Here, You see that one CPU is the whole time waiting while the other CPUs do not have to do anything. What I understood is that they are waiting on the hard disc. The hard disc is in my case an SSD.

sar -P ALL 1
Linux 3.2.0-64-generic 18.06.2014 _x86_64_ (4 CPU)

14:06:59 CPU %user %nice %system %iowait %steal %idle
14:07:00 all 1,75 0,00 0,75 25,00 0,00 72,50
14:07:00 0 0,00 0,00 1,00 0,00 0,00 99,00
14:07:00 1 5,05 0,00 1,01 0,00 0,00 93,94
14:07:00 2 0,00 0,00 0,00 100,00 0,00 0,00
14:07:00 3 1,00 0,00 2,00 0,00 0,00 97,00

14:07:00 CPU %user %nice %system %iowait %steal %idle

you may check /var/log, probably you can find some related messages. or ~/.xsession-errors

The problems are now solved by upgrade to ubuntu 14.04.

One of the problems was trimming of the ssd:

sudo fstrim -v /

provides output

/: 1825476608 bytes were trimmed

but performing a second trim:

sudo fstrim -v /

should provide the following output:

/: 0 bytes were trimmed

In my case the number of trimmed bytes were slightly increased by every trim. Therefore, I conclude that in my case fstrim in ubuntu 12.04 did not work.


Best Regards