ISPConfig 3 Wheezy OpenVZ CT No space left on device

Hello,
magically my vps got updated from Wheezy to Jessie and I am not sure, now my IPSConfig 3 setup in broken.
By the way, there is no error in "user_beancounters".
I have no access to the control panel, so tried to turn debug mode on by editing the file

Code:

/usr/local/ispconfig/server/lib/config.inc.php
and change the line:
$conf["log_priority"] = 2;
to
$conf["log_priority"] = 0;

Yet I get the following message:
"No space left on device"
After failing to edit the PHP file, I discovered that it has been emptied not sure how.
How to progress from here?
Thanks,

 

in the cli use:

Code:

df -h

and paste result here.