YaST2 allegedly without root rights

despite running as user root

From time to time I have the dubious pleasure of working with SLES systems. Of course, I also have to interact with yast or yast2 to configure the system and some services. You can think what you like about the philosophy of hiding the actual configuration files behind a GUI, I don’t think much of it - but that’s just a side note.

During my last excursion into the world of this enterprise distribution, I noticed a curious error. I logged into the system, changed my user context to root and started YaST2. I was greeted by the following message:

YaST2 Control Center is not running as root.
You will only see modules which do not require root privileges.

However, everything was fine with my login, as a quick check revealed:

$# whoami
root

After some googling, I then found several threads that were struggling with the same problem. Apparently, the error message occurs relatively frequently and with a variety of problems. It could be because too little RAM is available - but that wasn’t the problem for me.
In another thread a user also had the above problem, here it was due to a missing log directory /var/log/YaST2.
In my case the directory did exist, but the thread put me on the right track - obviously the error occurs when YaST2 cannot write log files. A check with df -h showed a hard drive utilisation of 100% - so of course no files could be written. After cleaning the hard drive, YaST2 was able to run normally again.
Whether in this particular case it is because no log files could be written or whether a full hard drive also causes other problems, I cannot say for sure, as no log files were written.

To summarise, it can be said that the above message appears to be relatively generic and does not necessarily indicate a lack of rights.