SCdaq generates 'defunct' processes
SCdaq generates defunct processes that cannot be killed. This behaviour is not understood.
I noticed that it can happen when there are dma errors, but more often when a new scdaq is installed while it is still running, or if the conf file parameters are changed while it is running (I don't understand the mechanism of how it breaks for these reasons)
Then it takes a very long time to stop the scdaq service (if it stops at all). The only way to get rid of that process(es) is to reboot the machine
As observed e.g https://its.cern.ch/jira/browse/CMSLITOPS-395.