Winbind automatically restarting every 5 mins

Today I noticed a sudden slowness of disk-IO on my ClearOS7 server. Looking at the logs there has been a constant repetition of 2 commands every (exactly) 5 mins for the last 8 hours and counting :
servicewatch: sanity checking winbind , followed by
servicewatch: restarting winbind after 30 secs.
The system was not actively used when this started.

This system was originally set up with Samba Domain, which I had removed 2 weeks ago, trying to replace it by Samba. That substitution having failed I knew I had to rebuild my server from scratch but had been too busy doing that while I could do without Samba. The system has worked fine and not been updated during the last 2 weeks. This problem started quite suddenly.

I'm out of clues as to what this is all about. I will rebuild my server but this is just nagging me.