CentOS - Jun 2019 - os-prober

Semi-OT question: os-prober is in CentOS, but I never see it running. I've
got a server that's Ubuntu 18.04, and it seems to be running it every
night, which confuses me - I can see no reason for that.

Since ubuntu is o/t, feel free to email me offlist - the only thing I've
found in some googling is to chmod -x /etc/grub.d/30_os-prober on the
ubuntu system.

Thanks in advance.

       mark "the install of ubuntu doesn't even have a man page for
               it, while CentOS, of course, does...."