The munin rpms from EPEL failed to install correctly on a particular machine. This is why # /usr/sbin/groupadd -r munin groupadd: Can't get unique system GID (no more available GIDs) # but I don't understand why this happens. Even after checking the man pages for groupadd and login.defs, I have been unable to determine what the settings for SYS_GID_MIN/SYS_GID_MAX on RHEL/CentOS are. None of the 5/6 machines I have access to list them in login.defs. Even assuming relatively conservative values of 201/499, resp. (examples from other distros include 101/999), this doesn't add up. # grep munin /etc/group # ypmatch munin group # wc -l /etc/group 100 /etc/group # grep SYS_GID /etc/login.defs # Any ideas? Information seems to be pretty thin on the ground.