When checking the status of the csf service via systemctl you may see an error similar to the following:
# systemctl status csf
... SNIP ...
Dec 16 08:35:16 hostname.domain.tld csf: open3: exec of /usr/sbin/ipset flush failed: No such file or directory at /usr/sbin/csf line 5447.
This issue happens because the ipset package is not installed.
Please keep in mind that cPanel does not create or support either CSF or ipset.
This information is provided as a courtesy.
Install ipset with the following command:
yum install ipset
After ipset has been installed restart CSF with the following command:
systemctl restart csf