Symptoms
On a CloudLinux server, you move the MySQL data directory to a directory other than /var/lib/mysql. Afterward, the sites show database-connection errors.
Description
This issue may occur if the new MySQL data directory is not present in the CageFS map.
Workaround
Add the new MySQL data directory to the CageFS map file at /etc/cagefs/cagefs.mp, then remount CageFS with cagefsctl -M.