On Cpanel Server with MariaDB, cpanel shows error

“The MySQL server is currently offline.
The adminbin “cpmysql” in the “Cpanel” namespace call to function “DBCACHE” ended prematurely: The subprocess reported the “” (255) error when it ended.”

The error only affected Cpanel. MariaDB worked properly on server and sites had no issue.

This is fixed by setting “Use INFORMATION_SCHEMA to acquire MySQL disk usage” to OFF.

WHM » Server Configuration » Tweak Settings » SQL » Use INFORMATION_SCHEMA to acquire MySQL disk usage