Fix Centos Web Panel and MariaDB Issues

I need help resolving some issues with CentOS Web Panel (CWP) and MariaDB after an upgrade. This needs to be done via Anydesk due to sensitive data and security reasons.

Issues include:
- Disk full error preventing MySQL from starting
- Multiple mysqli_connect errors
- Cannot login to root panel and user

Access to SSH root is available.

Ideal skills and experience:
- Expertise in MariaDB and CWP
- Strong troubleshooting skills
- Task need to be perform via Anydesk only due of sensitive data and security reason

Warning: mysqli_connect(): (HY000/2002): No such file or directory in /usr/local/cwpsrv/htdocs/resources/admin/include/functions.php on line 0

Warning: mysqli_connect(): (HY000/2002): No such file or directory in /usr/local/cwpsrv/htdocs/resources/admin/include/functions.php on line 0

Warning: mysqli_connect(): (HY000/2002): No such file or directory in /usr/local/cwpsrv/htdocs/admin/admin/index.php on line 0

Warning: mysqli_connect(): (HY000/2002): No such file or directory in /usr/local/cwpsrv/htdocs/admin/admin/index.php on line 0


DISK FULL: Can't start MySQL!


Warning: mysqli_error() expects exactly 1 parameter, 0 given in /usr/local/cwpsrv/htdocs/admin/admin/index.php on line 0
Could not connect: