You do not have mysqlnd and may have permission issues.
For your first problem, I would recommend you look at [FAIL] Missing PHP extension: mysqlnd [FIX] Please install mysqlnd
For you second, try:
chown -R librenms:librenms /opt/librenms setfacl -d -m g::rwx /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/ setfacl -R -m g::rwx /opt/librenms/rrd /opt/librenms/logs /opt/librenms/bootstrap/cache/ /opt/librenms/storage/