In Folge eines Updates von Debian 9 (Stretch) auf 10 (Buster) kam es zu fehlerhaften Check_MK-Checks:
/omd/sites/monitoring/lib/nagios/plugins/check_mysql -H 192.168.23.42 -u user -p password
/omd/sites/monitoring/lib/nagios/plugins/check_mysql: error while loading shared libraries: libmariadbclient.so.18: cannot open shared object file: No such file or directory
Lösung:
aptitude install libmariadbclient-dev
ln -s /usr/lib/x86_64-linux-gnu/libmariadb.so.3 /usr/lib/x86_64-linux-gnu/libmariadbclient.so.18