install_driver(mysql) failed: Unable to get DBI state function. DBI not loaded

install_driver(mysql) failed: Unable to get DBI state function. DBI not
loaded

I installed OTRS from a rpm and the web installer /orts/installer.pl stops
with:
Error during AJAX communication. Status: error, Error: Internal Server Error
Apache error_log
install_driver(mysql) failed: Unable to get DBI state function. DBI not
loaded.
/opt/otrs/bin/otrs.CheckModules.pl
DBD::mysql.......................FAILED! Not all prerequisites for this
module correctly installed. YAML::XS.........................Not
installed! (required - use "perl -MCPAN -e shell;" - )
But sudo zypper install perl-DBD-mysql-4.021-27.2.x86_64.rpm has Nothing
to do. and mysql configuration is set as the manual requested.
System is SLES 11 SP2 (x86_64) and special thing: No internet connection!
I guess the question is: Why doesn't perl find DBI:mysql while it's
installed?