Why does indexer fail with a message like can load library libmysqlclient.so.6?
You probably don’t have MySQL libraries properly installed. On Linux, just find out where your libmysqlclient.so.6 is, then add the path to this file into /etc/ld.so.conf. Then run ldconfig as root. You can also set the value of the environment variable LD_LIBRARY_PATH to the path to the required dynamic libraries. This works on any OS. Note that this is a general UNIX configuration issue, not only mnoGoSearch specific.