mysql server does not start

i made a different datadir and gave ownership and rights to mysql and trsted with su that mysql can read host.frm still errno 13: cannot acess ./mysql/host.frm my datadir comtains the mysql dir/schema pls help! i run ununtu thanks nicu

database not listed

Hi, A directory in datadir does not show up as database. Please help! drwx-- 2 mysql root 24576 oct 9 00:34 *opendental* drwx-- 2 mysql mysql 4096 mar 22 19:54 performance_schema drwx-- 2 mysql root 4096 mar 22 19:53 test mysql show databases - \g