ORA-01113 - ORA-01110

ORA-01113: file 5 needs media recovery ORA-01110: data file 5: '/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/dbs/databases/mdsdfdata.dbf'

prueva a recuperar el datafile:

SQL>conn / as sysdba
connected.
SQL>recover datafile '/usr/lib/oracle/xe/app/oracle/product/10.2.0/server/dbs/databases/mdsdfdata.dbf';

o

SQL>recover database;

finalmente puedes probar de forzar el arranque:

startup force;