Have updated some configuration  in Oracle server, Once its done just tried to restart Oracle Server. Shows an error when start SQL server using startup command,

#  sqlplus sys/password  as sysdba



SQL> shutdown immediate



SQL> startup



ORA-00838: Specified value of MEMORY_TARGET is too small, needs to be at least  XXXM


solution :

We need to increase memory_target space from init.ora and spfileXE.ora file.
  
To find Oracle HOMEPATH and update it.
 
# echo $ORACLE_HOME

# cd /u01/app/oracle/product/11.2.0/xe/dbs

# vim init.ora
memory_target=2G
#  spfileXE.ora
*.memory_target=405520896


Finally restart your Server,


SQL>  startup

or
 
# /etc/init.d/oracle-xe start