#su - oracle
$sqlplus "/as sysdba"
SQL*plus:Release 10.2.0.1.0 - production on *** 20 18:36:10 2008
Copyright (c ) 1982 ,2005 ,oracle .All rights resered.
ERROR:
ORA-01031:insufficient privileges
Enter user-name

racle
Enter password:
ERROR:
ORA-01034:ORACLE not available
ORA-27101:shared memory Error:2:No such file or directory
SP2-0157:unable to CONNECT to ORACLE after 3 attempts,exiting SQL*Plus
$
数据库已经起动,我安装的时候采取的是默认的安装方式,请问这些是哪方面的问题,我初次安装,