1、错误提示情况  
 sys@CNMMBO> grant sysdba to scott;
 grant sysdba to scott
 *
 ERROR at line 1:
 ORA-01994: GRANT failed: password file missing or disabled
       
 sys@CNMMBO> ho oerr ora 01994
 01994, 00000, "GRANT failed: password file missing or disabled"
 // *Cause:  The operation failed either because the INIT.ORA parameter
 //          REMOTE_LOGIN_PASSWORDFILE was set to NONE or else because the
 //          password file was missing.
 // *Action: Create the password file using the orapwd tool and set the
 //          INIT.ORA parameter REMOTE_LOGIN_PASSWORDFILE to EXCLUSIVE.

2、根据提示分析解决
 sys@CNMMBO> show parameter remote_login   -->查看参数remote_login_passwordfile的值已经是EXCLUSIVE
                                           -->EXCLUSIVE表示登陆时要密码文件认证，且自己使用独占模式(此为默认值)
 NAME                                 TYPE        VALUE
 ------------------------------------ ----------- ------------------------------
 remote_login_passwordfile            string      EXCLUSIVE
  
 sys@CNMMBO> ho ls $ORACLE_HOME/dbs/orapw*    -->查看密码文件，有一个秘密文件存在，但非当前数据库
 /users/oracle/OraHome10g/dbs/orapwCNBO1
  
 sys@CNMMBO> ho orapwd file=$ORACLE_HOME/dbs/orapwCNMMBO password=oracle entries=10 -->使用orapwd重建当前数据库密码文件
 
 sys@CNMMBO> ho ls $ORACLE_HOME/dbs/orapw*
 /users/oracle/OraHome10g/dbs/orapwCNBO1  /users/oracle/OraHome10g/dbs/orapwCNMMBO
 
 sys@CNMMBO> grant sysdba to scott;    -->重建密码文件后再次授予sysdba权限成功
 
 Grant succeeded.