首先强调一点，9204dg配置同10g差不多，就是区别在以下几点上：
1,备库spfile(pfile)
      *.log_archive_start=TRUE
       lock_name_space=second --其值为：sid(异于主库哟）
       instance_name=second --同上理
*.remote_archive_enable='TRUE'



2,构建dg三大部件，注意事项如下:
    a,shutdown immediate主库，cp或tar（select name from v$datafile)的数据文件到指定地
    b,startup 主库，alter database create standby controlfile as '';注意是open,而非10g中的运行在mount状态
    c,构建用于备库pfile
    d,启动备库时，先：startup mount,后：alter database mount standby database;
3，对于密码文件（主备库），在备库$ORACLE_HOME/dbs，请构建orapw,而非同于10g的orapw$ORACLE_SID，呵，，不然你试下，提示找不到密码文件（此出错是在alter database mount standby database,你亲爱的备库哟）

3,如果你备库各对应的dump目录创建不全或不准确，会在startup nomount备库，报如下错误：
[oracle@9istandby centos]$ sqlplus '/as sysdba'

SQL*Plus: Release 9.2.0.4.0 - Production on Thu Feb 4 14:46:29 2010

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Connected to an idle instance.

SQL> startup nomount pfile='/oracle/oradata/centos/init9istandby.ora'
ORA-00444: background process "RECO" failed while starting
ORA-07446: sdnfy: bad value '' for parameter .
SQL> host oerr ora 00444
00444, 00000, "background process \"%s\" failed while starting"
// *Cause:  Usually due to a bad (or non-existent) background process image.
// *Action: Get a good background process image.

SQL> shutdown immediate
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux Error: 2: No such file or directory
SQL> exit
Disconnected
[oracle@9istandby centos]$ sqlplus '/as sysdba'

SQL*Plus: Release 9.2.0.4.0 - Production on Thu Feb 4 14:48:19 2010

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Connected to an idle instance.

SQL> startup nomount pfile='/oracle/oradata/centos/init9istandby.ora'

SQL> startup nomount pfile='/oracle/oradata/centos/init9istandby.ora'
ORA-00444: background process "CKPT" failed while starting
ORA-07446: sdnfy: bad value '' for parameter .
SQL> host oerr ora 07446
07446, 00000, "sdnfy: bad value '%s' for parameter %s."
// *Cause:  The directory specified as the value for the stated parameter could
//          not be used.
// *Action: Make sure the directory you have specified is a valid
//          directory/file specification.

SQL> exit