手工建库启动实例时一个小错误：ORA-00824: cannot set sga_target due to existing internal settings

数据库版本：10G 10.2.0.1   错误：ORA-00824: cannot set sga_target due to existing internal settings, see alert log for more information

参数文件如下：

[oracle@ocm1 dbs]$ ls
initdw.ora  initocm1.ora  init.ora  orapwocm1
[oracle@ocm1 dbs]$ cat initocm1.ora
db_name=ocm1
db_files = 80                                                         # SMALL  
db_file_multiblock_read_count = 8                                     # SMALL  
db_block_buffers = 100                                                 # SMALL  
shared_pool_size = 3500000                                            # SMALL
log_checkpoint_interval = 10000
processes = 250                                                        # SMALL  
sessions = 300
parallel_max_servers = 5                                              # SMALL
log_buffer = 32768                                                    # SMALL
max_dump_file_size = 10240      # limit trace file size to 5 Meg each
global_names = TRUE
control_files = ('/u01/oradata/bys3/control01.ctl', '/u01/oradata/bys3/control02.ctl','/u01/oradata/bys3/control03.ctl')
sga_max_size = 400m
sga_target = 300m
undo_management = auto
启动实例报错如下：
oracle@ocm1 dbs]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Sun Nov 24 14:13:41 2013
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connected to an idle instance.
SQL> startup nomount;
ORA-00824: cannot set sga_target due to existing internal settings, see alert log for more information
SQL> exit
报错原因 ：
Cause     SGA_TARGET >0又设置了db_block_buffers参数。db_block_buffers已经是废弃的了。
If you enable automatic SGA Management by setting SGA_TARGET >0 and also have db_block_buffers(Obsolete parameter) in your parameter file (pfile/spfile)
Startup of Database fails with ORA-00824 Error
解决方法：
A)设置SGA_Target=0，关闭Automatic SGA Mangement自动内存管理
B) 删除 db_block_buffers parameter
C) 使用db_cache_size parameter替换db_block_buffers
我这里删除了db_cache_size参数：
[oracle@ocm1 dbs]$ cat initocm1.ora
db_name=ocm1
db_files = 80                                                         # SMALL  
db_file_multiblock_read_count = 8                                     # SMALL  
log_checkpoint_interval = 10000
processes = 250                                                        # SMALL  
sessions = 300
parallel_max_servers = 5                                              # SMALL
log_buffer = 32768                                                    # SMALL
max_dump_file_size = 10240      # limit trace file size to 5 Meg each
global_names = TRUE
control_files = ('/u01/oradata/bys3/control01.ctl', '/u01/oradata/bys3/control02.ctl','/u01/oradata/bys3/control03.ctl')
sga_max_size = 400m
sga_target = 300m
undo_management = auto
[oracle@ocm1 dbs]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Sun Nov 24 14:14:59 2013
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
Connected to an idle instance.
重启实例成功：
SQL> startup nomount;
ORACLE instance started.
Total System Global Area  419430400 bytes
Fixed Size                  1219784 bytes
Variable Size             201327416 bytes
Database Buffers          213909504 bytes
Redo Buffers                2973696 bytes