在客户环境中，使用了oracle 10.2.0.4 dataguard技术，通过最大可用性模式进行数据保护。 以下简单测试，当备库关闭后，再
在客户环境中，使用了oracle 10.2.0.4 dataguard技术，通过最大可用性模式进行数据保护。
以下简单测试，当备库关闭后，再重启备库，主库及备库的响应过程。
在备库执行如下步骤：
sql> shutdown immediate;
ora-01109: database not open
database dismounted.
oracle instance shut down.
sql> startup mount;
oracle instance started.
total system global area 1610612736 bytes
fixed size                  2084400 bytes
variable size             385876432 bytes
database buffers         1207959552 bytes
redo buffers               14692352 bytes
database mounted.
sql> alter database recover managed standby database disconnect from session;
database altered.
sql> exit
当备库关闭后，主库立即检测到备库的失败：
tue nov 17 20:34:58 2009
arc1: attempting destination log_archive_dest_2 network reconnect (3113)
arc1: destination log_archive_dest_2 network reconnect abandoned
ping[arc1]: error 3113 when pinging standby standby.
tue nov 17 20:35:17 2009
lgwr: attempting destination log_archive_dest_2 network reconnect (3113)
lgwr: destination log_archive_dest_2 network reconnect abandoned
tue nov 17 20:35:17 2009
errors in file /opt/oracle/admin/oradbt/bdump/oradbt_lgwr_319632.trc:
ora-03113: end-of-file on communication channel
lgwr: network asynch i/o wait error 3113 log 1 service 'standby'
tue nov 17 20:35:17 2009
destination log_archive_dest_2 is unsynchronized
lgwr: failed to archive log 1 thread 1 sequence 3466 (3113)
tue nov 17 20:35:18 2009
lgwr: closing remote archive destination log_archive_dest_2: 'standby' (error 3113)
(oradbt)
tue nov 17 20:35:18 2009
errors in file /opt/oracle/admin/oradbt/bdump/oradbt_lgwr_319632.trc:
ora-01041: internal error. hostdef extension doesn't exist
lgwr: error 1041 closing archivelog file 'standby'
lgwr: error 1041 disconnecting from destination log_archive_dest_2 standby host 'standby'
，