今晚办公楼停电维护，需要提前关闭服务器，为防止异常关闭导致的各种问题，有个测试库，使用shutdown normal停库，结果就是很常见的hang住了。
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操作顺序：
?1. shutdown normal，然后关闭了当前sqlplus窗口。
?从alert日志中看：
?Mon Jun 22 16:50:22 2015
Shutting down instance (normal)
Stopping background process SMCO
Shutting down instance: further logons disabled
这里涉及到shutdown normal的原理，稍后引述。
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?2. 此时重新登录，sqlplus / as sysdba?，执行startup或shutdown immediate命令都提示失败，
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SQL*Plus: Release 11.2.0.1.0 Production on Mon Jun 22 17:03:06 2015
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected.
SQL> startup
ORA-01012: not logged on
SQL> shutdown immediate
ORA-24324: service handle not initialized
ORA-24323: value not allowed
ORA-01090: shutdown in progress - connection is not permitted
Mon Jun 22 16:50:24 2015
Stopping background process CJQ0
Stopping background process QMNC
Stopping background process MMNL
Stopping background process MMON
License high water mark = 125
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ORA-01090提示说正在执行关闭操作，不允许其他连接的操作。
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3. 其实这涉及到normal关闭的原理，他需要等待所有已连接用户中断连接，换句话说，如果仍有连接到库的用户，shutdown的操作就一直等待。这是最完全的关闭方式，但同时是变数最大的，因为可能你不知其他用户什么时候中断。
首先尝试查找出所有连接用户，用kill -9直接杀进程。
可以使用ps -ef查找所有(LOCAL=NO)的进程，LOCAL=NO表示连接不是本地，而是远程。
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ps -ef|grep ora|grep -v grep|grep -v ora_|grep LOCAL=NO|awk '{print $2}'，然后kill -9 进程号
或者
ps -ef|grep ora|grep -v grep|grep -v ora_|grep LOCAL=NO|awk '{print $2}'|xargs kill 从alert日志看：
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Mon Jun 22 16:55:26 2015
Active process 27446 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 27402 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 27555 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 11697 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 14942 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 27559 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 27513 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 26911 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 31993 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 30810 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 27557 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 11684 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 11666 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 27510 user 'oracle11g' program 'oracle@dcsopenNode1'
Active process 11688 user 'oracle11g' program 'oracle@dcsopenNode1'
SHUTDOWN: waiting for logins to complete.
Mon Jun 22 17:01:29 2015
All dispatchers and shared servers shutdown
是提示了所有dispatcher和共享服务关闭，但sqlplus登录后仍是上面的提示。
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4. 尝试关闭监听服务，lsnrctl stop。
问题依旧。
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5. 重登陆执行shutdown abort，强制关闭。
从alert日志看：
USER (ospid: 28558): terminating the instance
Instance terminated by USER, pid = 28558
看样子是关闭了实例。
重新执行sqlplus / as sysdba
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SQL*Plus: Release 11.2.0.1.0 Production on Mon Jun 22 17:43:25 2015
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.
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再次执行startup-shutdown normal，
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SQL> startup
ORACLE instance started.
Total System Global Area 3290345472 bytes
Fixed Size 2217832 bytes
Variable Size 2499807384 bytes
Database Buffers 771751936 bytes
Redo Buffers 16568320 bytes
Database mounted.
Database opened.
SQL> shutdown normal
Database closed.
Database dismounted.
ORACLE instance shut down.
由于现在已经没有连接的用户了，正常启动，正常关闭了。
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