修改sysman和dbsnmp密码后，EM无法启动

昨天登陆EM后提示sysman与dbsnmp用户密码过期，在该界面修改密码后，em再也进不去。
emctl status dbconsole 已关闭
emctl start dbconsole 失败
vi $ORACLE_HOME/host_sid/sysman/log/emdb.nohup

----- Tue Apr  9 16:09:16 2013::omsRecvDir is set? =  1 -----
----- Tue Apr  9 16:09:16 2013::Console Launched with PID 26043 at time Tue Apr  9 16:09:16 2013 -----
----- Tue Apr  9 16:09:16 2013::osname is linux -----
----- Tue Apr  9 16:09:16 2013::heap size used is 384M -----
----- Tue Apr  9 16:09:16 2013::perm size used is 400M -----
----- Tue Apr  9 16:09:16 2013::joptions used are -server -Xmx384M -XX:MaxPermSize=400M -XX:MinHeapFreeRatio=20 -XX:MaxHeapFreeRatio=40  -----
----- Tue Apr  9 16:09:16 2013::Agent Launched with PID 26065 at time Tue Apr  9 16:09:16 2013 -----
(pid=26065): starting emagent version 10.2.0.4.2
(pid=26065): emagent now exiting abnormally - initialization failure. Consult '.trc' and '.log' files.
----- Tue Apr  9 16:09:20 2013::Checking status of EMAgent : 26065 -----
----- Tue Apr  9 16:09:20 2013::EMAgent exited at Tue Apr  9 16:09:20 2013 with return value 55. -----
----- Tue Apr  9 16:09:20 2013::EMAgent has exited due to initialization failure. -----
----- Tue Apr  9 16:09:20 2013::Stopping other components. -----
----- Tue Apr  9 16:09:20 2013::EMWD Stopping DBConsole. -----
--- [color=orange]DBConsole internal stop. No OC4J admin passwd hence hard stop.[/color] ---
----- Tue Apr  9 16:09:25 2013::Commiting Process death. -----
----- Tue Apr  9 16:09:25 2013::Exiting watchdog loop

解决步骤：
百度谷歌搜了很久，方法大多为修改$ORACLE_HOME/host_sid/sysman/emd/targets.xml或$ORACLE_HOME/host_sid/sysman/config/emoms.properties文件中的加密方式为FALSE并用明文密码替换原来的密文，均无效。差点就要重建em了。。。。。这时，点到一个博客地址：http://orapath.blogspot.ca/2012/04/normal-0-false-false-false-en-us-zh-cn_19.html 依着步骤死马当活马医，然后就可以启动em了。
博文如下：
Thursday, April 19, 2012

Windows DBConsole internal stop. No OC4J admin passwd hence hard stop


Enterprise manager cannot be started. The status shows dbconsole is already started:
C:\>emctl status dbconsole
Oracle Enterprise Manager 11g Database Control Release 11.2.0.1.0
Copyright (c) 1996, 2010 Oracle Corporation.  All rights reserved.
https://JDEORA01:5500/em/console/aboutApplication
Oracle Enterprise Manager 11g is running.
------------------------------------------------------------------
Logs are generated in directory C:\APP\ORACLE\product\11.2.0\se1/jdeora01_e1prod/sysman/log


And it cannot be stopped:
C:\ >emctl stop dbconsole
Oracle Enterprise Manager 11g Database Control Release 11.2.0.1.0
Copyright (c) 1996, 2010 Oracle Corporation.  All rights reserved.
https://JDEORA01:5500/em/console/aboutApplication
The OracleDBConsoleE1PROD service is not started.

More help is available by typing NET HELPMSG 3521.

Log in Emdb.nohup shows:
12/04/19 15:34:11 Error starting ORMI server JDEORA01 port 5,521: Unrecognized Windows Sockets error: 0: JVM_Bind
12/04/19 15:34:11 Shutting down OC4J...
--- DBConsole internal stop. No OC4J admin passwd hence hard stop. ---
----- Thu Apr 19 15:34:15 2012::Commiting Process death. -----
----- Thu Apr 19 15:34:15 2012::Exiting watchdog loop

Find the process id and kill the tree in task manager:
C:\ >emctl status agent
Oracle Enterprise Manager 11g Database Control Release 11.2.0.1.0
Copyright (c) 1996, 2010 Oracle Corporation.  All rights reserved.
---------------------------------------------------------------
Agent Version     : 10.2.0.4.2
OMS Version       : 10.2.0.4.2
Protocol Version  : 10.2.0.4.2
Agent Home        : C:\APP\ORACLE\product\11.2.0\se1\jdeora01_E1PROD
Agent binaries    : C:\APP\ORACLE\product\11.2.0\se1
Agent Process ID  : 1732
Agent URL         : https://JDEORA01:1830/emd/main
Repository URL    : https://JDEORA01:5500/em/upload/
Started at        : 2012-04-16 15:37:38
Started by user   : SYSTEM
Last Reload       : 2012-04-16 15:55:52
Last successful upload                       : 2012-04-19 15:49:04
Total Megabytes of XML files uploaded so far :    32.59
Number of XML files pending upload           :        0
Size of XML files pending upload(MB)         :     0.00
Available disk space on upload filesystem    :    18.32%
Data channel upload directory                : C:/APP/ORACLE/product/11.2.0/se1/jdeora01_E1PROD/sysman/recv
Last successful heartbeat to OMS             : 2012-04-19 15:48:47
---------------------------------------------------------------
Agent is Running and Ready

Kill process 1732 and dbconsole can be started now:
C >emctl status dbconsole
Oracle Enterprise Manager 11g Database Control Release 11.2.0.1.0
Copyright (c) 1996, 2010 Oracle Corporation.  All rights reserved.
https://JDEORA01:5500/em/console/aboutApplication
Oracle Enterprise Manager 11g is running.
------------------------------------------------------------------
Logs are generated in directory C:\APP\ORACLE\product\11.2.0\se1/jdeora01_e1prod/sysman/log

注：我用的是Ubuntu 11.10加Oracle 11.2.0.1.0 64位，也同样有效。