ORA-12547: TNS:lost contact错误解决方法

在命令启动oracle时，出现ORA-12547: TNS:lost contact错误。中午好好的纳，下午就不管了。以为是链接失效，关机重启后还是不行。

运行环境：Ubuntu+Oracle 11.2.0

在命令启动oracle时，出现ORA-12547: TNS:lost contact错误。中午好好的纳，下午就不管了。以为是链接失效，，关机重启后还是不行。然后google了一把，找到了下面的解决方法。回想了一下，引起的原因是权限的问题，中午的时候不小心该了oracle安装目录的文件夹的权限，看来oracle的权限不能随便改动。

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Cause

1. This could be due to kernel parameters settings
2. Incorrect permissions on the ORACLE executable

Solution

To implement the solution, please execute the following steps:

1.
This could be due to kernel parameters settings
Please check the notes below that provide the required settings for kernel parameters
Note 169706.1 Oracle Database on AIX,HP-UX,Linux,MacOSX,Solaris,Tru64
Note 201021.1 SOLARIS: Quick Start Guide - 9.2.0 RDBMS Installation

2.
This could be due to Incorrect permissions on the ORACLE.exe
The 'ls' command should show permissions 6751 (as follows)

Please check the following:

$ cd $ORACLE_HOME/bin
$ ls -l oracle

The output should be
-rwsr-s--x 1 oracle dba

If not then please execute the following
$ chmod 6751 oracle

Please also verify if the following are correct

echo $ORACLE_HOME
echo $ORACLE_SID
echo $LD_LIBRARY_PATH
echo $PATH

3.
If the above does not resolve I suggest that you shutdown the database and listener and then
"relink all"
Note 131321.1 How to Relink Oracle Database Software on UNIX
完成以上步骤，再次启动oracle就ok了