In this Document

APPLIES TO:

SYMPTOMS

- Not able to make a local connection.
- Getting the following error when trying to connect using Sql*Plus

ERROR:
----------------
ORA-12547: TNS:lost contact

For example:

CAUSE

This could be due to

1. to kernel parameters settings
2. Incorrect permissions on the ORACLE executable
3. Insufficient ulimit setting for stack
4. $ORACLE_HOME/rdbms/lib/config.o is 0 bytes
5. Oracle binaries have not been linked correctly
6. A missing $ORACLE_HOME/dbs directory
   Note that creating an empty dbs directory already solves this error and you can for instance shutdown the instance. However, you will obviously not be able to restart because of the missing parameter file. So, the dbs directory needs to be fully restored.

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

2.  This could be due to incorrect permissions on the ORACLE.exe

Optionally, if you collect the OS trace with:

You may see some (Permission denied) in the trace.1.log like the following:

The 'ls' command should show permissions 6751 (as follows)

Please check permissions by running:

The output should show the correct permission which is:

If not, then please execute the following to correct the permissions:

Please also verify if the following are correct:

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

3. Check the current ulimit setting for stack

ulimit -a

Check the install guide for your specific platform and version of Oracle and set the stack appropriately.

4.  Check to ensure the following two files are not 0 bytes:

If yes, rename the following file:

Then, relink the oracle binary:

5. 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

422173.1

REFERENCES