Home » RDBMS Server » Server Administration » ORA-12547: TNS:lost contact while login as sysdba
ORA-12547: TNS:lost contact while login as sysdba [message #582500] Thu, 18 April 2013 21:00 Go to next message
Messages: 1
Registered: April 2013
Junior Member
ORA-12547: TNS:lost contact

Identify the issue
truss -aefo sqlplus.trc sqlplus /nolog
connect / as sysdba

Cause I
shared memory or semaphores leftover from previous instances (abnormal termination)
ipcs -a
remove problematic shared memory segments & semaphores
ipcrm -m & ipcrm -s
delete $ORACLE_HOME/dbs/lk<SID> file

Cause II
The /proc file system is not mounted.

Cause III
ulimit settings for 'open files' and 'pipe size' is very low.

$ulimit -n 4096
$ulimit -p 30

Cause IV
The stack limit is set too low.

ulimit -s 32768

Cause V

Set proper LD_LIBRARY_PATH path

Cause VI
dbs folder missing from oracle home
mkdir dbs and then create password & init files

Cause VII
Invalid env variables

echo $PATH

Cause VIII
Wrong file permissions

ls -l oracle

chmod 6751 oracle

or relink all
Re: ORA-12547: TNS:lost contact while login as sysdba [message #582503 is a reply to message #582500] Thu, 18 April 2013 21:53 Go to previous messageGo to next message
Messages: 26766
Registered: January 2009
Location: SoCal
Senior Member
Please read and follow the forum guidelines, to enable us to help you:


And your question is what exactly?
Re: ORA-12547: TNS:lost contact while login as sysdba [message #582510 is a reply to message #582500] Fri, 19 April 2013 00:26 Go to previous message
Michel Cadot
Messages: 68043
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
ORA-12547: TNS:lost contact
 *Cause: Partner has unexpectedly gone away, usually during process
 *Action: Investigate partner application for abnormal termination. On an
 Interchange, this can happen if the machine is overloaded.


[Updated on: Fri, 19 April 2013 00:26]

Report message to a moderator

Previous Topic: DBname changed from pfile
Next Topic: ORA-00554 initialization of internal recovery manager package failed
Goto Forum:

Current Time: Thu Dec 02 06:57:50 CST 2021