Oracle listener can not be started. If you try to start it you get the following error:

<hostname>:<sid>adm $ lsnrctl start [LISTENER_NAME]
LSNRCTL for <OS>: Version – Production on 30-AUG-2012 18:06:43
Copyright (c) 1991, 2014, Oracle.  All rights reserved.
Starting /oracle/<SID>/121/bin/tnslsnr: please wait…
TNSLSNR for <OS>: Version – Production
System parameter file is /oracle/<SID>/121/network/admin/listener.ora
Log messages written to /oracle/<SID>/121/network/log/listener.log
Error listening on: (ADDRESS=(PROTOCOL=IPC)(KEY=<SID>.WORLD))
TNS-12555: TNS:permission denied
TNS-12560: TNS:protocol adapter error
TNS-00525: Insufficient privilege for operation
<OS> Error: 1: Not owner


You have probably wrong user permission settings in socket files

Make sure that both <sid>adm and oracle/ora<sid> have full permissions in the following two directories:

  1. /tmp/.oracle
  2. /var/tmp/.oracle

Correct by changing the ownership and granting more privileges:

  1. chown ora<sid>.dba /tmp/.oracle
  2. chmod 774 /tmp/.oracle

For 12c or any installation under the “oracle” user, please adjust the command line above accordingly.