>Oracle 10g + Redhat5, installed and used everything fine, installed user oracle.

Today I started sqlplus with oracle user normally

[abc@rhel4 admin]$ sqlplus/as sysdba

SQL*Plus: Release 10.2.0.1.0 – Production on Thu Apr 23 12:11:25 2009

Copyright (c) 1982, 2005, Oracle. All rights reserved.

Connected to:

Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 – Production

With the Partitioning, OLAP and Data Mining options

SQL>

However, when the listener is started, an error is reported.

[abc@rhel4 admin]$ lsnrctl

LSNRCTL for Linux: Version 10.2.0.1.0 – Production on 23-APR-2009 12:13:06

Copyright (c) 1991, 2005, Oracle. All rights reserved.

Welcome to LSNRCTL, type “help” for information.

LSNRCTL> start

Starting /u01/app/oracle/product/10.2.0/bin/tnslsnr: please wait…

TNSLSNR for Linux: Version 10.2.0.1.0 – Production

System parameter file is /u01/app/oracle/product/10.2.0/network/admin/listener.ora

Log messages written to /u01/app/oracle/product/10.2.0/network/log/listener.log

Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost.localdomain)(PORT=1521)))

Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))

TNS-12555: TNS:permission denied

TNS-12560: TNS:protocol adapter error

TNS-00525: Insufficient privilege for operation

Linux Error: 1: Operation not permitted

The log error message shows that it has something to do with permissions, and finally we found a hidden message.

The /var/tmp/.oracle directory is special, if oracle does not have permission to operate this directory, oracle users cannot access the /var/tmp/.oracle folder.

The method is simple: chmod 777 /var/tmp/.oracle

and you’re good to go.