An error from listener

Recently I clone an identical EBS environment from PROD, but when I start app services I find that the concurrent manager can't be started due to the listener of app tier.the error is the following:

LSNRCTL> start
Starting /oracle/prodora/8.0.6/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 8.0.6.3.0 - Production
Log messages written to /oracle/prodora/8.0.6/network/admin/apps_pko.log
Listening on: (ADDRESS=(PROTOCOL=tcp)(DEV=6)(HOST=172.17.11.72)(PORT=1526))
Attempted to listen on: (ADDRESS=(PROTOCOL=ipc)(PARTIAL=yes)(QUEUESIZE=1))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 2: No such file or directory

[@more@]

I notice that the end of error info is about Linux Error which shows no such file or directory.

The root cause is due to the missing of hidden directory /var/tmp/.oracle. This directory contains a number of 'special' socket files that are used by local clients to connect via the IPC protocol (sqlnet) to various Oracle processes including the TNS listener.

So the solution is so simple, just like that:

[root@oracle422 tmp]# mkdir .oracle
[root@oracle422 tmp]# chown -R oracle:oinstall /var/tmp/.oracle
[root@oracle422 tmp]# cd .oracle
[root@oracle422 .oracle]# ll
total 4
srwxrwxrwx 1 oracle oinstall 0 May 16 13:20 s#18628.1
[root@oracle422 .oracle]#
[root@oracle422 .oracle]#
[oracle@oracle422 PKO_oracle422]$ lsnrctl

LSNRCTL for Linux: Version 8.0.6.3.0 - Production on 16-MAY-2011 10:36:46

(c) Copyright 1999 Oracle Corporation. All rights reserved.

Welcome to LSNRCTL, type "help" for information.

LSNRCTL> set cur APPS_PKO
Current Listener is APPS_PKO
LSNRCTL> start
Starting /oracle/prodora/8.0.6/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 8.0.6.3.0 - Production
Log messages written to /oracle/prodora/8.0.6/network/admin/apps_pko.log
Listening on: (ADDRESS=(PROTOCOL=tcp)(DEV=6)(HOST=172.17.11.72)(PORT=1526))

Connecting to (ADDRESS=(PROTOCOL=TCP)(Host=oracle422)(Port=1526))
STATUS of the LISTENER
------------------------
Alias APPS_PKO
Version TNSLSNR for Linux: Version 8.0.6.3.0 - Production
Start Date 16-MAY-2011 13:19:09
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security OFF
SNMP OFF
Listener Log File /oracle/prodora/8.0.6/network/admin/apps_pko.log
Services Summary...
FNDFS has 1 service handler(s)
FNDSM has 1 service handler(s)
The command completed successfully
LSNRCTL>