I recently got a listener that refused to start on AIX. The message it returned was:
Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC0)))
TNS-12555: TNS: Permission denied
TNS-12560: TNS: Protocol adapter error
TNS-00525: Insufficient privilege for operation
IBM/AIX RISC System/6000 Error: 1: Not owner
Checking the binaries and config files revealed nothing suspect – all were owned by Oracle. So I decided to try a truss:
truss -aefo result.txt lsnrctl start
Somewhere in the file I got my answer:
1785960: 1511613: access(“/tmp/.oracle/sEXTPROC0”, 0) = 0
1785960: 1511613: connext(3, 0x0FFFFFFFFFFF77A0, 106) Err#79 ECONNREFUSED
1785960: 1511613: access(“/tmp/.oracle/sEXTPROC0”, 0) = 0
1785960: 1511613: _poll(0x0000000000000000, 0, 100) = 0
1785960: 1511613: close(3) = 0
1785960: 1511613: socket(1, 1, 0) = 3
1785960: 1511613: connext(3, 0x0FFFFFFFFFFF77A0, 106) Err#79 ECONNREFUSED
1785960: 1511613: access(“/tmp/.oracle/sEXTPROC0”, 0) = 0
I checked in /tmp/.oracle/ and some files were owned by root (apparently someone tried to start the listener as root):
srwxrwxrwx 1 oracle dba 0 2011-05-27 16:46 s#200950.1
srwxrwxrwx 1 root system 0 2011-06-29 10:25 sEXTPROC0
srwxrwxrwx 1 root system 0 2011-06-29 10:25 s#1642742.1
I removed the two files and was able to start the listener.
Oracle stuff 
Thank-you for this! I’ve just spent a frustrating hour trying to work out why my listener wouldn’t start and came across your post – bingo!
You’re welcome, really glad my post was helpful.
Thanks, just pointed me in the right direction and spared me a few hours. In my case, it was upgrade patch files. I just chmoded them to allow group write. Thanks.
You’re welcome.
Thanks for this post (before searchig this wasted 20 mins)
Welcome!
thanks again saved a lot of time !!!!!!!!!!!!!!!
You’re welcome :).
u made my day! :)..thank u for the post…
You’re welcome!
You are awesome! Many thanks!
Welcome 🙂 .
hi
this helped me …
thanks your a lifesaver ..an overnight googling….
thanks again
You are welcome!
very good help. thank you very mcuh.
Glad it helped!
Had the same issue – but files were owned by oracle user,
and after upgrading to clusterware with job roles separation all listeners
had to be running under grid. removing oracle-owned files in /tmp/.oracle solved the issue.
Thank you.
You’re welcome – and thank you for sharing.
This was so helpful.
Resolving a challenge I have been battling for a few hours.
Thanks
Good to hear that it helped.
Warm thanks after spending couple of hours come across ur comment and solved my problem very helpful!!!
Good to hear it’s helpful.
Cool post..
That was the trick! Thanks. `find /var/tmp/.oracle -type f -not -user oracle -delete`