When trying to connect to database , error ORA-21561 observed -
[root@ShareoliteLab scripts]# sqlplus shareo/lite1234@ORAINST
SQL*Plus: Release 11.2.0.4.0 Production on Thu Dec 11 20:30:29 2014
Copyright (c) 1982, 2013, Oracle. All rights reserved.
ERROR:
ORA-21561: OID generation failed
[root@ShareoliteLab ~]# tnsping ORAINST
TNS Ping Utility for Linux: Version 11.2.0.4.0 - Production on 11-DEC-2014 20:27:53
Copyright (c) 1997, 2013, Oracle. All rights reserved.
Used parameter files:
/opt/oracle/product/11.2.0/client_1/network/admin/sqlnet.ora
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.20.5.9)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = ORAINST) (SID = ORAINST)))
OK (0 msec)
How we solved :
The entry for host 192.20.5.9 was missing in /etc/hosts.
Added the IP 192.20.5.9 to /etc/hosts
Terminal # cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
192.20.5.9 ShareoliteLab
After this connection was successful.