ORA-12528: TNS:listener: all appropriate instances are blocking new connections

Symptoms

– Start RMAN to duplicate a new database from existing database, I got the following messages

$ rman target / nocatalog auxiliary sys/12345@mhqa1

Recovery Manager: Release 11.1.0.7.0 – Production on Fri Jun 11 10:19:36 2010

Copyright (c) 1982, 2007, Oracle.  All rights reserved.

connected to target database: CVIQA (DBID=188335673)
using target database control file instead of recovery catalog
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00554: initialization of internal recovery manager package failed
RMAN-04006: error from auxiliary database: ORA-12528: TNS:listener: all appropriate instances are blocking new connections

Causes

Most probably your auxiliary database (in nomount state) is the only instance works on current ORACLE_HOME. Each instance is registered in listener by PMON process, which starts only when database is at least mounted. If there is nothing registered in listener before, instance in blocked.

Workaround

You can do 2 things:
1. Modify listener.ora like this:

SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(GLOBAL_DBNAME = AUXDB)
(ORACLE_HOME = /app/oracle/product/10.2.0/)
(SID_NAME = AUXDB)
)
)
OR
2. Modify tnsnames.ora (10g only!) :

AUXDB =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = AUXDB)(UR=A)
)
)