I'm trying to export a database content to a dump file, so I'm doing the following:

[root@serverId TEST]# ps -ef|grep pmon|grep -v grep
oracle   25371     1  0 Sep29 ?        00:02:22 ora_pmon_SIDPA

[root@serverId TEST]# echo $ORACLE_HOME

[root@serverId TEST]# echo $ORACLE_SID

[root@serverId TEST]# echo $PATH

[root@serverId TEST]# exp userId@//serverId:1521/SIDPA FILE=dumpuserId.dmp LOG=dumpuserId.LOG OWNER=userId

Export: Release - Production on Wed Oct 21 09:10:56 2015

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


EXP-00056: ORACLE error 12154 encountered
ORA-12154: TNS:could not resolve the connect identifier specified
EXP-00000: Export terminated unsuccessfully

[root@serverId TEST]#

As you can see I already set the env vars $ORACLE_HOME and $ORACLE_SID as far as I understand correctly. I also set the PATH, so I think it should work but unfortunately, I does not.

Any comments about what to try will be welcomed.

Thanks in advance!

  • Try: exp userId@"//serverId:1521/SIDPA" FILE=dumpuserId.dmp LOG=dumpuserId.LOG OWNER=userId
    – Philᵀᴹ
    Oct 21, 2015 at 7:46

1 Answer 1


The syntax should be exp username/password@instance , please also check if the listener is running ps -ef|grep tns and if it has the service listed lsnrctl services (the error "ORA-12154: TNS:could not resolve the connect identifier specified" points out that there is a problem related to that). You can also use the new tool expdp which in my opinion is more easy to use. Ex: expdp sys/password schema=userID dumpfile=userID.dmp directory=data_pump_dir logfile=userID_dmp.log . You can see where the data_pump_dir points to from sqlplus select * from dba_directories and even create your own directory CREATE DIRECTORY dmpdir AS '/opt/oracle'; and use it in the directory clause. But if you want to use exp, check the listener and also the syntax of your command.

  • @Phil: Finally what worked out it was to use the command: exp SYSTEM/manager FILE=dumpuserId.dmp LOG=dumpuserId.LOG OWNER=userId. Actually, I know it worked out but I do not know why? Can anybody let me know?
    – pafede2
    Oct 21, 2015 at 8:45

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