*************************************************************************** Internet email is not to be treated as a secure means of communication. North Yorkshire Police monitors all internet email activity and content. This communication is intended for the addressee(s) only. Please notify the sender if received in error. Unauthorised use or disclosure of the content may be unlawful. Opinions expressed in this document may not be official policy. Thank you for your co-operation. *************************************************************************** Kalyan I think this is right. When starting the standby database so that you can recover the archive logs you should do Startup nomount Alter database mount standby database; You then need to put it into recovery. Alter database recover managed standby database disconnect; Brian -----Original Message----- From: ora-apps-dba-bounce@xxxxxxxxxxxxx [mailto:ora-apps-dba-bounce@xxxxxxxxxxxxx] On Behalf Of Kalyan Sundar Sent: 12 March 2009 10:12 To: ora-apps-dba@xxxxxxxxxxxxx Subject: Dataguard setup Hi All, I am in a process of implementing datagaurd on one of our test database. Please advice. Where in I recieve following error when starting the stand-by database: SQL> startup ORACLE instance started. Total System Global Area 1073741824 bytes Fixed Size 1264892 bytes Variable Size 427819780 bytes Database Buffers 633339904 bytes Redo Buffers 11317248 bytes ORA-01102: cannot mount database in EXCLUSIVE mode Kalyan