pg_stop_backup still waiting for all required WAL segments to be archived (60 seconds elapsed)

I need to do database replication in linux 7 redhat machine using postgresql-9.3.

I am referring the URL for Configuration

http://blog.terminal.com/postgresql-replication-and-backup-methods/

I completed upto this step in master

3.Pre-configuration activities

4. Configuring the master server

   archive_command = 'cd .'
   

   this is the my archive_command in postgresql.conf

   archive_command = 'rsync -avz postgres@slave_ip_address:/var/lib/pgsql/archive'# command to use to archive a             logfile segment
   

5. Initial replication

   postgres=# select pg_start_backup('f');
   

   after that

   copy the dump to the slave server, except for the xlogs files

   when i executing the stop backup query

   postgres=# select pg_stop_backup();
   

   I am getting below mentioned error

   NOTICE:  pg_stop_backup cleanup done, waiting for required WAL segments to be archived
   WARNING:  pg_stop_backup still waiting for all required WAL segments to be archived (60 seconds elapsed)
   HINT:  Check that your archive_command is executing properly.  pg_stop_backup can be canceled safely, but the database backup will not be usable without all the WAL segments.
   WARNING:  pg_stop_backup still waiting for all required WAL segments to be archived (120 seconds elapsed)
   HINT:  Check that your archive_command is executing properly.  pg_stop_backup can be canceled safely, but the database backup will not be usable without all the WAL segments.
   

   Kindly let me know where i wrong