Enable WAL Archive in Replication server

Hi,

I want to archive WAL log files in the replication server as well, the postgresql.conf is added with following new lines, after restarting PG, the /var/pgsql/data/archive/ is still empty after 1 hour:

### new lines added today
#
# to enable the replica as Hot Standby
hot_standby = on
#
# to enable WAL archive (coped from master's conf)
wal_level = hot_standby
max_wal_senders = 5
wal_keep_segments = 500
wal_sync_method = fsync
fsync = on
archive_mode = on
archive_command = 'test ! -f /var/pgsql/data/archive/%f && cp %p /var/pgsql/data/archive/%f'
###

ls -la /var/pgsql/data/archive/
total 8
drwx------ 2 postgres root 4096 Aug 11 16:12 ./
drwx------ 3 postgres root 4096 Aug 10 10:59 ../

PG: 9.2.4
OS: Ubuntu 12.04

I am new to Streaming Replication, can you please advise why there is no WAL archive files found in the archive folder?

regards