Forgot to mention recovery.conf on slave:
standby_mode = 'on'
primary_conninfo = 'host..."
restore_command = 'cp /home/psql-wal-archive/%f "%p"'
archive_cleanup_command = 'pg_archivecleanup /home/psql-wal-archive %r'
The wiki states "If wal_keep_segments is a high enough number to retain the
WAL segments required for the standby server, this [restore_command] may not
be necessary."
Presumably this is referring to wal_keep_segments config on the master, right?