many "cp: cannot stat xxx No such file or directory" logs in warm standby

Hi all

I am setting up a standby server for my PG-12.4 primary server, following
the doc
https://www.postgresql.org/docs/12/warm-standby.html#STANDBY-SERVER-SETUP
(26.2.4.
Setting Up a Standby Server"
The OSes are CentOS-7.8

The steps on the standby:

- install postgresql-12 (not initdb)
- run pg_basebackup to fill the data folder
- clean pg_wal folder
- set restore command in postgresql.conf
- * restore_command = 'cp /var/pg_wal_archive/%f %p' *
- * archive_cleanup_command = 'pg_archivecleanup
/var/pg_wal_archive %r'*
- touch recovery.signal and standby.signal
- start the postgresql-12 service

But in the standalone logs, i see following errors keep repeating:

*cp: cannot stat ‘/var/pg_wal_archive/000000020000000000000014’: No such
file or directory*
*cp: cannot stat ‘/var/pg_wal_archive/00000003.history’: No such file or
directory*

Below is the content of archive folder
-rw-------. 1 postgres postgres 16777216 Sep 28 00:36
000000010000000000000014
-rw-------. 1 postgres postgres 16777216 Sep 28 00:28
000000010000000000000013
-rw-------. 1 postgres postgres 16777216 Sep 28 00:27
000000020000000000000013
-rw-------. 1 postgres postgres 42 Sep 28 00:26 00000002.history
-rw-------. 1 postgres postgres 340 Sep 28 00:22
000000010000000000000012.00000028.backup
-rw-------. 1 postgres postgres 16777216 Sep 28 00:22
000000010000000000000012
-rw-------. 1 postgres postgres 16777216 Sep 28 00:22
000000010000000000000011
-rw-------. 1 postgres postgres 16777216 Sep 28 00:18
000000010000000000000010

Does it mean my setup is not correct? How should I fix it?

Thanks in advance!

BR,
Yahoon