Subject: Re: many "cp: cannot stat xxx No such file or directory" logs in warm
 standby
To: Hong Yao <yahoon1982@gmail.com>, pgsql-admin@lists.postgresql.org
References: 
 <CAFg3ZkVB7q6uo5qGmsimSN=NHATKoh9bjUvSL-OYwe0dBXuuBw@mail.gmail.com>
From: Ian Barwick <ian.barwick@2ndquadrant.com>
Message-ID: <c7b798ef-6b6c-554a-8e01-331e6a47acb4@2ndquadrant.com>
Date: Mon, 28 Sep 2020 14:28:55 +0900
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On 2020/09/28 14:12, Hong Yao wrote:
> 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:

(...)

>   * set restore command in postgresql.conf
>       o /    restore_command = 'cp /var/pg_wal_archive/%f %p' /
>       o /    archive_cleanup_command = 'pg_archivecleanup /var/pg_wal_archive %r'/

(...)

> 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/

This is expected, as PostgreSQL is speculatively looking for files which may have
arrived since the last check.

Per the documentation [1]:

     "The command will be asked for file names that are not present in the archive"

[1] https://www.postgresql.org/docs/current//runtime-config-wal.html#GUC-RESTORE-COMMAND


Regards

Ian Barwick


-- 
Ian Barwick                   https://www.2ndQuadrant.com/
  PostgreSQL Development, 24x7 Support, Training & Services