Re: WAL files during a backup

Steve, thanks for your response and your question.

Ok, here is some clarification on the WAL file name used in the example below.

The WAL file name I used in the example is actually 000000010000000000000088, and the backup file name is 000000010000000000000088.0089ED8C.backup.

The WAL file 000000010000000000000088 exists in the data/pg_xlog directory after the backup run is completed. The problem for me is that it wasn't copied to the archive directory.

Since this is a test machine and not much db activity occurring on this server, there have been 6 additional WAL files added to the pg_xlog directory in the last 6 hours since the last backup was performed.

Drew

----- Original Message ----
From: "steve(at)outtalimits(dot)com(dot)au" <steve(at)outtalimits(dot)com(dot)au>
To: windsurferdrew-pg(at)yahoo(dot)com
Cc: pgsql-admin(at)postgresql(dot)org
Sent: Wednesday, August 27, 2008 4:36:24 PM
Subject: Re: [ADMIN] WAL files during a backup

00000001000000000000223387 would usually be the next WAL to be written.
How often are you WALs written out?

On Wed, 27 Aug 2008 07:07:17 -0700 (PDT), windsurferdrew-pg(at)yahoo(dot)com
wrote:
> I have a question regarding the WAL files that are moved during a backup
to
> the "archive directory".
>
> I have setup the postgresql.conf file to have the following archive
> command:
>
> archive_command = 'cp -i %p /var/lib/pgsql/backups/%f </dev/null'
>
> Environment:
> PG Version 8.1.4
> OS: Linux 2.6.18-8.el5
>
> After I have run the pg_hotbackup script, the backups directory contains
> only 2 files:
> 1. The gzipped tar file pg_hotbackup_<timestamp>.tar.gz, and
> 2. a WAL file ".backup" file, (for example
> 00000001000000000000223387.0089ED8C.backup)
>
> The actual WAL file did not get copied to the backups directory. From the
> example above, I would have expected at least 1 WAL file named
> 00000001000000000000223387 to be in the backups directory.
>
> My questions are:
> 1. Is this normal behavior? (perhaps no activity in the DB to cause a WAL
> file write during the backup?)
> 2. If I try to restore the DB without this WAL file, will the restore
> fail?
>
> Thanks in advance
>
> Drew
>
>
>