Re: tar error, in pg_start_backup()

Hi All,

Thank you Magnus, Bruce...!!

Regards
Raghavendra

On Tue, Apr 20, 2010 at 7:20 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:

> Magnus Hagander wrote:
> > .
> >
> > On Fri, Apr 16, 2010 at 11:55 AM, raghavendra t
> > <raagavendra(dot)rao(at)gmail(dot)com> wrote:
> > > Hi All,
> > >
> > > For?some setups reason, i started taking Hot backup. In this course I
> have first issued pg_start_backup('backup') and went to the data directory
> for backing up in OS format using the command "tar -cf backup.tar? /data" .
> When i issued this command , tar was generating some errors as show below.
> > >
> > > bash-3.00# tar -cf 16aprilstandby.tar /db-data/
> > > tar: Removing leading `/' from member names
> > > tar: /db-data/base/24643/151667: file changed as we read it
> > > tar: /db-data/base/24643/151764.2: file changed as we read it
> > > tar: /db-data/base/24643/151766: file changed as we read it
> > > tar: /db-data/base/24643/151768: file changed as we read it
> > > tar: /db-data/base/66412/151969: file changed as we read it
> > >
> > > After sometime tar has ended and i also issued pg_stop_backup() and i
> continued the process.
> > >
> > > My question here is, is this errors generated by tar are to worrisome
> or whats happening in the backend.
> > > Is "tar" file is safewell to use. Could you please tell me.
> >
> > Those are not errors, they are warnings. As long as you use
> > pg_start_backup() and pg_stop_backup() before and after the tar, they
> > are perfectly harmless, and can be ignored.
>
> Yes, and the manual does mention this issue:
>
>
> http://developer.postgresql.org/pgdocs/postgres/continuous-archiving.html#BACKUP-BASE-BACKUP
>
> Some file system backup tools emit warnings or errors if the files
> they
> are trying to copy change while the copy proceeds. When taking a
> base
> backup of an active database, this situation is normal and not an
> error.
>
> --
> Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
> EnterpriseDB http://enterprisedb.com
>