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.

Regards
Raghavendra

.

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.

-- 
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/

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

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
>