Thread: Need help with PITR for PostgreSQL 9.4.5

The version you are running is neither up-to-date for its major version (9.4) nor is the major version being supported.

https://www.postgresql.org/support/versioning/

Thoug a functioning backup is good to have before upgrading, especially major versions.

On Wednesday, June 24, 2020, Sri Linux <srilinux09@gmail.com> wrote:

I am trying to do PINT backup and recovery for the standalone database which is not in a cluster. 

That is not possible.  Its unclear what exactly you mead/did though.  Consider sharing actual commands/scripts.

< 2020-06-22 16:34:08.487 CDT >LOG:  WAL file is from different database system: WAL file database system identifier is 6840038030519879233, pg_control database system identifier is 6841285371464745049.

You cannot PITR if the WAL doesn’t match the base backup for the cluster you are trying to restore.

https://www.postgresql.org/docs/9.4/continuous-archiving.html

Or, probably better, consider using a third-party system.

David J.

Greetings,

* Sri Linux (srilinux09@gmail.com) wrote:
> Please find the method used. Please recommend me if I have done
> something wrong...

Yes, you are using 'cp' which is *not* recommended for an archive
command.

> Performing a hot backup using pg_basebackup:
> Create a new folder as the postgres user
> pg_basebackup --xlog --format=t -D /server01/pgbackup/`date %Y%m%d`

Note that your pg_basebackup is going to be copying WAL also, in
addition to the archive_command you've configured.

> Restoring from Backup:
> Extract the contents of base.tar from the backed up folder on top of the PostgreSQL installation folder:
> tar -xf base.tar -C /var/lib/pgsql/9.4/data     (RedHat/CentOS)
> Assuming that there is a single database tar file (named with a number) in the backup, extract the contents of this folder to the /server01 folder:
> tar -xf <number>.tar -C /server01
> Copy any unarchived WAL log files saved from the first step back into the pg_xlog folder appropriate for the OS

Not sure what "first step" means here, but you are configuring PostgreSQL
with a recovery.conf later with a restore command to fetch the WAL it needs
from your archive, so you shouldn't be needing to copy files from one
pg_xlog to another (which is just generally a bad idea..).

Further, the error you're getting, as mentioned, is actually that you've
somehow ended up with WAL for some other cluster in your archive and
when this instance tries to restore it, it complains (quite
understandably).  A sensible tool would prevent this from being able to
happen by checking that the WAL that's being archived to a given
location matches the database that the WAL is for.

As mentioned, you should really be considering using a purpose-built
tool which manages this for you, such as pgbackrest, which has such
checks and provides you with backup/restore commands.

Thanks,

Stephen

Thanks for your support. 

I will try to restore and provide results shortly without restoring pg_xlog file

Regards,

Sri

On Thu, Jun 25, 2020 at 1:09 PM Stephen Frost <sfrost@snowman.net> wrote:

Greetings,

* Sri Linux (srilinux09@gmail.com) wrote:
> Please find the method used. Please recommend me if I have done
> something wrong...

Yes, you are using 'cp' which is *not* recommended for an archive
command.

> Performing a hot backup using pg_basebackup:
> Create a new folder as the postgres user
> pg_basebackup --xlog --format=t -D /server01/pgbackup/`date %Y%m%d`

Note that your pg_basebackup is going to be copying WAL also, in
addition to the archive_command you've configured.

> Restoring from Backup:
> Extract the contents of base.tar from the backed up folder on top of the PostgreSQL installation folder:
> tar -xf base.tar -C /var/lib/pgsql/9.4/data     (RedHat/CentOS)
> Assuming that there is a single database tar file (named with a number) in the backup, extract the contents of this folder to the /server01 folder:
> tar -xf <number>.tar -C /server01
> Copy any unarchived WAL log files saved from the first step back into the pg_xlog folder appropriate for the OS

Not sure what "first step" means here, but you are configuring PostgreSQL
with a recovery.conf later with a restore command to fetch the WAL it needs
from your archive, so you shouldn't be needing to copy files from one
pg_xlog to another (which is just generally a bad idea..).

Further, the error you're getting, as mentioned, is actually that you've
somehow ended up with WAL for some other cluster in your archive and
when this instance tries to restore it, it complains (quite
understandably).  A sensible tool would prevent this from being able to
happen by checking that the WAL that's being archived to a given
location matches the database that the WAL is for.

As mentioned, you should really be considering using a purpose-built
tool which manages this for you, such as pgbackrest, which has such
checks and provides you with backup/restore commands.

Thanks,

Stephen

On Friday, November 6, 2020, Sri Linux <srilinux09@gmail.com> wrote:

Hi All

I have to start Postgres 9.4.5 vacuum for our production environment. Got interrupted with the Linux session, is there a way I can monitor if the vacuum is progressing while I reconnect to the Linux box?

Please start new email threads when you have new questions.

If you run vacuum manually in a session, and then disconnect that session, the vacuum stops just like any other command.

David J.

Thank you very much David

On Fri, Nov 6, 2020 at 2:11 PM David G. Johnston <david.g.johnston@gmail.com> wrote:

On Friday, November 6, 2020, Sri Linux <srilinux09@gmail.com> wrote:

Hi All

I have to start Postgres 9.4.5 vacuum for our production environment. Got interrupted with the Linux session, is there a way I can monitor if the vacuum is progressing while I reconnect to the Linux box?

Please start new email threads when you have new questions.

If you run vacuum manually in a session, and then disconnect that session, the vacuum stops just like any other command.

David J.