Re: Backup's from standby

On Fri, Aug 19, 2011 at 9:38 AM, Valentine Gogichashvili
<valgog@gmail.com> wrote:
>> > What issue we may face if you take a backups(includes data dir + wal
>> > files)
>> > at standby without LVM snapshot?
>>
>> The backup might be corrupted in arbitrary ways.
>
> And what will happen, if one issues a pg_start_backup() on the master, then
> takes a file-backup on slave, and issues pg_stop_backup() on master again?
> As far as I remember this approach was working for me, considering, that all
> needed WAL files are transferred to the newly created DB copy as well.

Well, I think you would need to verify a few more things:

- The pg_start_backup() will need to have been replayed on the standby
before you start the file copy.
- You will need all the WAL segments beginning at the position where
pg_start_backup() was executed on the master and ending after
pg_stop_backup() was executed on the master.

Assuming you do that, it seems like it ought to work, although I have
not tested it and am not at all sure I'm not missing something.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company