Re: Hot Backup with rsync fails at pg_clog if under load

On 23.09.2011 11:02, Linas Virbalas wrote:
> On 9/22/11 6:59 PM, "Euler Taveira de Oliveira"<euler(at)timbira(dot)com> wrote:
>
>>> If needed, I could do that, if I had the exact procedure... Currently,
>>> during the start of the backup I take the following information:
>>>
>> Just show us the output of pg_start_backup and part of the standby log with
>> the following message 'redo starts at' and the subsequent messages up to the
>> failure.
>
> Unfortunately, it's impossible, because the error message "Could not read
> from file "pg_clog/0001" at offset 32768: Success" is shown (and startup
> aborted) before the turn for "redo starts at" message arrives.

It looks to me that pg_clog/0001 exists, but it shorter than recovery
expects. Which shouldn't happen, of course, because the start-backup
checkpoint should flush all the clog that's needed by recovery to disk
before the backup procedure begins to them.

Can you do "ls -l pg_clog" in the master and the backup, and
pg_controldata on the backup dir, and post the results, please?

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com