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* Why I lost the last pg_xlog file?
@ 2011-01-27 12:10 Waldomiro <waldomiro@shx.com.br>
2011-01-27 14:17 ` Re: Why I lost the last pg_xlog file? Shaun Thomas <sthomas@peak6.com>
2011-01-27 14:51 ` Re: Why I lost the last pg_xlog file? Kevin Grittner <Kevin.Grittner@wicourts.gov>
0 siblings, 2 replies; 3+ messages in thread
From: Waldomiro @ 2011-01-27 12:10 UTC (permalink / raw)
To: pgsql-performance
Hi,
Yesterday I perform a crash test, but I lost the last pg_xlog file.
Let me explain:
First I did the pg_start_backup
Second I copied the phisical files to the slave server
Third I did the pg_stop_backup
So I run a test,
1) In the master server I created a 100.000 records table
2) I Runned the "checkpoint" command to be sure the table will be saved.
3) I check the pg_xlog, there was created 6 logs, but in the archive
there was only 5.
4) I copied the achives files to the slave server and I created a
recovery.conf and started the slave postgres.
5) Postgres recovered the 5 log files correctly, but the new table did
not came to the slave. I think because the last pg_xlog file was not
archived.
I did not understand why the last file wasnt archieved?
There is a command to be sure all pg_xlog is archived? or I need to copy
the last file to the slave before recovery?
How is the correctly way to perform a recovery in this case?
Thanks,
Waldomiro Caraiani
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Why I lost the last pg_xlog file?
2011-01-27 12:10 Why I lost the last pg_xlog file? Waldomiro <waldomiro@shx.com.br>
@ 2011-01-27 14:17 ` Shaun Thomas <sthomas@peak6.com>
1 sibling, 0 replies; 3+ messages in thread
From: Shaun Thomas @ 2011-01-27 14:17 UTC (permalink / raw)
To: Waldomiro <waldomiro@shx.com.br>; +Cc: pgsql-performance
On 01/27/2011 06:10 AM, Waldomiro wrote:
> 3) I check the pg_xlog, there was created 6 logs, but in the archive
> there was only 5.
xlogs are only "archived" when they'd normally be deleted. If you have
really high data turnover or very frequent checkpoints, that effectively
happens constantly. I'm not sure where the cutoff is, but there's a
certain amount of "reserve" xlog space based on your checkpoint_segments
setting.
It is an archive, after all. pg_start_backup/pg_stop_backup ensure your
backup is consistent, nothing else. Depending on your archives to
capture everything isn't going to work. If you really want everything,
you can either copy the xlogs manually (not safe) or initiate another
backup. You can kinda fudge it doing this:
1. Call pg_current_xlog_location to get the current xlog.
2. Call pg_switch_xlog to force a new xlog.
3. Copy the file from step 1 and anything older than it to your
archive/slave. Doing this *may* confuse the built-in archive system if
your archive_command is too strict.
4. Profit.
--
Shaun Thomas
OptionsHouse | 141 W. Jackson Blvd. | Suite 800 | Chicago IL, 60604
312-676-8870
sthomas@peak6.com
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^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: Why I lost the last pg_xlog file?
2011-01-27 12:10 Why I lost the last pg_xlog file? Waldomiro <waldomiro@shx.com.br>
@ 2011-01-27 14:51 ` Kevin Grittner <Kevin.Grittner@wicourts.gov>
1 sibling, 0 replies; 3+ messages in thread
From: Kevin Grittner @ 2011-01-27 14:51 UTC (permalink / raw)
To: pgsql-performance; Waldomiro <waldomiro@shx.com.br>
Waldomiro <waldomiro@shx.com.br> wrote:
> Yesterday I perform a crash test, but I lost the last pg_xlog
> file.
Did you follow the steps laid out in the documentation?:
http://www.postgresql.org/docs/current/interactive/continuous-archiving.html#BACKUP-PITR-RECOVERY
In particular, I'm wondering if you followed steps 2 and 6 properly.
-Kevin
^ permalink raw reply [nested|flat] 3+ messages in thread
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2011-01-27 12:10 Why I lost the last pg_xlog file? Waldomiro <waldomiro@shx.com.br>
2011-01-27 14:17 ` Shaun Thomas <sthomas@peak6.com>
2011-01-27 14:51 ` Kevin Grittner <Kevin.Grittner@wicourts.gov>
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