Thread: Need help to restore database

Need help to restore database

From
"Lori, Giancarlo"
Date:

Hi all,

we are facing with a struggle problem with PostgreSql database production.

A client system based on pgsql is down because the database raise an error message like “ no left space on device”. We have deleted some log files on this machine and after a system restart the db (and the system) was up&running. After two days the database has crashed again. Looking the postgres log there was an error on xlog file (I have inspected the directory pg_xlog and no files I found it). I’ll try to re-build the xlog file with pg_resetxlog. The utilities has created a new xlog file, the postmaster process run, but any command pg_dump, etc I try to execute failed. The system respond that there are not database in the system. Can anyone help us ?

Thanks in advance

Giancarlo

Re: Need help to restore database

From
Date:
On Tue, 17 Mar 2009 09:50:55 +0100, "Lori, Giancarlo"
<giancarlo.lori@eds.com> wrote:
> Hi all,
> we are facing with a struggle problem with PostgreSql database
> production.
> A client system based on pgsql is down because the database raise an
> error message like " no left space on device". We have deleted some log
> files on this machine and after a system restart the db (and the system)
> was up&running. After two days the database has crashed again. Looking
> the postgres log there was an error on xlog file (I have inspected the
> directory pg_xlog and no files I found it). I'll try to re-build the
> xlog file with pg_resetxlog. The utilities has created a new xlog file,
> the postmaster process run, but any command pg_dump, etc I try to
> execute failed. The system respond that there are not database in the
> system. Can anyone help us ?
>
> Thanks in advance
> Giancarlo

Maybe it's not good idea, but...
First - stop the postgreSQL service.
Make the copy of Your database cluster and existing tablespaces.
Try to run a standalone backend instead normal PostgreSQL, giving for
switch -P name of database "postgres".
You can run it like this (if Your system user, who usually rruns postgresql
service is named "postgres" - when not, use for "su the proper account
name":
su postgres -c "/usr/local/pgsql/bin/postgres -D /home/postgres/bazy -O -P
postgres"
In "standalone backend" You can run SQL commands - run VACUUM FULL.
Press Ctrl+D to leave the standalone backend.
Repeat this all for Your database and other, wchich are listed for VACUUM,
when standalone backend starts.
Read about "standalone backend" in the PostgreSQL documenatation.
If You running PostgreSQL on Windows server, use runas with its specific
options instead su, of course.

Brgds
Adam

Re: Need help to restore database

From
Alvaro Herrera
Date:
Lori, Giancarlo wrote:

> A client system based on pgsql is down because the database raise an
> error message like " no left space on device". We have deleted some log
> files on this machine and after a system restart the db (and the system)
> was up&running. After two days the database has crashed again. Looking
> the postgres log there was an error on xlog file (I have inspected the
> directory pg_xlog and no files I found it). I'll try to re-build the
> xlog file with pg_resetxlog. The utilities has created a new xlog file,
> the postmaster process run, but any command pg_dump, etc I try to
> execute failed. The system respond that there are not database in the
> system.

Looks like somebody deleted critical files to get some space back.

> Can anyone help us ?

Find the most recent backup ...

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.

Re: Need help to restore database

From
Ray Stell
Date:
On Tue, Mar 17, 2009 at 12:01:01PM +0100, adamr@informatyka.gdansk.pl wrote:
> On Tue, 17 Mar 2009 09:50:55 +0100, "Lori, Giancarlo"
> <giancarlo.lori@eds.com> wrote:
> > the postmaster process run, but any command pg_dump, etc I try to
> > execute failed. The system respond that there are not database in the
> > system. Can anyone help us ?


I'm no expert, the quiet from the pros is deafening to me.

What does the postmaster log say when you start up?
What is the exact error msg that you refer to as "there are not database in the system?"
What does the \l meta-command say, anything like this:

template1=# \l
        List of databases
    Name     |  Owner  | Encoding
-------------+---------+----------
 postgres    | pgadmin | UTF8
 template0   | pgadmin | UTF8
 template1   | pgadmin | UTF8
(3 rows)



Re: Need help to restore database

From
Simon Riggs
Date:
On Tue, 2009-03-17 at 09:50 +0100, Lori, Giancarlo wrote:

> we are facing with a struggle problem with PostgreSql database
> production.
>
> A client system based on pgsql is down because the database raise an
> error message like “ no left space on device”. We have deleted some
> log files on this machine and after a system restart the db (and the
> system) was up&running. After two days the database has crashed again.
> Looking the postgres log there was an error on xlog file (I have
> inspected the directory pg_xlog and no files I found it). I’ll try to
> re-build the xlog file with pg_resetxlog. The utilities has created a
> new xlog file, the postmaster process run, but any command pg_dump,
> etc I try to execute failed. The system respond that there are not
> database in the system. Can anyone help us ?

2ndQuadrant has a lot of experience with helping people out with
problems like this, including data recovery from damaged databases.
Please let us know if we can be of any help. Apologies for mentioning
commercial matters on list, though this work helps fund further
developments in this area.

--
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support


R: Need help to restore database

From
"Lori, Giancarlo"
Date:
Thanks to all, I have solved, I have been able to restart the Postgres db, and then after a pg-dump I have created a
newone.
 
Thanks again

-----Messaggio originale-----
Da: Simon Riggs [mailto:simon@2ndQuadrant.com] 
Inviato: martedì 17 marzo 2009 15.10
A: Lori, Giancarlo
Cc: pgsql-admin@postgresql.org
Oggetto: Re: [ADMIN] Need help to restore database


On Tue, 2009-03-17 at 09:50 +0100, Lori, Giancarlo wrote:

> we are facing with a struggle problem with PostgreSql database
> production. 
> 
> A client system based on pgsql is down because the database raise an
> error message like “ no left space on device”. We have deleted some
> log files on this machine and after a system restart the db (and the
> system) was up&running. After two days the database has crashed again.
> Looking the postgres log there was an error on xlog file (I have
> inspected the directory pg_xlog and no files I found it). I’ll try to
> re-build the xlog file with pg_resetxlog. The utilities has created a
> new xlog file, the postmaster process run, but any command pg_dump,
> etc I try to execute failed. The system respond that there are not
> database in the system. Can anyone help us ?

2ndQuadrant has a lot of experience with helping people out with
problems like this, including data recovery from damaged databases.
Please let us know if we can be of any help. Apologies for mentioning
commercial matters on list, though this work helps fund further
developments in this area.

-- 
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support


Re: R: Need help to restore database

From
Ray Stell
Date:
On Tue, Mar 17, 2009 at 03:27:42PM +0100, Lori, Giancarlo wrote:
> Thanks to all, I have solved, I have been able to restart the Postgres db, and then after a pg-dump I have created a
newone. 
> Thanks again

I'd like to learn from your experience.  Perhaps you would be willing to
expand on the events and your actions.