Обсуждение: ERROR: XX001 (Critical and Urgent)

Hello All,
   
    Getting ERROR:  XX001: could not read block 17 of relation base/16386/2619: read only 0 of 8192 bytes, While vacuuming database
    Manual vacuuming and Auto vacuuming process constantly taking high CPU, not able to skip corrupted table for vacuuming and dump this message at regular interval.  fsync is off , From strace, found that semop call was in infinite loop.
     
    I have tried with making fsync on, Now manual vacuum process is taking high CPU, Strace unable to show any results (may be dead lock situation)
    and not any error / warning from postgres daemon

    Postgres Version : 8.4.3 (Migrated data from 8.4.1)

What can be issue ? Is it issue coming after database  table corruption, Can fsync on can prevent such (corruption) scenarios ?

Thanks,
Siddharth

Siddharth Shah <siddharth.shah@elitecore.com> wrote:

> * fsync is off*

If you are running the database with fsync off and there is any sort
of unusual termination, your database will probably be corrupted.  I
recommend restoring from your last good backup.  If you don't have
one, recovery is going to be painful; I recommend contracting with
one of the many companies which off PostgreSQL support.  (I'm not
affiliated with any of them.)

> I have tried with making fsync on

That may help prevent further corruption, but will do nothing to
help recover from the damage already done.

> Postgres Version : 8.4.3 (Migrated data from 8.4.1)

What do you mean by that?  You installed 8.4.3 and reindexed hash
indexes?

> What can be issue ? Is it issue coming after database table
> corruption

Yes.

> Can fsync on can prevent such (corruption) scenarios ?

Yes.

-Kevin