Search Postgresql Archives

Re: Recovering database from crashed HD (bad sectors)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On Sun, Jul 19, 2015 at 4:10 AM, Alvaro Herrera <alvherre@xxxxxxxxxxxxxxx> wrote:
Tom Lane wrote:
> Amitabh Kant <amitabhkant@xxxxxxxxx> writes:
> > As for running the sql command as suggested by Tom, here is the result:
> > template1=# select * from pg_class where pg_relation_filenode(oid) = 11678;
>
> >  pg_class |           11 |      83 |         0 |       10 |     0 |
> >   0 |             0 |        8 |       281 |             0 |             0
> > | t           | f           | p              | r       |       26 |
> > 0 | t          | f          | f           | f              | f
> > |          662 | {=r/pgsql} |
>
> That's about the worst possible answer :-(.  Without pg_class, you have
> little hope of telling which is which among the other files; and there
> would be no real commonality with the contents of pg_class from other
> databases in the installation, so no way to jury-rig something.  Moreover,
> because pg_class is consulted *very* early in backend startup, it seems
> entirely likely that the failure you're seeing is only the tip of the
> iceberg; there very possibly are other files that are also missing or
> badly damaged.

I would look for the file in the partition's lost+found directory; with
luck, the file is there.  pg_filedump can identify the number of
attributes each tuple has in each file, if there are many such files;
you need to look for a file whose tuples have 26 attributes (relnatts in
the above row).

--
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

There is no lost+found directory in the recovered files. Since the DB was not critical, and can easily be replaced, we are not inclined towards sending it for professional recovery. As Tom suggested, this would just be the tip iceberg, as even during recovery, there were lots of read errors from the disk. I will recreate the DB from the backups.

Thanks for the help and insights though.

With regards

Amitabh

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]
  Powered by Linux