Thread: ERROR: cannot read block 15157 of hp_tran: Success

Khangelani Gama <Khangelani.Gama@ucs-software.co.za> writes:
> Please bear with us we are in process of upgrade but many servers are still using version 7.3.4 of PostgreSQL running
onRedHat5 

Egad...

> A certain table seems to be corrupt when trying to select everything from this table, it throws out an error. See the
errorbelow 

> db0303=# SELECT count(*) from hp_tran;
> ERROR:  cannot read block 15157 of hp_tran: Success

This probably indicates that the table has been truncated in mid-block,
ie the file isn't a multiple of 8K long.  Recent versions of PG would
give you a message that made that clearer, but I don't think 7.3 will.
You could try using dd to pad the file out to the next 8K boundary
(with zeroes), but I expect you'll find that the data on that page
is trashed and you'll have to truncate it away instead in order to not
get errors.

> There is no problem with the disc

If the underlying OS is as unmaintained as the database is, you might
well be encountering kernel bugs :-(

            regards, tom lane

Thanks Tom

..but could you please supply with an example on how I should pad the file using dd?


-----Original Message-----
From: pgsql-admin-owner@postgresql.org [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Tom Lane
Sent: Thursday, April 15, 2010 7:55 PM
To: Khangelani Gama
Cc: pgsql-admin@postgresql.org
Subject: Re: [ADMIN] ERROR: cannot read block 15157 of hp_tran: Success

Khangelani Gama <Khangelani.Gama@ucs-software.co.za> writes:
> Please bear with us we are in process of upgrade but many servers are still using version 7.3.4 of PostgreSQL running
onRedHat5 

Egad...

> A certain table seems to be corrupt when trying to select everything from this table, it throws out an error. See the
errorbelow 

> db0303=# SELECT count(*) from hp_tran;
> ERROR:  cannot read block 15157 of hp_tran: Success

This probably indicates that the table has been truncated in mid-block,
ie the file isn't a multiple of 8K long.  Recent versions of PG would
give you a message that made that clearer, but I don't think 7.3 will.
You could try using dd to pad the file out to the next 8K boundary
(with zeroes), but I expect you'll find that the data on that page
is trashed and you'll have to truncate it away instead in order to not
get errors.

> There is no problem with the disc

If the underlying OS is as unmaintained as the database is, you might
well be encountering kernel bugs :-(

                        regards, tom lane

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