Re: PITR for postgresql-7.3 - Mailing list pgsql-general

I am trying to run pg_dump on the database with the corrupt table, and
try to restore the database.  I also tried to vacuumdb the database and
get the same error.
I get the following error.

pg_dump <database>
pg_dump: query to obtain list of data types failed: PANIC:  read of clog
file 100, offset 81920 failed: Success
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.

Do I have any options for getting around this error?

Thanks
Mary Ellen

Scott Marlowe wrote:
> On 8/10/07, Mary Ellen Fitzpatrick <mfitzpat@bu.edu> wrote:
>
>> Hi,
>>
>> We are running postgresql-7.3.3 and we had a hardware controller and
>> disk failure on the system.  And of course the database does not appear
>> to be backup anywhere.
>>
>
> Ouch, I feel your pain.
>
>
>> I was reading about PITR and was wondering if that is applicable to my
>> version.  We do have pg_xlog files and I am wondering if there is anyway
>> to recover the data.
>>
>
> Sadly, no.  First off you need a backup of the database from some
> point in the past, then you need to ship it's wal logs off to some
> other machine for storage.  Then you need to be running a version of
> pgsql that supports replaying those logs, which 7.3 definitely
> doesn't.
>
>
>> The error we get when trying to access a very important table is
>>
>> "Invalid page header in block 51 of vuser"
>>
>
> Sounds like a bad page.  Is this access going through an index?  If
> so, then you might be able to access parts of the table with a where
> clause and get most of the database out one select statement at a
> time.
>
>
>> Any help would be appreciated.
>> (upgrades and backups lessons learned)
>>
>
> Just a quick point on the upgrades, there's also updates, which are
> even more important.  7.3 is up to 7.3.19 now, and I'm sure there are
> some very nasty bugs in a version as old as 7.3.3
>
> It might be worth backing up the db from the file system level and
> trying to upgrade your install to 7.3.19 and seeing if that fixes the
> problems.  Probably won't, but worth a try.
>
> also, I don't recall if 7.3 had the zero damaged pages option, but if
> it does, you can use that to get the db more or less up and running
> again.
>
> Good luck, and report back on your progress to see if there's anything
> else we can do to help.
>

--
Thanks
Mary Ellen