Subject Re: Fixing a corrupt database
Author Paul Klerlein
Where can I find the page layout to try and patch the offending page.


--- In, "Paul Beach" <pabeach@w...> wrote:
> Paul,
> Just checking re. using gfix manually, a number of users forget
that gfix
> will run from the command line, and has a lot more options
available to it,
> than appear in the Server Manager, and that a "gfix" run from the
> Manager will not do everything that gfix from the command line will
> If none of the utilities will work, including and especially gfix,
you have
> a major problem, as the only way that your database could get fixed
would be
> to patch the offending page - and there are no utilities to do
this. It
> would have to be done manually if it is fixable at all.
> From a checksum perspective, I believe the checksum mechanism was
turned off
> for performance reasons on Unix 4.0 ODS 8.0, and on all other
platforms at
> ODS 9.0 (4.2 ?)
> cf.
> 2. Checksum
> " If -ignore is specified, the checksum is specifically
checked in
> validate instead of in the engine. If the checksum is
found to
> be wrong, the error:
> "Checksum error on page xxx"
> is returned. This is harmless when found by validate, and
the page
> will still continue to be validated--if data structures
can be
> validated on page, they will be. If -mend is specified,
the page
> will be marked for write, so that when the page is written
to disk
> at the end of validation the checksum will automatically be
> recalculated.
> Note: For 4.0 only Windows & NLM platforms keep page
> My concern is that the error is being returned by a page early on
in the
> database, and it is a page that is needed for a connection.
> As such it may be possible to fix your database, but it will take
time and
> effort.
> Regards
> Paul