Re: Invalid page header

On Wednesday October 20 2004 10:43, Ed L. wrote:
> On Wednesday October 20 2004 10:12, Ed L. wrote:
> > On Wednesday October 20 2004 10:00, Tom Lane wrote:
> > > "Ed L." <pgsql(at)bluepolka(dot)net> writes:
> > > > In other words, how do I calculate which bytes to zero to simulate
> > > > zero_damaged_pages??
> > >
> > > Why simulate it, when you can just turn it on? But anyway, the
> > > answer is "the whole page".
> >
> > Old 7.3.4 installation, didn't realize that feature was there. Thx.
>
> That worked for 3 of 4 cases, but for a fourth, I see the message that
> it's zeroing the page, but then it continues to report invalid page
> header for that block... maybe the header is too fouled up to fix?

I didn't notice zero_damaged_pages because it doesn't show up by default in
the postgresql.conf file, I guess wisely since it is somewhat dangerous to
the forensic evidence.

I fixed the case that zero_damaged_pages didn't by truncating the file at
the precise byte offset reported by pg_filedump for the bad block via
'pg_filedump -if -R ...'

Ed