Re: Gotchas about pg_verify_checksums

On Tue, Apr 10, 2018 at 1:27 PM, Daniel Gustafsson <daniel(at)yesql(dot)se> wrote:
>> On 10 Apr 2018, at 06:21, Michael Paquier <michael(at)paquier(dot)xyz> wrote:
>> 1) The documentation states that the cluster needs to be offline.
>> Doesn't this imply that the cluster can also be forcibly killed? It
>> seems to me that the documentation ought to say that the cluster needs
>> to be shut down cleanly instead. Mentioning that only in the notes of
>> the documentation would be enough in my opinion.
>
> Does it really imply that? Either way, the tool could potentially be useful
> for debugging a broken cluster so I’m not sure that stating it requires a
> cleanly shut down server is useful. That being said, you’re absolutely right
> that the current wording isn’t great, I think “The cluster must be shut down
> before running..” would be better.

I agree with Michael -- shutting down the server using immediate mode
could lead to torn pages, that crash recovery will need to repair at a
later stage. I think that some strong caveats around this are required
in the pg_verify_checksums docs, at a minimum.

--
Peter Geoghegan