Re: Page Checksums - Mailing list pgsql-hackers

From Aidan Van Dyk
Subject Re: Page Checksums
Date
Msg-id CAC_2qU8xZvc9D_aBuOp8RZQjeGLd=+Ha5yD2MNy9WDJVXR=bQg@mail.gmail.com
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In response to Re: Page Checksums  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
List pgsql-hackers
On Tue, Dec 20, 2011 at 12:38 PM, Kevin Grittner
<Kevin.Grittner@wicourts.gov> wrote:

>> I don't think the problem is having one page of corruption.  The
>> problem is *not knowing* that random pages are corrupted, and
>> living in the fear that they might be.
>
> What would you want the server to do when a page with a mismatching
> checksum is read?

But that's exactly the problem.  I don't know what I want the server
to do, because I don't know if the page with the checksum mismatch is
one of the 10GB of pages in the page cache that were dirty and poses 0
risk (i.e. hint-bit only changes made it dirty), a page that was
really messed up on the kernel panic that last happened causing this
whole mess, or an even older page that really is giving bitrot...

a.

--
Aidan Van Dyk                                             Create like a god,
aidan@highrise.ca                                       command like a king,
http://www.highrise.ca/                                   work like a slave.


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