[Dovecot] Broken dovecot-uidlist files

[Timo Sirainen]

On Tue, 2009-02-24 at 11:59 +0100, Ulrich Zehl wrote:
> On Tue, Feb 24, 2009 at 08:08:52AM +0100, Ulrich Zehl wrote:
> > On Mon, Feb 23, 2009 at 12:10:29PM -0500, Timo Sirainen wrote:
> > > I suppose looking at a couple of those could verify if it's really just
> > > NFS caching related corruption or something else.
> > 
> > Okay, I will post results when I have them.
> 
> I found a lot of files that hat null bytes in them, but no other problems
> (which could be due to the fact that my uidlist checking script isn't all
> that great).
> 
> I have put two corrupted dovecot-uidlist and the corresponding log files,
> and the check script up at http://www.topfen.net/user/ul/dovecot/. I hope
> that's enough data.

OK. That just confirms file size caching issue:

1. Server A read and cached file's size
2. Server B recreated it as smaller file
3. Server A wanted to append new entry to the file, but used the cached
file size so it wrote past the end of file, causing those NUL bytes in
the middle.
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