[Samba] Cases where Samba modifies a file without changing the
lshaw at emitinc.com
Mon Sep 18 23:13:25 GMT 2006
On Tue, 19 Sep 2006, Marc SCHAEFER wrote:
> apart from the mmap(2)ed DBM files that Samba uses, are they any cases
> where Samba will *modify* data files without setting the mtime ?
> I have issues with rsync not seeing changes to Samba exported files
> (md5sum don't match). The mtime is however in the very distant past (say
> 2004), but the content seems to have changed.
Let me guess: these files' names end in the string ".XLS", right?
>From what I've heard, apparently MS, in their infinite wisdom,
decided it would be neat if Excel wrote things into files and
then set their modification time back to what it was before
modifying the files. To me, the intent behind "modification
time" seems fairly obvious, but apparently some bright person
at MS has a different interpretation.
I'm not sure if MS has any documentation about this phenomenon,
but the Unison folks do mention it in a changelog:
+ Excel files are now handled specially, so that the fastcheck
optimization is skipped even if the fastcheck flag is set.
(Excel does some naughty things with modtimes, making this
optimization unreliable and leading to failures during change
 My guess is that Excel writes lock information into
the document's file, and the MS person decided that
"modification time" should be interpreted to apply to the
conceptual document rather than the file, but that's just
a guess. Or maybe they were somehow forced into it because
of http://support.microsoft.com/kb/324491/ .
 at https://svn.cis.upenn.edu/svnroot/unison/trunk/src/NEWS .
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