Re: [rdiff-backup-users] Probleme with rdiff on smbfs

[Andrew Ferguson]

On Oct 3, 2008, at 12:42 PM, EliW wrote:
> Ok, I seem to have 'fixed' the issue,via issueing the following  
> mount command:
>
> mount -t cifs -o guest,mapchars,nocase,directio //droboshare/ 
> DroboData /mounts/drobo
>
>
> I'm not 100% sure that all of mapchars/nocase/directio need to be  
> included, but they all seem worthwhile for fixing various issues  
> that might come up.
>
> the 'nocase' seems to be the one that specifically fixed the issue.


Eli,

Indeed, the place at which rdiff-backup was failing was in a case- 
sensitivity test. It appears that your server requires the 'nocase'  
option, but cifs did not properly detect that (it is supposed to auto- 
detect that, according to the manpage). I think there is most likely a  
bug in CIFS at the root of this.

The way the code works in that test is:

1) create file 'A'
2) check if file 'a' exists
3) If it does, delete file 'a', verify that file 'A' no longer exists,  
and decide the filesystem is case insensitive.
4) If it does not, delete file 'A', and decide the filesystem is case  
sensitive.

Since the test was failing during step 3 (verify that file 'A' no  
longer exists), which ONLY executes if the filesystem is case  
insensitive, it logically leads me to suspect CIFS. By adding the  
'nocase' option, you are forcing CIFS to treat the share as 'case  
insensitive', which means that rdiff-backup is now always running the  
"assert not upper_a.lstat()" line, but this time, instead of failing,  
it is passing.


I'll add a note about this to the FAQ.


Andrew