Re: [Duplicity-talk] Problem with "wb" mode on a FAT32 partition

[Marcin Zajączkowski]

On 2007-04-17 23:44:31 +0200, Kenneth Loafman wrote:
> Marcin Zajączkowski wrote:
(...)
>> I tried to use Duplicity to backup my profiles, but I have problem
>> probably related with a type of partition (FAT32). Duplicity is unable
>> to create any file (IOError: invalid mode: wb).
>>
>> Simple backup command on a local file system with a verbosity set to 9.
(...)
>> Writing
>> /mnt/dosf/Mozilla/psi/psi-duplicity/duplicity-full.2007-04-06T21:36:31+02:00.vol1.difftar.gpg
>>
(...)
>>     fout = self.open("wb")
>>   File "/usr/lib/python2.4/site-packages/duplicity/path.py", line 448,
>> in open
>>     else: result = open(self.name, mode)
>> IOError: invalid mode: wb
>>
>>
>> duplicity-0.4.2
>> librsync-0.9.7
>>
>> Is it possible to write backup on a FAT32 partition?
> 
> Yes, its possible.  I'm looking at the code for this right now and not
> seeing what could be causing a problem.  Could you tell us
>  - what system you're using,

Fedora Core 5

>  - the full command line,

duplicity -v5 /mnt/dosd/psi/ file:///mnt/dosf/psi/psi-duplicity/

>  - how the mount is done (SMB/CIFS/NFS)?

Both partitions (source and destination) are local partitions mount via
vfat kernel module.
I tried with xfs partition, remote partition mounted by use-sshfs and
everything was fine.

> The 'wb' says to do all writes untranslated (binary), i.e. don't munge
> the line ends.  That would not be a system issue, it's part of the
> Python runtime.  My guess is that it's really a bogus error message.
> Yes, there was an error, but the mode has nothing to do with it.
> 
> Could you try creating a file on that partition with the same name as
> the one duplicity was trying to use.  Windows (I'm guessing a windows
> mount) has different filename character restrictions and the special
> chars in the filename may be causing a problem.

Bingo!

address@hidden dosf]$ python
Python 2.4.3 (#1, Oct 23 2006, 14:19:47)
[GCC 4.1.1 20060525 (Red Hat 4.1.1-1)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> open('duplicity-full.2007-04-06T21:36:31+02:00.vol1.difftar.gpg', 'wb')
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
IOError: invalid mode: wb

It seems to be problem with a file name. In my case with ":".
rdiff-backup (which I use for local backups) at start display

Detected abilities for destination (read/write) file system:
  Characters needing quoting                   '^a-z0-9_ -.'

and quoting other characters. This option could be added to Duplicity,
but it seems to be not a small tweak and as I read on a mailing list
there is a problem with maintaining.
Fortunately (for me) I only made test on a fat32 partition and can use
other to workaround a problem.


Thanks for your help
Marcin