Re: Numerical result out of range in rdb 2.2.6?

[Derek Atkins]

Hi Eric,
Thank you so much for the reply.
I spent multiple days trying things and researching (even after I sent my
original email) and finally determined the problem was with the underlying
connection between Linux and my phone.  And MTP Sucks.
I went through about 4 different MTP-based solutions, including
simple-mtpfs (which is what I've used for years), gvfs, jmpfs, and others
-- none of which solved the issue.
Then I found adbfs, which uses the adb protocol to present a filesystem --
and Lo! and Behold!  I was able to backup my phone!!
So yeah, not a problem with rdiff-backup, but rather a problem with the
underlying filesystem from the phone.
Again, thank you for replying!
-derek

On Tue, June 18, 2024 7:00 am, Eric L. wrote:
> Hi Derek,
>
> I won't be very helpful but the issue appears within the open function
> of Python, so not in the code of rdiff-backup (which doesn't mean that
> we can't do anything about it, just that it is more difficult to
> troubleshoot).
>
>  From the look of it and knowing what I know about Android and MTP, I
> guess an issue with either a user/group ID, time stamp or access rights,
> or even the file descriptor.
> Android looks like POSIX but it doesn't comply to it so you might have
> hit one of those corner cases (why now and not before, no clue).
> I could also imagine that you have an issue with the MTP file system
> giving up on rdiff-backup opening and closing files with high frequency.
> MTP isn't known to be the most performant thing in the world, to say the
> least.
>
> Two more or less helpful hints:
>
> 1. solving the issue would probably require reproducing it with Python
> code to understand the exact cause, before I would be potentially able
> to find a workaround
> 2. as an alternative to MTP (urk!), I've been playing with rdiff-backup
> on my smart-phone with SSH using Termux. I wouldn't say that it was
> production grade, but it worked (I didn't pursue the idea because I
> didn't need it, I was just playing around).
>
> KR, Eric
>
> On 14.06.2024 16:26, Derek Atkins wrote:
>> Hi,
>>
>> I've recently been attempting to backup my phone using rdiff backup.
>> Last
>> backup was successful 3 months ago (yeah, yeah, I know -- I should
>> backup
>> more often).
>>
>> I use mtpfs-simple to mount the phone as a file system on my Fedora-38
>> system and use rdiff-backup (rdiff-backup-2.2.6-3.fc38.x86_64) to sync
>> it
>> to my laptop.  However, lately RDB has been barfing during the backup.
>> The exact file where it errors out changes from attempt to attempt, but
>> the error always appears to be the same:
>>
>> WARNING: Exception '[Errno 34] Numerical result out of range:
>> b'/path/to/file'' raised of class '<class 'OSError'>':
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/robust.py",
>> line
>> 94, in check_common_error
>>     return function(*args)
>>            ^^^^^^^^^^^^^^^
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/rpath.py",
>> line
>> 1129, in open
>>     return open(self.path, mode)
>>            ^^^^^^^^^^^^^^^^^^^^^
>>
>> Traceback (most recent call last):
>>   File "/usr/bin/rdiff-backup", line 33, in <module>
>>     sys.exit(load_entry_point('rdiff-backup==2.2.6', 'console_scripts',
>> 'rdiff-backup')())
>>
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>   File "/usr/lib64/python3.11/site-packages/rdiffbackup/run.py", line
>> 35,
>> in main
>>     sys.exit(main_run(sys.argv[1:]))
>>              ^^^^^^^^^^^^^^^^^^^^^^
>>   File "/usr/lib64/python3.11/site-packages/rdiffbackup/run.py", line
>> 108,
>> in main_run
>>     ret_val |= conn_act.run()
>>                ^^^^^^^^^^^^^^
>>   File
>> "/usr/lib64/python3.11/site-packages/rdiffbackup/actions/backup.py",
>> line 154, in run
>>     backup.mirror_and_increment_compat200(
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py",
>> line
>> 53, in mirror_and_increment_compat200
>>     DestS.patch_and_increment(dest_rpath, source_diffiter, inc_rpath)
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py",
>> line
>> 208, in patch_and_increment
>>     for diff in rorpiter.FillInIter(source_diffiter, dest_rpath):
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/rorpiter.py",
>> line 406, in FillInIter
>>     for rp in rpiter:
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py",
>> line
>> 134, in get_diffs
>>     attach_snapshot(diff_rorp, src_rp)
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/backup.py",
>> line
>> 96, in attach_snapshot
>>     fileobj = robust.check_common_error(
>>               ^^^^^^^^^^^^^^^^^^^^^^^^^^
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/robust.py",
>> line
>> 94, in check_common_error
>>     return function(*args)
>>            ^^^^^^^^^^^^^^^
>>   File "/usr/lib64/python3.11/site-packages/rdiff_backup/rpath.py",
>> line
>> 1129, in open
>>     return open(self.path, mode)
>>            ^^^^^^^^^^^^^^^^^^^^^
>> OSError: [Errno 34] Numerical result out of range: b'/path/to/file'
>>
>>
>> The command-line is:
>>
>> rdiff-backup --exclude-globbing-filelist /path/of/my-excludes
>> /path/to/source-dir /path/of/backup-dir
>>
>>
>> Any ideas?
>>
>> Version 2.2.6 is the latest version available on F38.
>>
>> -derek
>
>
>


-- 
       Derek Atkins                 617-623-3745
       derek@ihtfp.com             www.ihtfp.com
       Computer and Internet Security Consultant