Re: [rdiff-backup-users] crash in gzip.py

[Lew Wolfgang]

On 12/13/2015 04:03 AM, Andrea Cozzolino wrote:

On Fri, Dec 11, 2015 at 9:56 PM, Lew Wolfgang <address@hidden> wrote:

Hi Folks,

I occasionally encounter an error that terminates a backup
and requires a "--check-destination-dir" run to recover.

The error seems to be associated with gzip.py being asked to
do a negative seek in write mode.  The docs for gzip.py explicitly
say it can't do this.  I'm not sure about which file(s) cause this
error, bit it might be one of the firefox user  .cache files.  This
is on an openSUSE 13.2 Linux system with rdiff-backup 1.2.8.

Any ideas?

 File "/usr/lib64/python2.7/gzip.py", line 423, in seek
    raise IOError('Negative seek in write mode')
IOError: Negative seek in write mode

Hi Wolfgang,

I have quite the same problem and in the *same* environment

(openSUSE 13.2/rdiff-backup 1.2.8).

I have a broken and, so far, unrecoverable backup store.

Each time I try to backup my home dir, I got a "Negative seek"
error while "Writing file object to
/backup/storage/BackUp/tseenfoo/home-andcoz_broken/rdiff-backup-data/increments/.mozilla/firefox/c3ggw723.suse/content-prefs.sqlite.2015-11-23T02:12:37+01:00.snapshot.gz"

Note that I deleted ~/.mozilla/firefox/c3ggw723.suse directory

in between the last successful backup and the first failure.

Follows an extract of the log (--terminal-verbosity 9) of the
execution of

rdiff-backup --exclude-fifos --exclude-device-files --exclude-sockets --terminal-verbosity 9 --exclude /home/andcoz/.local/share/Steam/SteamApps --exclude /home/andcoz/.mozilla/thunderbird/km324c33.gmail --exclude /home/andcoz/.Wip --exclude /home/andcoz/.mozilla/firefox/*/Cache --exclude /home/andcoz/.cache  /home/andcoz /backup/storage/BackUp/tseenfoo/home-andcoz_broken 2>&1 | tee backup_004.log

Full log (32Mb) is available here: https://www.dropbox.com/s/s7jsxr9mw1hey62/backup_004.log.bz2?dl=0

If I do a rdiff-backup --check and retry the backup,

I'll get the same error, on the same file.

Note that there is *no*
/backup/storage/BackUp/tseenfoo/home-andcoz_broken/rdiff-backup-data/increments/.mozilla/firefox/c3ggw723.suse/content-prefs.sqlite
file in backup directory.

( snipped logs )

Hi Andrea,

I'm re-running with your --terminal-verbosity 9 level.  Before then, I notice
that a directory was removed in my case too.  A "Cache" directory in the .mozilla
hierarchy was removed and re-created as "cache2".  The "Cache" directory existed
in May 12 2014, but apparently was changed due to a Firefox update
sometime after then.

So the common point of failure "seems" to be a removed directory. 

BTW, since rdiff-backup hasn't been updated since 2009, I started to
look around for an alternative.  Alas, rdiff-backup's capabilities seem
to be unique.  I wonder what will happen to it when python 2.x finally
goes away?  I remember complaining to Hans Reiser when I observed
that ReiserFS doesn't have native dump/restore as do the ext filesystems.
He grumbled, "Just use tar".  Well, okay...

Regards,
Lew