[Cialug] Tar file corruption

[Scott Yates]

Have you tried looking at the file in a hex editor?  I am not at all sure,
but I have this idea in my head that tar archives are not compressed, and
store the file contents in a "head to tail" fashion.



On Tue, Apr 30, 2013 at 2:05 PM, David Bierce <david at bierce.org> wrote:

> I don't care enough about the data enough to pay for it just thought
> someone might know of something obvious I missed, like tar -xcf
> --fix-broken-file :)
>
> Though, there is a bitcoin wallet with .034 bitcoins in it...so it might
> be worth paying someone or actually sitting down and opening the file to
> see what the data looks like if we have another run on bitcoins :)
>
> I tried extracting using 7z, cpio and winzip, but they all barf at the
> same place, thought with 7z and winzip I cannot confirm they don't just
> stop reading after the reach zeros.  In either case it seems like there was
> garbage added into the file, not just a few spots of zeros.
>
>
> On Apr 30, 2013, at 1:56 PM, Scott Yates wrote:
>
> > I don't know if this will help, but they have a  free version you might
> try:
> >
> > http://www.datanumen.com/atr/
> >
> > And wow, 6 hours BEFORE epoch?  I thought the time/date stamp was an
> > unsigned 32bit value.
> >
> >
> > On Tue, Apr 30, 2013 at 1:51 PM, David Bierce <david at bierce.org> wrote:
> >
> >> I tried extracting using --ignore-failed-read and --ignore-zero (as tar
> >> reads zeros as an EOF) but after it extracts the first part of the file
> and
> >> gets to the empty sections (where the bad blocks were zeroed out) and
> it t
> >> starts to throw errors and uncompress lots of garbage when it finally
> gets
> >> back to data.
> >>
> >> I do get some files like this.
> >>
> >> Like this
> >>
> >> mnt/wine/drive_c/windows/system32/d3d9.dll
> >> mnt/wine/drive_c/windows/mono/mono-2.0/lib/mono/2.0/culevel.exe
> >> mnt/wine/drive_c/windows/mono/mono-2.0/lib/mono/2.0/gacutil.exe
> >> tar: Skipping to next header
> >> tar: Archive base-256 value is out of off_t range
> >> tar: Archive value -1099511627776 is out of mode_t range
> >> 0..18446744073709551615
> >> \031 at A\377\377\377\377
> >> tar: \031 at A\377\377\377\377: Unknown file type `z', extracted as normal
> >> file
> >> tar: @A????: implausibly old time stamp 1969-12-31 18:00:00
> >> tar: Skipping to next header
> >>
> >>
> >> Which then fills the rest of the drive with invalid hardlinks with fun
> and
> >> exciting names like ?@A???? and B???C????y??0??) with a time stamp of 6
> >> hours before epoch.
> >>
> >>
> >> On Apr 30, 2013, at 1:11 PM, Tom Pohl wrote:
> >>
> >>> Have you tried the tar option --ignore-failed-read? I think that is the
> >> option that will try to skip past corruption and carry on.
> >>>
> >>> Thanks!
> >>> -Tom
> >>>
> >>> On Apr 30, 2013, at 10:58 AM, David Bierce wrote:
> >>>
> >>>> I have a tar file that was bzip2 compressed and had a few blocks to
> bad
> >> in media transfer, After pulling out the bad blocks, the reconstituted
> tar
> >> file appears to only function until the place in the file where the
> first
> >> block was corrupted.  After the first block it just doesn't read the
> rest
> >> of the data.  I've tried to read the file ignoring zero data, which just
> >> pulls a bunch of junk metadata and file names after the empty block.
>  I've
> >> tried to extract it using CPIO, which has the same problem after the
> empty
> >> block.
> >>>>
> >>>> Does anyone know of a tool that can repair tar files, or at least,
> try.
> >> Or it is time time to go digging deep into the file or give up :)
> >>>> _______________________________________________
> >>>> Cialug mailing list
> >>>> Cialug at cialug.org
> >>>> http://cialug.org/mailman/listinfo/cialug
> >>>
> >>> _______________________________________________
> >>> Cialug mailing list
> >>> Cialug at cialug.org
> >>> http://cialug.org/mailman/listinfo/cialug
> >>
> >> _______________________________________________
> >> Cialug mailing list
> >> Cialug at cialug.org
> >> http://cialug.org/mailman/listinfo/cialug
> >>
> > _______________________________________________
> > Cialug mailing list
> > Cialug at cialug.org
> > http://cialug.org/mailman/listinfo/cialug
>
> _______________________________________________
> Cialug mailing list
> Cialug at cialug.org
> http://cialug.org/mailman/listinfo/cialug
>