[Cialug] Tar file corruption

[David Bierce]

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 :)
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