Whats is the difference? How can I possibly open the .b tar?
As far as I can tell, either ClockworkMod or TAR splits the backup into several files. If you're able to open the
data.ext4.tar.a file, it might be because it has the TAR file headers at its start while
data.ext4.tar.b does not. To get to the data in
data.ext4.tar.b, you probably have to combine the split archive files into one single archive file.
On Linux, try to combine all of your TAR files using one of the following commands:
$ cat data.ext4.tar.a data.ext4.tar.b > data-combined.tar
$ cat data.ext4.tar* > data-combined.tar
Then try to open
data-combined.tar as you would any other TAR file.
Or, if you're doing this on Windows, try one of the following commands:
> copy /b data.ext4.tar.a + data.ext4.tar.b data-combined.tar
> copy /b data.ext4.tar* data-combined.tar
Then try to open data-combined.tar as normal.
In both cases, here are what the commands do. The first command will combine
data-combined.tar. The second command will combine any file in the current directory that begins with
data-combined.tar, so it can be used if you have more than the two files listed.