[afnog] Untar large files

[Stephane Bortzmeyer]

On Wed, Oct 24, 2012 at 03:20:01PM +0200,
 Veronique Umutesi <veronique.umutesi at bsc.rw> wrote 
 a message of 247 lines which said:

> When I do gunzip the tar.gz file which was 100GB becomes 10k!!!

Actually, it is possible. Mathematical reasoning based on the amount
of information in a file: if each possible uncompressed file has one
and one only (otherwise, uncompression would not work) compressed
equivalent, then some files will be larger when compressed.

Could it be a crafted attack? Because usual files do not exhibit this
behaviour. 100 GB was the expected size? (It is a *lot* of data, you
work in bio-informatics or particle physics?)