[rdiff-backup-users] rdiff-backup changes .gz files

[Arno Wagner]

Hi,

I do full Linux root partition backups with rdiff-backup
1.2.8 on Debian squeeze. As I have had numerous instances of
silent corruption, I always verify my backups, in this case with

  rdiff-backup --compare-full --exclude-sockets --exclude-other-filesystems 

This verify gives me several "metadata the same, data changed" 
errors, that do not make sense. Examples are

   /usr/share/doc/libssl-dev/demos/tunala/INSTALL.gz
   /usr/share/doc/lrzsz/NEWS.gz
   /usr/share/doc/openssl/doc/apps/rsa.pod.gz
   /usr/share/doc/xfig/LATEX.AND.XFIG.zh_CN.gz

When I compare manually, these files are indeed different, 
but gzip -tv tells me both are fine and they decompress 
to bit-identical files. 

One thing I have noticed is that these files are all pretty old.

What is going on here? As I also use md5sum for integrity checks,
modifying .gz files in a backup is really not a good idea., even
if they decompress the same. In fact changing anything when backing 
up files is not a good idea. Also, with this problem, I have to 
check manually for each verification error whether it is truely an 
error or an instance of this not-really corruption.

To me this looks like a bug in rdiff-backup. 
I have observed this only with .gz files.

Arno
-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: address@hidden 
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
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