Re: FW: [gnu.org #19126] GNU tar and slack space.

[Stepan Kasal]

Hello,

On Mon, Feb 03, 2003 at 09:32:01AM -0500, Sullivan, George E. wrote:
> Subject: Re: [gnu.org #19126] GNU tar and slack space.
> 
> Does GNU tar archive any data in a blocks slack space.
> We have a set of classified files we need to move from
> one system to another.  However, our security is under
> the impression that tar will pick up data at the end-of-file 
> that might exist from deleted files that has not been 
> written over yet. Will GNU tar only read the exact
> file and avoid this slack space.

I beleive (GNU) tar (in contrast to programs like dump and recover)
reads files, without any direct access to disk.

Thus the problem you describe may not appear.

I'd suggest that you call tar under an ordinary user id.  That way
your operating system ensures no data except those really in the files
can be accessed.  (Programs like dump would refuse to run under non-root
user id, I beleive.)

Is this answer satisfactory?

Stepan Kasal