fedora file system ( re shred )

[tameboy]

With regard to this entry in the shred manual...

*Please note* that `shred' relies on a very important assumption:
that the filesystem overwrites data in place.  This is the traditional
way to do things, but many modern filesystem designs do not satisfy this
assumption.  Exceptions include:

   * Log-structured or journaled filesystems, such as those supplied
     with AIX and Solaris, and JFS, ReiserFS, XFS, Ext3, etc.

   * Filesystems that write redundant data and carry on even if some
     writes fail, such as RAID-based filesystems.

   * Filesystems that make snapshots, such as Network Appliance's NFS
     server.

   * Filesystems that cache in temporary locations, such as NFS version
     3 clients.

   * Compressed filesystems.

   If you are not sure how your filesystem operates, then you should
assume that it does not overwrite data in place, which means that shred
cannot reliably operate on regular files in your filesystem.

Does Fedora use a filesystem that overwrites data in place? Can we safely assume that shred is effective when deleting single files?

Thanks for any advice in advance

[Jman]

The better question is do you use a filesystem that overwrites data in place, as there are many file systems you can run in Fedora. ext3 for example has a journal and I do not know how to reliably destroy data in it.

You cannot assume with full certainty that shred works at all. Traces of information can still exist even after overwriting. The question is now how difficult do you want it to be to recover the data.