WARNING: <file> failed verification -- update discarded (will try again).

[Wayne Davison]

On Wed, Dec 07, 2005 at 11:38:25AM -0700, Joe Peterson wrote:
> WARNING: jukebox/Frank_Sinatra/The_Main_Event/04-Let_Me_Try_Again.flac
> failed verification -- update discarded (will try again).
> jukebox/Frank_Sinatra/The_Main_Event/12-My_Way.flac
> 
> What does the "WARNING" imply?

It is telling you that the updated file that rsync created didn't match
the checksum that the sender told us.  There are a number of different
ways this can happen (all of them pretty rare, but not impossible):

If this was an update (not a newly-created file):

    - A block checksum may have gotten a match on some local data that
      wasn't really identical, so the constructed file wasn't correct.
      (The redo-pass uses a slightly different block size in order to
      work-around such a rare occurrence.)

    - If someone was modifying the file on the receiving side during the
      interval between rsync generating the checksum data and the local
      data being used to recreate the updated file, that can also cause
      the end result to be incorrect (due to different data being copied
      from what rsync was expecting).

For both updates and new files:

    - If the sender got a read-error reading the file, the checksum is
      forced to be invalid because this is the only current way rsync
      has to tell the receiving side to discard the updated file.
      (The observed behavior is not consistent with this possibility,
      so you can ignore this one.)

    - If the data being sent over the socket was corrupted (somehow), it
      may be that the corruption to occurred inside the file data.  This
      is usually only possible with failing hardware, buggy networking
      drivers, and things like that.

..wayne..