Dan asks:
>
> _WHY_ does the HP sometimes corrupt message files on a powerfail? There
> apparently is _no_ filesystem integrity checking on message files. That's
> pretty scary if you ask me.
 
The code to handle message files was moved to NM (from CM) as of release
5.0.
 
Prior to 5.0, I would assume that the problem was related to data in
buffers not getting posted to disk in a timely manner, and/or that the
transaction manager (XM) wasn't involved in the updating of the disk
data.  (No, I don't know if XM is being used in the NM code today,
but since the problem still happens to Dan on 5.0, I'd assume that XM
isn't being used.)
 
> I've had this happen to me several times on several different, unrelated
> programs that use message files for communication.
 
Bottom line for message files:
 
   Always purge and rebuild them after a crash ... make it part of your
   standard startup process.
 
It wouldn't surprise me to discover that named pipes on Unix have the
same problems.
 
--
Stan Sieler                                          [log in to unmask]
                                     http://www.allegro.com/sieler.html