nsupdate question

[Jim Reid]

    >> "Joe Feldman" <josephf at edgix.com> tastet: I was told by a Sun
    >> engineer that nsupdate makes changes to memory only and that it
    >> doesn't actually write/delete resource records into zone files.
    >> Is this true?  I was hoping to write a script using nsupdate to
    >> maintain my DNS.

    The Sun engineer must not have noticed that BIND writes a log
    file of all changes received by nsupdate (or other DNS UPDATE
    client), and that even if the zone file is not updated at once
    it will be updated later, and if BIND crashes before the zone
    file is updated it will read the log file and integrate the
    changes.

    In other words, he was wrong.

Indeed. This Sun engineer clearly hasn't read or understood RFC2136.

   3.5 - Stability

   When a zone is modified by an UPDATE operation, the server must
   commit the change to nonvolatile storage before sending a response to
   the requestor or answering any queries or transfers for the modified
   zone.  It is reasonable for a server to store only the update records
   as long as a system reboot or power failure will cause these update
   records to be incorporated into the zone the next time the server is
   started.  It is also reasonable for the server to copy the entire
   modified zone to nonvolatile storage after each update operation,
   though this would have suboptimal performance for large zones.