What kind of quiscence are you thinking of? It seems to me that applications will simply need to ensure that either no messages are in-flight at the time of the checkpoint or that all such messages have been logged appropriately by the application.

Greg Bronevetsky
Post-Doctoral Researcher
1028 Building 451
Lawrence Livermore National Lab
(925) 424-5756
bronevetsky1@llnl.gov