Another aspect is a method and apparatus that stores, in a persistent manner, state information indicating...http://www.google.com/patents/US7707151?utm_source=gb-gplus-sharePatent US7707151 - Method and apparatus for migrating dataAdvanced Patent SearchPublication numberUS7707151 B1Publication typeGrantApplication numberUS 10/353,322Publication dateApr 27, 2010Filing dateJan 29, 2003Priority date