If you are upgrading from release 1.0.3 or later you DO NOT need a dump/reload.
If you are upgrading from a release between 1.0.0RC6 and 1.0.2 (inclusive) and really want a live upgrade read the upgrade section of the 1.0.3 release notes chapter.
Upgrade from any release prior to 1.0.0RC6 requires an hard upgrade.