On Dec 9, 2008, at 2:16 AM, Manuel Bouyer wrote:
I'm not even sure FUA is necessery, if the ordered tag is working properly (i.e. the device doesn't merge different writes in its cache, which would break ordering).
Repeat: Ordered tags have nothing to do with whether or not a write is committed to stable storage. But that is precisely what you want for a write to a journal. FUA is the mechanism that is specifically intended to get the behavior you want for a journal.
-- Manuel Bouyer <bouyer%antioche.eu.org@localhost> NetBSD: 26 ans d'experience feront toujours la difference --
-- thorpej