On Mon, Aug 23, 2010 at 02:30:33PM +0200, Tejun Heo wrote:

It might be useful to give several example configurations with
different cache configurations.  I don't have much experience with
battery backed arrays but aren't they suppose to report write through
cache automatically?

They usually do.  I have one that doesn't, but SYNCHRONIZE CACHE on
it is so fast that it effectively must be a no-op.