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Re: RAIDframe level 5 write performance

On Fri, Nov 02, 2012 at 11:06:33PM +0100, Edgar Fu? wrote:
> > What does file write performance look like with WAPBL turned off?
> Well, I havent' tried dd'ing to a file with WAPL turned off, but the figures 
> for creating a lot of files can be found further up in this thread:
> > On the 8k fsbsize FFSv1, it takes 7 seconds with WAPL and 5 without!

I think you're seeing pathological cache flush behavior.  Does this
controller have a nonvolatile cache?  It does, right?

I bet with every WAPBL transaction, it's flushing the whole thing,
even though it doesn't need to.

What happens if you set the cache to write-through for the logical

 Thor Lancelot Simon                                 
   But as he knew no bad language, he had called him all the names of common
 objects that he could think of, and had screamed: "You lamp!  You towel!  You
 plate!" and so on.              --Sigmund Freud

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