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SubjectRe: [PATCH v3 2/2] dm unstripe: Add documentation for unstripe target
On Wed, Dec 13, 2017 at 04:18:06PM -0800, Randy Dunlap wrote:
> Use ASCII characters ___ or ---, not whatever those bottom block characters are.

Argh, sorry, I removed those for an internal review but forgot to remove them here.

>
> > +
> > + The purpose of this unstriping is to provide better QoS in noisy
> > + neighbor environments. When two partitions are created on the
> > + aggregate drive without this unstriping, reads on one partition
> > + can affect writes on another partition. This is because the partitions
> > + are striped across the two cores. When we unstripe this hardware RAID 0
> > + and make partitions on each new exposed device the two partitions are now
> > + physically separated.
> > +
> > + With the module we were able to segregate a fio script that has read and
> > + write jobs that are independent of each other. Compared to when we run
> > + the test on a combined drive with partitions, we were able to get a 92%
> > + reduction in five-9ths read latency using this device mapper target.
>
> 5/9ths
> although I can't quite parse that sentence.

I'll reword it, thanks.

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