[dm-devel] How to properly benchmark dm-cache

[Mike Snitzer]

On Thu, Aug 31 2017 at  5:29pm -0400,
Remington Brasga <Remington.Brasga at taec.toshiba.com> wrote:

>    Hi, I'm trying to benchmark dm-cache, but I'm having trouble getting the
>    benchmark to show positive results. I've tried TPC-B, TPC-C, TPC-H, SQL,
>    and a handful of other, but I think because they are simulations they
>    don't generate the `hot spots' required to promote blocks to the cache.
> 
>    I know it's easy to show results using FIO with a specific configuration,
>    but I was hoping to use a real benchmark like the ones I've tried.
> 
>    Does anyone have a good set of benchmarks that shows positive results?

Hi Remi,

Which kernel are you testing?

I know Sanjay Rao (cc'd) has done various dm-cache testing with an OLTP
workload against an Oracle DB and that he has seen very solid results
with the latest dm-cache.

I'm not sure if he, or others, tried any of the TPC variants but
hopefully Sanjay can respond with where/how he got dm-cache to respond
well to his tests.

Mike