[dm-devel] [Lsf-pc] [Topic] Bcache

Kent Overstreet koverstreet at google.com
Wed Mar 14 18:17:48 UTC 2012

On Wed, Mar 14, 2012 at 2:12 PM, chetan loke <loke.chetan at gmail.com> wrote:
> I'm not a dm guru but a quick scan at flash-cache seems like it does
> what you are saying. Now, if performance isn't acceptable then hashes
> can be replaced with trees and what-not. Also no one would need to
> re-invent the stacking mechanism. I saw thin support(atleast
> documented) for dm. Plus, no matter what cache you come up with you
> may have to persist/store the meta-data associated with it. And dm
> seems like the right place to abstract that.

Bcache kills flash cache on performance - bcache can do around a
million iops on 4k random reads, and beats it on real world
applications and hardware too (i.e. mysql).

I'm not aware of any real features I'm missing out on by not using dm...

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