Question on migrating data between PVs in xfs

[Dave Chinner]

On Wed, Aug 10, 2016 at 06:31:32PM +0200, Emmanuel Florac wrote:
> Le Wed, 10 Aug 2016 20:56:39 +1000
> Dave Chinner <david at fromorbit.com> écrivait:
> 
> > Have you lookd at using dm-cache instead of modifying the
> > filesystem?
> > 
> 
> Or bcache, fcache, or EnhanceIO. So far from my own testing bcache is
> significantly faster and dm-cache by far the slowest of the bunch, but
> bcache needs some more loving (his main developer is busy writing
> some new tiered, caching filesystem instead).

Yeah, the problem with bcache is that it is effectively an orphaned
driver. If there are obvious and reproducable performance
differentials between bcache and dm-cache, you should bring them to
the attention of the dm developers to see if they can fix them...

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com