geom_mirror implementation

[Soren Schmidt]

It seems Lukas Ertl wrote:
> > If there's a good reason ccd(4) is harder to fix than geom_mirror, then
> > you might want to talk to phk about rewriting geom_ccd based on
> > geom_mirror.  I believe scottl and phk have plans to fix raidframe,
> > though, which would address a lot of the present limitations.
> 
> I haven't used ccd or raidframe before, and vinum is still a lot of
> 'voodoo'. I just wanted to play around and do something useful;
> furthermore I learned a real lot about GEOM internals.

HMM!!

Maybe we could end up doing something usefull here for a change...

I would *love* GEOM to grow RAIDX support, so that I just needed to
write the read/write RAID config routines to support Promise/HPT/xxx
RAID's. That would also mean we could end the miserable lifes of
ataraid/vinum/raidframe, which would be a reallygood thing (tm).

But I'll bet this sensible a solution to the RAID problems will
drown in religion/warfare/bikesheds between those involded in 
the above RAID solutions and the usual whiners/armchair generals.

But count me in for this!! 

-Søren