Re: raid1 vs raid5

[Psalle <psalleetsile@gmail.com>]

I had forgotten about this post and on rethinking about it I realized 
the kind of brain fart I was having. So thanks for the merciful silence ;-)

On 05/01/16 17:24, Psalle wrote:
> Hello all and excuse me if this is a silly question. I looked around 
> in the wiki and list archives but couldn't find any in-depth 
> discussion about this:
>
> I just realized that, since raid1 in btrfs is special (meaning only 
> two copies in different devices), the effect in terms of resilience 
> achieved with raid1 and raid5 are the same: you can lose one drive and 
> not lose data.
>
> So!, presuming that raid5 were at the same level of maturity, what 
> would be the pros/cons of each mode?
>
> As a corollary, I guess that if raid1 is considered a good compromise, 
> then functional equivalents to raid6 and beyond could simply be 
> implemented as "storing n copies in different devices", dropping any 
> complex parity computations and making this mode entirely generic. 
> Since this seems pretty obvious, I'd welcome your insights on what are 
> the things I'm missing, since it doesn't exist (and it isn't planned 
> to be this way, AFAIK). I can foresee consistency difficulties, but 
> that seems hardly insurmountable if its being done for raid1?
>
> Thanks in advance,
> Psalle.