Re: [PATCH 0/5] [RFC] RAID-level terminology change

[Martin Steigerwald <Martin@lichtvoll.de>]

Am Sonntag, 10. März 2013 schrieb Harald Glatt:
> > Very good points,
> > 
> > I was also gonna write something by the lines of 'all that matters is
> > achieving the minimum amount of redundancy, as requested by the user,
> > at the maximum possible performance'.
> > 
> > After reading your post now, Roger, I'm much more clear on what I
> > actually wanted to say, which is pretty much the same thing:
> > 
> > In paradise really all I would have to tell btrfs is how many drives
> > I'm willing to give away so that they will be used exclusively for
> > redundancy. Everything else btrfs should figure out by itself. Not
> > just because it's simpler for the user, but also because btrfs
> > actually is in a position to KNOW better.
[…]
> > It sounds quite futuristic to me, but it is definitely something that
> > we have to achieve hopefully rather sooner than later :)
> > 
> > I'm looking forward to it!
> 
> I have to add something to my own message: Even the notion of thinking
> in 'how many devices do I want to give away for redundancy' is
> outdated... What it really comes down to is how much space am I
> willing to sacrifice so that my reliablilty is increasing. Rather than
> addressing that at a per-drive level with a futuristic fs like btrfs I
> think setting a percent value of total space would be best. Here are
> my n hard drives, I want to give up thirty percent of maximum space so
> that basically I can lose that amount of space across any device
> combination and be safe. Do this for me and do it at maximum possible
> performance with the device count, and type, and sizes that I've given
> you. And if I'm not using the filesystem much, if I have tons of space
> free, feel free to build even more redundancy while idle.
> 
> This is pretty much what it would be like in a perfect world, in my
> opinion :) --

Still, the way to a perfect world is done in steps. Thus I agree with Hugo 
to start somewhere and I think for a admin who wants to know and specify 
exactly what is going one the patches Hugo offered for discussions are a 
huge step forward.

I think they are a good base to build upon.

-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
GPG: 03B0 0D6C 0040 0710 4AFA  B82F 991B EAAC A599 84C7