Unifying file systems (was:puppy linux et al.)

[Yioryos Asprobounitis]

--- On Mon, 12/13/10, Daniel Drake <dsd at laptop.org> wrote:

> You can look on lwn.net for articles about unionfs, why its
> so hard
> and why it doesn't work very well yet (and is not yet
> present in
> Linux).
> 
> Scott (ex-OLPC, a big contributor to the current /versions
> scheme)
> made some comments on IRC a few months ago that he had
> tried(/deployed?) unionfs for litl (in the style that you
> describe)
> and that he didn't recommend it.
> 
> Still, certainly something to keep an eye on for the
> future.
> 


I actually tried, and my understanding is that Aufs although the most feature-full and reliable will never make it into the kernel, with 20.000+ lines of undocumented code that no other than the developer really wants to look at.
Union suffers from both features and reliability while union-mount is probably the closest from making it into the kernel, though is still lacking some key features.

All I can say is that Aufs works pretty nice with the olpc kernels and since we (still) maintain our own kernel, might not be such a bad option.

Would be interesting to hear which unionfs variant Scott was talking about and the related problems, so to have a better idea what to look for in the future. 

Best

> Daniel
>