[Btrfs-users] btrfs questions..

[Chris Mason]

On Sat, Feb 23, 2008 at 01:43:36PM +0200, Voni Hakau wrote:
> Hello !
> 
> I'm very interested in btrfs development and I have general questions about it.
> Please accept my apologizes if they are dumb as I'm new to this area,
> and I just want to learn..
> 
> 1. Like the btrfs name implies (b-trees fs..) I guess that it works basically
> like WAFL (and ZFS), is that right ?

All three use copy on write based writeback, but beyond that there are
many differences.

> 
> 2. Are there any big differences between btrfs-wafl-zfs or only small ones ?

I don't know WAFL or ZFS well enough to answer in full, but the short
answer is there are a number of large differences.

> 
> 3. NetApp claims that ZFS has infringed a set of their patents. They say that
> "ZFS was a conscious reimplementation of their WAFL filesystem". What about
> btrfs ? isn't there a risk for a similar lawsuit against btrfs' community ?

Sorry, I'm not a patent lawyer.  I don't know of any patents infringed
by btrfs.

> 
> 4. What about Solid State disks ? Assuming that SSD is the future, will btrfs
> be able to lead even in front of new SSD requirements/limitations/advantages ?

SSD is an important design target, and btrfs already has code (via mount
-o ssd) that tunes for SSD.  There is quite a lot of tuning left to go
in this area, but we already perform well.

-chris