[Btrfs-users] btrfs questions..

[Voni Hakau]

Hi Chris,

On Mon, Feb 25, 2008 at 7:05 AM, Chris Mason <chris.mason at oracle.com> wrote:
> On Sat, Feb 23, 2008 at 01:43:36PM +0200, Voni Hakau wrote:
> > 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.

Can you please point out a one (or two) major differences ? Only if
it's no hussle..
I have read the WAFL papers, so I know my way around the b-trees COW
ideas, but before I delve into btrfs code I would be happy to know its
theoretical headlines
and main difference from WAFL..

> > 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.

That's nice. are these tuning an inherent advantage of btrfs or something that
other mainstream filesystems (ext3, ext4) will be able to adopt as well ?

I have a nother question please. Ppl say the the current filesystems
(ext3, maybe even
ext4) are not scalable. I guess they say that because fsck is already
too slow,  and
disks are always getting bigger... Is that the only scalability
problem of the current fs's ?

With respect to the scalability probs of the current fs's, is btrfs
inherently better ?
I guess it naturally eliminates the fsck problem, because of the COW /
"everything is
a snapshot" ideas. But are there more inherent advantages that will
lead to better
scaling ?

Thank you very much for answering !
Voni