[arch-general] BTRFS integration

[C Anthony Risinger]

> my main issue is that btrfs is advanced and we have much to think
> about the way we want to include it.  rollback support and friends are
> very cool (this just saved me the other day actually) and i think
> would provide a great benefit to the arch rolling model.

additionally its not as simple as other FS's.  the subvolume/pooling
aspect of btrfs means that if you wanted your /var to be compressed,
your /home to be (insert mount options), and your root to be (insert
mount options), all RAID10 across 4 devices... you would mkfs.btrfs
ONCE, then create individual subvols for each.  methinks w/o looking
at AIF code that this is rather exotic compared to the
partition-per-FS options currently available.

i just think it's a good idea to start thinking about and integrating
all of this now, as btrfs is evolving rapidly and there is a
tremendous amount of community interest in it across all distros.

btrfs was merged at .29, declared ready for early adopters in .32, and
gaining interesting features + stability all the time.  i believe it
will be "declared stable" sooner than some may think.

and rollback is super useful, and would be a natural addition to the
Arch's rolling model... afiak the Fedora 13 rollback is mostly
useless; the hook i have created is more featureful, which makes Arch
the only distro truly supporting btrfs rollbacks :-) (not OOTB
however...)

C Anthony