I create a new BTrFS raid10 file system using two 250GB drives and the second partition on a third 80GB drive. I create a subvol and snapshot. I mount the snapshot and start copying 8GB of data to it. It gets to around 1GB and the Desktop disappears and what looks like a non interactive terminal comes up with dump/crash information. I don't have a camera handy or I'd take a picture and post it. It basically looks like stack trace info. CTRL-ALT F7 will eventually bring back the Desktop though but the entire BTrFS portion of the OS is hung and non responsive until I reboot.

I've reformated and reproduced this problem 3 times now and I'm about to give up :(

I realize it is possible this problem is not entirely BTrFS' fault because I'm on natty which is still alpha.

More granular details in case I'm an idiot:

1) Create FS:
sudo mkfs.btrfs -m raid10 -d raid10 /dev/sda2 /dev/sdb /dev/sdc

2) Initial temporary mount:
mkdir /btrfs && sudo mount -t btrfs /dev/sda2 /btrfs

3) Create subvol
btrfs s c /btrfs/vm

4) Create initial snapshot: (optional)
btrfs s sn /btrfs/cantremember.snap.something

5)unmount /btrfs and mount /btrfs/vm
sudo mount -t btrfs -o subvol=vm /dev/sda2 /btrfs/vm

6) Copy data to subvolume.
7) Balance data across drives: (optional)
btrfs f bal <path>

(never get to this step 7...) Am I doing something wrong?