btrfs记录

dd if=/dev/zero of=./btrfs_a.img bs=1M count=100
dd if=/dev/zero of=./btrfs_b.img bs=1M count=100
sudo losetup /dev/loop7 btrfs_a.img
sudo losetup /dev/loop6 btrfs_b.img
sudo mkfs.btrfs -L mybtrfs /dev/loop7
mkdir /tmp/btrfs
sudo mount -t btrfs /dev/loop7 /tmp/btrfs
sudo mount btrfs subvolume create /tmp/btrfs/myvol
sudo mount -t btrfs -o subvol=myvol /dev/loop7 /tmp/myvol
sudo btrfs dev add /dev/loop6 ./mybtrfs/
sudo btrfs fi show /dev/loop6
mount -o remount,compress=lzo,space_cache,autodefrag /dev/sdaX /mnt
mkdir -p /mnt/rootfs/home /mnt/rootfs/var/cache/pacman/pkg /mnt/rootfs/dev /mnt/rootfs/proc /mnt/rootfs/sys
mkdir -p /mnt/rootfs/var/cache/pacman/pkg
mount -o subvol=homefs,compress=lzo,space_cache,autodefrag /dev/sdaX /mnt/rootfs/home
mount -o subvol=pkg,compress=lzo,space_cache,autodefrag /dev/sdaX /mnt/rootfs/var/cache/pacman/pkg
mount -o subvolid=0 /dev/sdaX /mnt
http://tieba.baidu.com/p/1802765870
http://www.funtoo.org/wiki/BTRFS_Fun