About this section :
Can I rewrite it, because it's clear that you don't understand what DestroyFx and I are trying to explain to you.
- fdisk /dev/sda2
- mkfs.btrfs /dev/sda2
- mount /dev/sda2 /mnt/funtoo
- subvolume create /mnt/funtoo /mnt/funtoo/live-vfs-root-20110523
- chroot /mnt/funtoo/live-vfs-root-20110523 /bin/bash
That cannot work for sure, since you have formatted the /mnt/funtoo and you try to chroot on an empty partition.
And about this :
Mount to the no named volume somewhere (e.g. mount -o subvolid=0 /dev/sdX /mnt)
Take a snapshot (remember to check its identification number) of your current subvolume and store it under the non named volume you just have just mounted (btrfs snapshot create / /mnt/before-updating-20110524) -- (Where is the "frontier"? If 0 is monted does its contennts also appear in the taken snashot located on the same volume?)
I'm gonna explain it in my own words.
If you mount -o subvolid=0 /dev/sdx /mnt
When you enter /mnt, you will be able to snapshot whatever subvolume that you want.
So, if you have this :
subvolume home subvolume root a snapshot
If you run this : btrfs subvolume snapshot / test, you will end with :
subvolume home subvolume root a snapshot test
Test will contains the data from all the subvolume under the subvolid=0.
But if you run this and you didn't run the first snapshot command :
btrfs subvolume snapshot home test_test, you will end with : @subvolid=0
subvolume home subvolume root a snapshot test_test
test_test will contains only the data from home.
When you mount the subvolid=0, you should never use the / to snapshot, but you should use a specific subvolume instead. That's a BTRFS feature, it's like Logicial Partition inside the Virtual Group stuff if you refer to LVM.
I can even post my suggestion here and you will be free to include them or not inside the page.