Difference between revisions of "Talk:BTRFS Fun"

Revision as of 03:44, 26 May 2011

About this section :

http://docs.funtoo.org/index.php?title=BTRFS_Fun&curid=14792&diff=17917&oldid=17916#Deploying_a_Funtoo_instance_in_a_subvolume_other_than_0_.28should_avoid_the_rsync.29

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
# btrfs 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 :

@subvolid=0
   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.