Background

• based on boot_btrfs_subvol (prototype 0.8)

• create very simple and fast btrfs subvolume snapshot boot environments

Benefits of Goal Setting

• contrary to the linear rw snapshots under zfs (zfs clone), btrfs can create/delete nested snapshots (subvolume snapshots)

WARNING

• dependents on the kernel version, btrfs-tools version, bugfixes and the use of serious functions such as balance, raid5, compression, etc. can delete the complex structures under some circumstances lead to data loss

Dependencies

• Linux (Debian)

  • machine with btrfs

    • (create manually a /ROOT subvolume with "btrfs subvolume create /ROOT")

  • dialog

Features

• create root subvolume snapshot and grub entry

• create nested subvolume snapshot environments

  • current support: 2 layer = 1 (ROOT/subvolume) + 1 (ROOT/subvolume/SUBROOT/subvolume)

Platform

• Linux (Debian 7/Wheezy)

  • ! it is strongly recommended to use kernel 3.16 from wheezy-backports !

• Linux (Debian 8/Jessie)

  • recommended

• Linux (Debian 9/Stretch/Testing)

  • recommended

Usage

    WARNING: subvolboot2 is highly experimental and its not ready for production. Do it at your own risk.
    Current Support: 2 layer (1 ROOT/subvolume + 1 ROOT/subvolume/SUBROOT/subvolume)

    # usage: ./subvolboot2.sh { create | delete | clean-up | create-nested }

Diagram

• boot_btrfs_subvol (prototype 0.8)

• boot_btrfs_nested_subvol (prototype > 0.8)

Screencast

• btrfs / luks / lvm setup

Errata

• 14.02.2015 - !!! - can't delete SUBROOT subvolumes reasonable
• 14.02.2015 - !!! - under certain circumstances can't parse all custom grub entries
• 12.02.2015 - !!! - "delete" function for nested-subvolume works in parent dataset environments only
• 12.02.2015 - need lvm (logical volume) name "-system" (FIXED)
• 11.02.2015 - parsing error after minute swap (FIXED)