/grub-btrfs

grub-btrfs, Include btrfs snapshots at boot options. (Grub menu)

Primary LanguageShellGNU General Public License v3.0GPL-3.0

GitHub release

grub-btrfs

This is a version 4.xx of grub-btrfs

BTC donation address: 1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt

Description

Improves Grub by adding "btrfs snapshots" to the Grub menu.

You can start your system on a "snapshot" from the Grub menu.

Supports manual snapshots, snapper, timeshift ...

Warning: booting on read-only snapshots can be tricky

If you choose to do it, /var/log must be on a separate subvolume.

Otherwise, make sure your snapshots are writeable.

See this ticket for more info.

What does grub-btrfs v4.xx do :

  • Automatically List snapshots existing on root partition (btrfs).
  • Automatically Detect if "/boot" is in separate partition.
  • Automatically Detect kernel, initramfs and intel microcode in "/boot" directory on snapshots.
  • Automatically Create corresponding "menuentry" in grub.cfg
  • Automatically detect snapper and use snapper's snapshot description if available.
  • Automatically generate grub.cfg if you use the provided systemd service.

Installation :

Arch Linux

pacman -S grub-btrfs

Manual

  • Run make install or look into Makefile for instructions on where to put each file.

NOTE: Generate your Grub menu after installation for the changes to take effect.

On Arch Linux use grub-mkconfig -o /boot/grub/grub.cfg.

Customization:

You have the possibility to modify many parameters in /etc/default/grub-btrfs/config.

  • GRUB_BTRFS_SUBMENUNAME="Arch Linux Snapshots"

    Name appearing in the Grub menu. Use distribution information from /etc/os-release by default.

  • GRUB_BTRFS_PREFIXENTRY="Snapshot:"

    Add a name ahead your snapshots entries in the Grub menu.

  • GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"

    Show full path snapshot or only name in the Grub menu, weird reaction with snapper.

  • GRUB_BTRFS_TITLE_FORMAT="p/d/n"

    Custom title, shows/hides p"prefix" d"date" n"name" in the Grub menu, separator "/", custom order available.

  • GRUB_BTRFS_LIMIT="50"

    Limit the number of snapshots populated in the GRUB menu.

  • GRUB_BTRFS_SUBVOLUME_SORT="descending"

    Sort the found subvolumes by newest first ("descending") or oldest first ("ascending").

    If "ascending" is chosen then

    the $GRUB_BTRFS_LIMIT oldest subvolumes will populate the menu.

  • GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND="true"

    Show snapshots found during run "grub-mkconfig".

  • GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND="true"

    Show Total number of snapshots found during run "grub-mkconfig".

  • GRUB_BTRFS_NKERNEL=("kernel-custom")

    Use it only if you have a custom kernel name

  • GRUB_BTRFS_NINIT=("initramfs-custom.img" "initrd.img-custom")

    Use it only if you have a custom initramfs name.

  • GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img")

    Use it only if you have custom intel-ucode.

  • GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker")

    Ignore specific path during run "grub-mkconfig".

    For example:

    If path is a directory # Found Snapshot: 2016-03-31 10:24:41 var/lib/docker/btrfs/subvolumes/...

    use : GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker")

    If path is a subvolume : # Found Snapshot: 2016-03-31 10:24:41 @var/lib/docker/btrfs/subvolumes/...

    use : GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@var/lib/docker")

    You can combine them

    use : GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@var/lib/docker" "var/lib/docker")

  • GRUB_BTRFS_SNAPPER_CONFIG="root"

    Snapper's config name to use.

  • GRUB_BTRFS_DISABLE="false"

    Disable grub-btrfs.

  • GRUB_BTRFS_DIRNAME="grub"

    Name of the grub folder in /boot/, might be grub2 on some distributions.

  • GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION="false"

    Change to "true" if you have a boot partition in a different subvolume.

  • GRUB_BTRFS_MKCONFIG=grub-mkconfig

    Name or path of the 'grub-mkconfig' executable; might be 'grub2-mkconfig' on some distributions.

  • Password protection management for submenu (refer to the Grub documentation)

    • GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS=""

      Add authorized usernames separate by comma (foo,bar)

      When Grub's password protection is enabled, the superuser is authorized by default, it isn't necessary to add it

    • GRUB_BTRFS_DISABLE_PROTECTION_SUBMENU="false"

      Disable authentication support for submenu of Grub-btrfs only (--unrestricted)

      doesn't work if GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS isn't empty

Automatically update grub

If you would like Grub to automatically update when a snapshot is made or deleted:

  • Mount your subvolume which contains snapshots to /.snapshots
  • Use systemctl start/enable grub-btrfs.path
  • grub-btrfs.path automatically (re)generates grub.cfg when a modification appears in /.snapshots

Special thanks for assistance and contributions