https://github.com/johnramsden/zedenv-grub
zedenv plugin for GRUB
https://github.com/johnramsden/zedenv-grub
linux python python3 zfs zfsonlinux
Last synced: about 2 months ago
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zedenv plugin for GRUB
- Host: GitHub
- URL: https://github.com/johnramsden/zedenv-grub
- Owner: johnramsden
- License: bsd-3-clause
- Created: 2018-06-04T00:31:50.000Z (about 7 years ago)
- Default Branch: master
- Last Pushed: 2020-02-16T22:40:20.000Z (over 5 years ago)
- Last Synced: 2025-04-02T06:37:23.962Z (2 months ago)
- Topics: linux, python, python3, zfs, zfsonlinux
- Language: Python
- Homepage: https://zedenv.readthedocs.io/en/latest/plugins.html#grub
- Size: 353 KB
- Stars: 11
- Watchers: 4
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.rst
- License: LICENSE
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README
==================
zedenv GRUB Plugin
==================
zedenv - ZFS boot environment manager - GRUB plugin
Install
-------
Install ``zedenv`` then ``zedenv-grub``.
Setup
-----
One of two types of setup needs to be used with grub.
* Boot on ZFS - separate ``grub`` dataset needed.
* Separate partition for kernels
Boot on ZFS (Recommended)
#########################
To use boot on ZFS:
* A ``grub`` dataset is needed. It should be mounted at ``/boot/grub``.
* ``org.zedenv.grub:bootonzfs`` should be set to ``yes``
* Individual boot environments should contain their kernels in ``/boot``, which should be part of the root dataset.
To convert an existing grub install, set up the ``grub`` dataset, and mount it. Then install grub again.
.. code-block:: shell
zfs create -o canmount=off zroot/boot
zfs create -o mountpoint=legacy zroot/boot/grub
mount -t zfs zroot/boot/grub /boot/grub
# efi
mount ${esp} /boot/efi
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=GRUB
# or for BIOS
grub-install --target=i386-pc /dev/sdx --recheck
If you get:
.. code-block:: shell
/dev/sda
Installing for i386-pc platform.
grub-install: error: failed to get canonical path of `/dev/ata-SAMSUNG_SSD_830_Series_S0VVNEAC702110-part2'.
A workaround is to symlink the expected partition to the id
.. code-block:: shell
ln -s /dev/sda2 /dev/ata-SAMSUNG_SSD_830_Series_S0VVNEAC702110-part2
Separate Partition for Kernels
###############################
An example system on Arch Linux with a separate partition for kernels would be the following:
* Boot partition mounted to ``/mnt/boot``.
* The directory containing kernels for the active boot environment, ``/mnt/boot/env/zedenv-${boot_env}`` bind mounted to ``/boot``.
* The grub directory ``/mnt/boot/grub`` bindmounted to ``/boot/grub``
* ``org.zedenv.grub:bootonzfs`` should be set to ``no`` with ``zedenv set org.zedenv.grub:bootonzfs=no``
What this would look like during an arch Linux install would be the following:
.. code-block:: shell
zpool import -d /dev/disk/by-id -R /mnt vault
mkdir -p /mnt/mnt/boot /mnt/boot
mount /dev/sda1 /mnt/mnt/boot
mkdir /mnt/mnt/boot/env/zedenv-default /mnt/boot/grub
mount --bind /mnt/mnt/boot/env/zedenv-default /mnt/boot
mount --bind /mnt/mnt/boot/grub /mnt/boot/grub
genfstab -U -p /mnt >> /mnt/etc/fstab
arch-chroot /mnt /bin/bash
In chroot
.. code-block:: shell
export ZPOOL_VDEV_NAME_PATH=1
grub-install --target=x86_64-efi --efi-directory=/mnt/boot --bootloader-id=GRUB
grub-mkconfig -o /boot/grub/grub.cfg
An example generated grub.cfg looks like:
.. code-block:: shell
### BEGIN /etc/grub.d/10_linux ###
menuentry 'Arch Linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-a1b916c0819a1863' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_gpt
insmod fat
set root='hd0,gpt1'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt1 --hint-efi=hd0,gpt1 --hint-baremetal=ahci0,gpt1 B11F-0328
else
search --no-floppy --fs-uuid --set=root B11F-0328
fi
echo 'Loading Linux linux ...'
linux /env/zedenv-default/vmlinuz-linux root=ZFS=vault/sys/zedenv/ROOT/default rw quiet
echo 'Loading initial ramdisk ...'
initrd /env/zedenv-default/initramfs-linux.img
}
Converting Existing System
~~~~~~~~~~~~~~~~~~~~~~~~~~
Create a backup.
.. code-block:: shell
cp -a /boot /boot.bak
Unmount ``/boot``, and remount it at ``/mnt/boot``.
.. code-block:: shell
mkdir -p /mnt/boot
mount /dev/sdxY /mnt/boot
Then you want to move your current kernel to ``/mnt/boot/env/zedenv-${boot_env_name}``
.. code-block:: shell
mkdir /mnt/boot/env/zedenv-default
mv /mnt/boot/* /mnt/boot/env/zedenv-default
Move the grab directory back if it was also moved (or don't move it in the first place).
.. code-block:: shell
mv /mnt/boot/env/zedenv-default/grub /mnt/boot/grub
Now bindmount the current kernel directory to ``/boot`` so that everything is where the system expects it.
.. code-block:: shell
mount --bind /mnt/boot/env/zedenv-default /boot
Same thing with the grub directory
.. code-block:: shell
mount --bind /mnt/boot/grub /boot/grub
Now everything is back to appearing how it looked originally, but things are actually stored in a different place.
---
You're also probably going to want to update your fstab, if you're using Arch you can use genfstab, which requires ``arch-install-scripts``.
.. code-block:: shell
genfstab -U -p /
You'll need to add the output to ``/etc/fstab.``
This is what an example looks like.
.. code-block:: shell
# /dev/sda1
UUID=B11F-0328 /mnt/boot vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 2
/mnt/boot/env/zedenv-grub-test-3 /boot none rw,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro,bind 0 0
/mnt/boot/grub /boot/grub none rw,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro,bind 0 0
Post Setup
-------------
After install, run ``zedenv --plugins``, you should see ``grub``.
Set bootloader config, options can be queried with ``zedenv get --defaults``:
.. code-block:: shell
$ zedenv get --defaults
PROPERTY DEFAULT DESCRIPTION
org.zedenv:bootloader Set a bootloader plugin.
org.zedenv.systemdboot:esp /mnt/efi Set location for esp.
org.zedenv.grub:boot /mnt/boot Set location for boot.
org.zedenv.grub:bootonzfs yes
Set the bootloader so it doesn't have to be declared on every usage with the ``-b`` flag.
.. code-block:: shell
# zedenv set org.zedenv:bootloader=grub
``zedenv`` will do its best to decide whether or not you are booting off of an all ZFS system, but it can also be set explicitly with ``org.zedenv.grub:bootonzfs=yes``.
Any values you have set explicitly will show up with ``zedenv get``.
Now create a new boot environment:
.. code-block:: shell
# zedenv create linux-4.18.12
# zfs list
NAME USED AVAIL REFER MOUNTPOINT
zroot 2.43G 36.1G 29K none
zroot/ROOT 2.42G 36.1G 29K none
zroot/ROOT/default 2.42G 36.1G 2.42G /
zroot/ROOT/linux-4.18.12 1K 36.1G 2.42G /
zroot/data 9.36M 36.1G 29K none
zroot/data/home 9.33M 36.1G 9.33M legacy
You may want to disable all of the grub generators in ``/etc/grub.d/`` except for ``00_header`` and the zedenv generator ``05_zfs_linux.py`` by removing the executable bit.