UEFI#

This guide can be used to install Alpine onto a single disk with with or without ZFS encryption.

It assumes the following:

  • Your system uses UEFI to boot

  • Your system is x86_64

  • You're mildly comfortable with ZFS, EFI and discovering system facts on your own (lsblk, dmesg, gdisk, ...)

Download the latest Alpine Extended ISO, write it to USB drive and boot your system in EFI mode.

Confirm EFI support:

# dmesg | grep -i efivars
[    0.301784] Registered efivars operations

Configure Live Environment#

Source /etc/os-release#

The file /etc/os-release defines variables that describe the running distribution. In particular, the $ID variable defined within can be used as a short name for the filesystem that will hold this installation.

source /etc/os-release
export ID

Configure Networking#

setup-interfaces -r

Add package repositories#

cat <<EOF > /etc/apk/repositories
http://dl-cdn.alpinelinux.org/alpine/latest-stable/main/
https://dl-cdn.alpinelinux.org/alpine/latest-stable/main/
EOF
apk update

Setup additional tools#

apk add zfs zfs-scripts sgdisk wipefs
modprobe zfs

Generate /etc/hostid#

zgenhostid -f 0x00bab10c

Define disk variables#

For convenience and to reduce the likelihood of errors, set environment variables that refer to the devices that will be configured during the setup.

For many users, it is most convenient to place boot files (i.e., ZFSBootMenu and any loader responsible for launching it) on the the same disk that will hold the ZFS pool. However, some users may wish to dedicate an entire disk to the ZFS pool or create a multi-disk pool. A USB flash drive provides a convenient location for the boot partition. Fortunately, this alternative configuration is easily realized by simply defining a few environment variables differently.

Verify your target disk devices with lsblk. /dev/sda, /dev/sdb and /dev/nvme0n1 used below are examples.

First, define variables that refer to the disk and partition number that will hold boot files:

export BOOT_DISK="/dev/sda"
export BOOT_PART="1"
export BOOT_DEVICE="${BOOT_DISK}${BOOT_PART}"

Next, define variables that refer to the disk and partition number that will hold the ZFS pool:

export POOL_DISK="/dev/sda"
export POOL_PART="2"
export POOL_DEVICE="${POOL_DISK}${POOL_PART}"

Disk preparation#

Wipe partitions#

zpool labelclear -f "$POOL_DISK"

wipefs -a "$POOL_DISK"
wipefs -a "$BOOT_DISK"

sgdisk --zap-all "$POOL_DISK"
sgdisk --zap-all "$BOOT_DISK"

Create EFI boot partition#

sgdisk -n "${BOOT_PART}:1m:+512m" -t "${BOOT_PART}:ef00" "$BOOT_DISK"

Create zpool partition#

sgdisk -n "${POOL_PART}:0:-10m" -t "${POOL_PART}:bf00" "$POOL_DISK"

Rescan Device Nodes#

mdev -s

ZFS pool creation#

Create the zpool#

zpool create -f -o ashift=12 \
 -O compression=lz4 \
 -O acltype=posixacl \
 -O xattr=sa \
 -O relatime=on \
 -o autotrim=on \
 -o compatibility=openzfs-2.1-linux \
 -m none zroot "$POOL_DEVICE"

Note

The option -o compatibility=openzfs-2.1-linux is a conservative choice. It can be omitted or otherwise adjusted to match your specific system needs.

Binary releases of ZFSBootMenu are generally built with the latest stable release of ZFS. Future releases of ZFSBootMenu may therefore support newer feature sets. Check project release notes prior to updating or removing compatibility options and upgrading your system pool.

Create initial file systems#

zfs create -o mountpoint=none zroot/ROOT
zfs create -o mountpoint=/ -o canmount=noauto zroot/ROOT/${ID}
zfs create -o mountpoint=/home zroot/home

zpool set bootfs=zroot/ROOT/${ID} zroot

Note

It is important to set the property canmount=noauto on any file systems with mountpoint=/ (that is, on any additional boot environments you create). Without this property, the OS will attempt to automount all ZFS file systems and fail when multiple file systems attempt to mount at /; this will prevent your system from booting. Automatic mounting of / is not required because the root file system is explicitly mounted in the boot process.

Also note that, unlike many ZFS properties, canmount is not inheritable. Therefore, setting canmount=noauto on zroot/ROOT is not sufficient, as any subsequent boot environments you create will default to canmount=on. It is necessary to explicitly set the canmount=noauto on every boot environment you create.

Export, then re-import with a temporary mountpoint of /mnt#

zpool export zroot
zpool import -N -R /mnt zroot
zfs mount zroot/ROOT/${ID}
zfs mount zroot/home

Verify that everything is mounted correctly#

# mount | grep mnt
zroot/ROOT/alpine on /mnt type zfs (rw,relatime,xattr,posixacl)
zroot/home on /mnt/home type zfs (rw,relatime,xattr,posixacl)

Install Alpine#

apk --arch x86_64 -X http://dl-cdn.alpinelinux.org/alpine/latest-stable/main \
 -U --allow-untrusted --root /mnt --initdb add alpine-base

Copy our files into the new install#

cp /etc/hostid /mnt/etc
cp /etc/resolv.conf /mnt/etc
cp /etc/apk/repositories /mnt/etc/apk
cp /etc/network/interfaces /mnt/etc/network

Chroot into the new OS#

mount --rbind /dev /mnt/dev
mount --rbind /sys /mnt/sys
mount --rbind /proc /mnt/proc
chroot /mnt

Set a root password#

passwd

Enable startup targets#

rc-update add hwdrivers sysinit
rc-update add networking
rc-update add hostname

ZFS Configuration#

Install ZFS#

apk add zfs zfs-lts
rc-update add zfs-import sysinit
rc-update add zfs-mount sysinit

Configure mkinitfs to load ZFS support#

echo "/etc/hostid" >> /etc/mkinitfs/features.d/zfshost.files
echo 'features="ata base keymap kms mmc scsi usb virtio zfs zfshost"' > /etc/mkinitfs/mkinitfs.conf

Regenerate initramfs#

mkinitfs -c /etc/mkinitfs/mkinitfs.conf "$(ls /lib/modules)"

Install and configure ZFSBootMenu#

Set ZFSBootMenu properties on datasets#

Assign command-line arguments to be used when booting the final kernel. Because ZFS properties are inherited, assign the common properties to the ROOT dataset so all children will inherit common arguments by default.

zfs set org.zfsbootmenu:commandline="quiet" zroot/ROOT

Create a vfat filesystem#

mkfs.vfat -F32 "$BOOT_DEVICE"

Create an fstab entry and mount#

cat << EOF >> /etc/fstab
$BOOT_DEVICE /boot/efi vfat defaults 0 0
EOF

mkdir -p /boot/efi
mount /boot/efi

Install ZFSBootMenu#

apk add curl

Fetch a prebuilt ZFSBootMenu EFI executable, saving it to the EFI system partition:

mkdir -p /boot/efi/EFI/ZBM
curl -o /boot/efi/EFI/ZBM/VMLINUZ.EFI -L https://get.zfsbootmenu.org/efi
cp /boot/efi/EFI/ZBM/VMLINUZ.EFI /boot/efi/EFI/ZBM/VMLINUZ-BACKUP.EFI

Configure EFI boot entries#

apk add efibootmgr
efibootmgr -c -d "$BOOT_DISK" -p "$BOOT_PART" \
  -L "ZFSBootMenu (Backup)" \
  -l '\EFI\ZBM\VMLINUZ-BACKUP.EFI'

efibootmgr -c -d "$BOOT_DISK" -p "$BOOT_PART" \
  -L "ZFSBootMenu" \
  -l '\EFI\ZBM\VMLINUZ.EFI'

See also

Some systems can have issues with EFI boot entries. If you reboot and do not see the above entries in your EFI selection screen (usually accessible through an F key during POST), you might need to use a well-known EFI file name. See Portable EFI for help with this. Your existing ESP can be used, in place of an external USB drive.

Refer to zbm-kcl.8 and zfsbootmenu.7 for details on configuring the boot-time behavior of ZFSBootMenu.

Prepare for first boot#

Exit the chroot, unmount everything#

exit
cut -f2 -d" " /proc/mounts | grep ^/mnt | tac | while read i; do umount -l $i; done

Export the zpool and reboot#

zpool export zroot
reboot