Preparation

  1. Download 2021.09.01 Live ISO and signature.

  2. Follow installation guide on Arch wiki up to Update the system clock.

  3. Set root password or /root/authorized_keys.

  4. Start SSH server:

    systemctl start sshd
    
  5. Connect from another computer:

    ssh root@192.168.1.19
    

    and, most important, enter a bash shell:

    bash
    

    This guide is untested with the default shell zsh in live environment.

  6. Expand live root filesystem:

    mount -o remount,size=2G /run/archiso/cowspace/
    
  7. Add archzfs repo.

  8. Install zfs-dkms in live environment.

  9. Load zfs kernel module:

    modprobe zfs
    
  10. Kernel variant

    Store the kernel variant in a variable. Available variants in official repo are:

    • linux

    • linux-lts

    • linux-zen

    • linux-hardened

    INST_LINVAR='linux'
    

    linux-hardened does not support hibernation.

  11. Unique pool suffix. ZFS expects pool names to be unique, therefore it’s recommended to create pools with a unique suffix:

    INST_UUID=$(dd if=/dev/urandom bs=1 count=100 2>/dev/null | tr -dc 'a-z0-9' | cut -c-6)
    
  12. Identify this installation in ZFS filesystem path:

    INST_ID=arch
    
  13. Target disk

    List available disks with:

    ls /dev/disk/by-id/*
    

    If using virtio as disk bus, use /dev/disk/by-path/*.

    Declare disk array:

    DISK='/dev/disk/by-id/ata-FOO /dev/disk/by-id/nvme-BAR'
    

    For single disk installation, use:

    DISK='/dev/disk/by-id/disk1'
    
  14. Choose a primary disk. This disk will be used for primary EFI partition and hibernation, default to first disk in the array:

    INST_PRIMARY_DISK=$(echo $DISK | cut -f1 -d\ )
    

    If disk path contains colon :, this disk can not be used for hibernation. encrypt mkinitcpio hook treats : as argument separator without a means to escape this character.

  15. Set vdev topology, possible values are:

    • (not set, single disk or striped; no redundancy)

    • mirror

    • raidz1

    • raidz2

    • raidz3

    INST_VDEV=
    

    This will create a single vdev with the topology of your choice. It is also possible to manually create a pool with multiple vdevs, such as:

    zpool create --options \
          poolName \
          mirror sda sdb \
          raidz2 sdc ... \
          raidz3 sde ... \
          spare  sdf ...
    

    Notice the cost of parity when using RAID-Z. See here and here.

    Refer to zpoolconcepts and zpool-create man pages for details.

  16. Set partition size:

    Set ESP size. ESP contains Live ISO for recovery, as described in optional configurations:

    INST_PARTSIZE_ESP=4 # in GB
    #INST_PARTSIZE_ESP=1 # if local recovery is not needed
    

    Set boot pool size. To avoid running out of space while using boot environments, the minimum is 4GB. Adjust the size if you intend to use multiple kernel/distros:

    INST_PARTSIZE_BPOOL=4
    

    Set swap size. It’s recommended to setup a swap partition. If you intend to use hibernation, the minimum should be no less than RAM size. Skip if swap is not needed:

    INST_PARTSIZE_SWAP=8
    

    Root pool size, use all remaining disk space if not set:

    INST_PARTSIZE_RPOOL=