.. highlight:: sh

Preparation
======================

.. contents:: Table of Contents
   :local:

#. Disable Secure Boot. ZFS modules can not be loaded if Secure Boot is enabled.
#. Download a variant of `Rocky Linux 8.4 Live
   ISO <https://dl.rockylinux.org/pub/rocky/8.4/Live/x86_64/>`__ and boot from it.

#. Set root password or ``/root/authorized_keys``.
#. Start SSH server::

    echo PermitRootLogin yes >> /etc/ssh/sshd_config
    systemctl restart sshd

#. Connect from another computer::

    ssh root@192.168.1.19

#. Temporarily set SELinux to permissive in live environment::

    setenforce 0

   SELinux will be enabled on the installed system.

#. Optional: If mirror speed is slow, you can manually pick a fixed mirror
   from `mirrorlist <https://mirrors.rockylinux.org/mirrormanager/mirrors>`__
   and apply it::

    sed -i 's|^mirrorlist=|#mirrorlist=|g' /etc/yum.repos.d/*
    sed -i 's|^#baseurl=|baseurl=|g' /etc/yum.repos.d/*
    sed -i 's|dl.rockylinux.org/$contentdir|mirrors.sjtug.sjtu.edu.cn/rocky|g' /etc/yum.repos.d/*

#. Add ZFS repo::

    source /etc/os-release
    RHEL_ZFS_REPO=https://zfsonlinux.org/epel/zfs-release.el${VERSION_ID/./_}.noarch.rpm
    dnf install -y $RHEL_ZFS_REPO

#. Install ZFS packages::

    dnf config-manager --disable zfs
    dnf config-manager --enable zfs-kmod
    dnf install -y epel-release
    dnf install -y zfs

#. Load kernel modules::

    modprobe zfs

#. Install helper script and partition tool::

    rpm -ivh --nodeps https://dl.fedoraproject.org/pub/fedora/linux/releases/34/Everything/x86_64/os/Packages/a/arch-install-scripts-23-3.fc34.noarch.rpm
    dnf install -y gdisk dosfstools

#. Set RHEL version::

    INST_RHEL_VER=8

#. 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)

#. Identify this installation in ZFS filesystem path::

    INST_ID=rhel

#. Target disk

   List available disks with::

    ls /dev/disk/by-id/*

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

   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'

#. Choose a primary disk. This disk will be used
   for primary EFI partition, default to
   first disk in the array::

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

#. 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 <https://www.delphix.com/blog/delphix-engineering/zfs-raidz-stripe-width-or-how-i-learned-stop-worrying-and-love-raidz>`__
   and `here <https://docs.google.com/spreadsheets/d/1tf4qx1aMJp8Lo_R6gpT689wTjHv6CGVElrPqTA0w_ZY/>`__.

   Refer to `zpoolconcepts <https://openzfs.github.io/openzfs-docs/man/7/zpoolconcepts.7.html>`__
   and `zpool-create <https://openzfs.github.io/openzfs-docs/man/8/zpool-create.8.html>`__
   man pages for details.

#. Set partition size:

   Set ESP size::

    INST_PARTSIZE_ESP=2 # in GB

   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 <https://chrisdown.name/2018/01/02/in-defence-of-swap.html>`__
   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=