Preparation

Download live ISO compatible with ZFS:
1. Check zfs-dkms version
  
  Visit archzfs repo, search for zfs-dkms in page:
```
zfs-dkms-2.1.2-1-x86_64.pkg.tar.zst
```
  Ignore unstable variants such as zfs-dkms-git or zfs-dkms-rc. In this case, version number is 2.1.2, between two -.
2. Check supported kernel version. Plug the version number into the following link:
```
https://github.com/openzfs/zfs/blob/zfs-2.1.2/META
```
  Visit the page, the supported max kernel version is:
```
Linux-Maximum: 5.15
```
3. Visit Arch Linux releases page and download a supported version. Note that minor kernel releases does not affect ZFS compatibility, i. e., both 5.15.5 and 5.15.15 are supported by ZFS with Linux-Maximum: 5.15.
Follow installation guide on Arch wiki up to Update the system clock.
Set root password or /root/.ssh/authorized_keys.
Start SSH server:
```
systemctl start sshd
```
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.

Expand live root filesystem:

mount -o remount,size=2G /run/archiso/cowspace/

Add archzfs repo.
Install zfs-dkms in live environment.
Load zfs kernel module:
```
modprobe zfs
```
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.
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=arch
```
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'
```
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.
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.

For boot pool, which must be readable by GRUB, mirrored vdev should always be used for maximum redundancy. This guide will use mirrored bpool for multi-disk setup.

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