# Provisioning

After flashing the Alpine Linux extended ISO, partition the disks. For this action internet is required since `zfs` and `sgdisk` are not included on the extended ISO, therefore it needs to be obtained from the repository.

To set it up `setup-interfaces` and `setup-apkrepos` will be used.

```
# setup-interfaces -ar
# setup-apkrepos -c1
```

A few packages will have to be installed first:

```
# apk add zfs lsblk sgdisk wipefs dosfstools acpid mdadm
```

and load the ZFS kernel module

```
# modprobe zfs
```

Define the disks you want to use for this install

```
# export disks="/dev/disk/by-id/<id-disk-1> ... /dev/disk/by-id/<id-disk-n>"
```

with `<id-disk-n>` for $n \in \mathbb{N}$ the `id` of the disk. 

> According to [openzfs-FAQ](https://openzfs.github.io/openzfs-docs/Project%20and%20Community/FAQ.html) using `/dev/disk/by-id/` is the best practice for small pools. For larger pools, using serial Attached SCSI (SAS) and the like, see [vdev_id](https://openzfs.github.io/openzfs-docs/man/master/5/vdev_id.conf.5.html) for proper configuration. 

Wipe the existing disk partitions

```
# for disk in $disks; do
> zpool labelclear -f $disk
> wipefs -a $disk
> sgdisk --zap-all $disk
> done
```

Create on each disk an `EFI system` partition (ESP) and a `Linux filesystem` partition

```
# for disk in $disks; do
> sgdisk -n 1:1m:+512m -t 1:ef00 $disk
> sgdisk -n 2:0:-10m -t 2:8300 $disk
> done
```

Create device nodes

```
# mdev -s
```

Define the EFI partitions

```
# export efiparts=""
# for disk in $disks; do
> efipart=${disk}-part-1
> efiparts="$efiparts $efipart"
> done
```

Create a `mdraid` array on the EFI partitions

```
# modprobe raid1
# mdadm --create --level 1 --metadata 1.0 --raid-devices <n> /dev/md/esp $efiparts
# mdadm --assemble --scan
```

Format the array with a FAT32 filesystem

```
# mkfs.fat -F 32 /dev/md/esp
```

## ZFS pool creation

Define the pool partitions

```
# export poolparts=""
# for disk in $disks; do
> poolpart=${disk}-part-2
> poolparts="$poolparts $poolpart"
> done
```

Create the system pool

```
# zpool create -f \
    -o ashift=12 \
    -O compression=lz4 \
    -O acltype=posix \ 
    -O xattr=sa \
    -O dnodesize=auto \
    -m none \
    tank raidz1 $poolparts
```

> Additionally, the `spare` option can be used to indicate spare disks. If more redundancy is preferred than `raidz2` and `raidz3` are possible [alternatives](https://openzfs.github.io/openzfs-docs/man/master/7/zpoolconcepts.7.html) for `raidz1`. If a single disk is used the `raidz` option can be left aside. For further information see [zpool-create](https://openzfs.github.io/openzfs-docs/man/master/8/zpool-create.8.html). 

Then create the system datasets 

```
# zfs create -o mountpoint=none tank/root
# zfs create -o canmount=noauto -o mountpoint=/ -o atime=off -o quota=24g tank/root/alpine
# zfs create -o mountpoint=/home -o atime=off -o setuid=off -o devices=off -o quota=<home-quota> -o encryption=on -o keyformat=passphrase tank/home
# zfs create -o mountpoint=/var -o exec=off -o setuid=off -o devices=off -o quota=16g tank/var
```

> Setting the `<home-quota>` depends on the total size of the pool, generally try to reserve some empty space in the pool.

Finally, export the zpool

```
# zpool export tank
```