Configure FreeBSD AWS ZFS ZMI

zfs_ami.sh

#!/bin/sh
# adapted from https://www.daemonology.net/blog/2019-02-16-FreeBSD-ZFS-AMIs-now-available.html

mdconfig -a -t swap -s 3G -u 2
newfs /dev/md2
mkdir /mdisk
mount /dev/md2 /mdisk
tar -czf /mdisk/base.txz --exclude .snap -C /mnt .
umount /mnt

gpart destroy -F nda0
dd if=/dev/zero bs=1m of=/dev/nda0
gpart create -s gpt nda0
gpart add -a 4k -s 40M -t efi nda0
newfs_msdos -F 32 -c 1 /dev/nda0p1
mount -t msdosfs -o longnames /dev/nda0p1 /mnt
mkdir -p /mnt/EFI/BOOT
cp /boot/loader.efi /mnt/EFI/BOOT/BOOTX64.efi
umount /mnt
gpart add -a 1m -t freebsd-zfs -l disk0 nda0

zpool create -o altroot=/mnt -O compress=lz4 -O atime=off -m none -f zroot nda0p2
zfs create -o mountpoint=none zroot/ROOT
zfs create -o mountpoint=/ -o canmount=noauto zroot/ROOT/default
mount -t zfs zroot/ROOT/default /mnt
zfs create -o mountpoint=/tmp -o exec=on -o setuid=off zroot/tmp
zfs create -o mountpoint=/usr -o canmount=off zroot/usr
zfs create zroot/usr/home
zfs create -o setuid=off zroot/usr/ports
zfs create zroot/usr/src
zfs create -o mountpoint=/var -o canmount=off zroot/var
zfs create -o exec=off -o setuid=off zroot/var/audit
zfs create -o exec=off -o setuid=off zroot/var/crash
zfs create -o exec=off -o setuid=off zroot/var/log
zfs create -o atime=on zroot/var/mail
zfs create -o setuid=off zroot/var/tmp
zpool set bootfs=zroot/ROOT/default zroot

tar -xf /mdisk/base.txz -C /mnt

: > /mnt/etc/fstab
echo 'zfs_load="YES"' >> /mnt/boot/loader.conf
echo 'kern.geom.label.disk_ident.enable="0"' >> /mnt/boot/loader.conf
echo 'kern.geom.label.gptid.enable="0"' >> /mnt/boot/loader.conf
echo 'vfs.zfs.min_auto_ashift=12' >> /mnt/etc/sysctl.conf
echo 'zfs_enable="YES"' >> /mnt/etc/rc.conf

zfs umount -a

# mkami "FreeBSD 13.1-RELEASE-amd64 ZFS" "FreeBSD/amd64 ZFS 13.1-RELEASE"