FreeBSD: Semi-manual ZFS+UEFI installation

This post will show how to install and update a FreeBSD ZFS+UEFI installation.

Start the installer normally, and go through the steps. When you get to the part where it asks whether you want to install to UFS, ZFS, etc, chose to open a shell.

Create the partition scheme for each drive you will be using in your root zpool, and make sure to use unique labels. Make sure to replace ‘ada0’ with whatever is appropriate for you.
gpart create -s gpt ada0
gpart add -t efi -s 800k ada0
gpart add -t freebsd-zfs -a 128m -l YourLabel ada0

I aligned the freebsd-zfs partition to 128MiB to ensure it’s 4k aligned, and to leave room for boot loader changes. 

Create the zpool and add datasets, then exit the shell. The datasets for /usr and /var are not mounted, while their child datasets are mounted. This is because most of the data in /usr and /var belongs in the boot environment. Some of the subpaths have their own datasets because they should, in my opinion, be shared among boot environments.

zpool create -m none -o altroot=/mnt -O atime=off -O compress=lz4 sys gpt/YourLabel

zfs create -o canmount=off sys/ROOT
zfs create -o mountpoint=/ -o canmount=noauto sys/ROOT/default
zfs mount sys/ROOT/default
zfs create -o mountpoint=/var -o canmount=off -o compress=gzip-9 -o setuid=off -o exec=off sys/var
zfs create sys/var/audit
zfs create sys/var/log
zfs create -o atime=on sys/var/mail
zfs create -o atime=on sys/var/spool
zfs create -o exec=on sys/var/tmp

zfs create -o mountpoint=/usr -o canmount=off sys/usr
zfs create -o compress=gzip-9 sys/usr/src
zfs create sys/usr/obj

zfs create -o canmount=off sys/data
zfs create -o mountpoint=/usr/home -o setuid=off sys/data/homedirs
zfs create -o mountpoint=/root sys/data/root


zpool set bootfs=sys/ROOT/default sys
exit

Now the installer should continue doing its thing. Do what you’d normally do, but when it asks if you want to open a shell into the new environment, say yes.

Execute this commands to ensure ZFS works as expected:
echo 'opensolaris_load="yes"' >> /boot/loader.conf
echo 'zfs_load="yes" >> /boot/loader.conf
echo 'zfs_enable="YES"' >> /etc/rc.conf

Configure the UEFI partitions by doing the following for each drive that is a member of the ‘sys’ zpool: (remember to replace ‘ada0’ with whatever is appropriate for you)
dd if=/boot/boot1.efifat of=/dev/ada0p1

When upgrading FreeBSD, re-run the above command to apply new bootcode *after* having run installworld.