Table of Contents

Installing FreeBSD Root on ZFS using GPT

Manually Installing FreeBSD on ZFS

This guide assumes you want to manually creating the pool, to change default settings, or to not use the entire disk. If you just want to setup ZFS on the entire disk, use the 'ZFS' option in the bsdinstall partitioning menu.

  1. Boot FreeBSD install DVD or USB Memstick
  1. Select Install, and answer questions such as keyboard layout and hostname
  1. When prompted to partition the disk:
    1. If you do not want to use the entire disk, skip to the Partition Creation section.
    2. choose the 'shell' option. In this mode you are expected to create a root file system mounted under /mnt that the installer will install the operating system into.
    3. Determine which disk you wish to use:
camcontrol devlist

<TOSHIBA HDWN180 GX2M> at scbus7 target 0 lun 0 (ada0,pass1)

SATA disks usually start with ada followed by a number. SAS and USB disks start with da followed by a number. The rest of this page assumes the disk is ada0; replace it with your disk device's name in all commands below.

  1. Create a fresh partition table:
gpart destroy ada0
gpart create -s gpt ada0
This will erase all data on the disk!
  1. Create the bootcode partition:
    1. for UEFI Boot:
gpart add -a 4k -s 260M -t efi ada0
# Create a FAT32 partition
newfs_msdos -F 32 -c 1 /dev/ada0p1
mount -t msdosfs -o longnames /dev/ada0p1 /mnt
mkdir -p /mnt/EFI/BOOT
cp /boot/loader.efi /mnt/EFI/BOOT/BOOTX64.efi
umount /mnt
  1. for Legacy Boot:
gpart add -a 4k -s 512K -t freebsd-boot ada0
gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada0

Create Partitions

Add some partitions for FreeBSD to use: a freebsd-swap partition and a freebsd-zfs partition.

Create the swap and zfs partitions 

gpart add -a 1m -s 4G -t freebsd-swap -l swap0 ada0
gpart add -a 1m -t freebsd-zfs -l disk0 ada0
Note: While a ZFS Swap Volume can be used instead of the freebsd-swap partition, it is not recommended, and crash dumps can't be saved to the ZFS Swap Volume.

Create the Pool

  1. Find the device for the freebsd-zfs partition created above
gpart show -p ada0

⇒ 40 15628053088 ada0 GPT (7.3T) 40 1024 ada0p1 freebsd-boot (512K) 1064 984 - free - (492K) 2048 4194304 ada0p2 freebsd-swap (2.0G) 4196352 15623856776 ada0p3 freebsd-zfs (7.3T)

  1. Mount a tmpfs to /mnt
mount -t tmpfs tmpfs /mnt
  1. Create the ZFS Pool
zpool create -o altroot=/mnt zroot ada0p3
Note: zroot is the name of the ZFS Pool; it could be anything, e.g. tank, data, mypool, …

Create the ZFS file system hierarchy

The lz4 compression algorithm is fast enough to be used by default, even for incompressible data. 

zfs set compress=on						zroot

Create a Boot Environment hierarchy 

zfs create -o mountpoint=none					zroot/ROOT
zfs create -o mountpoint=none					zroot/ROOT/default
mount -t zfs zroot/ROOT/default /mnt

Create the rest of the filesystems. 

zfs create -o mountpoint=/tmp	-o exec=on	-o setuid=off	zroot/tmp
zfs create -o canmount=off -o mountpoint=/usr			zroot/usr
zfs create							zroot/usr/home
zfs create 			-o exec=off	-o setuid=off	zroot/usr/src
zfs create 							zroot/usr/obj
zfs create -o mountpoint=/usr/ports		-o setuid=off	zroot/usr/ports
zfs create 			-o exec=off	-o setuid=off	zroot/usr/ports/distfiles
zfs create 			-o exec=off	-o setuid=off	zroot/usr/ports/packages
zfs create -o canmount=off -o mountpoint=/var			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		-o exec=off	-o setuid=off	zroot/var/mail
zfs create 			-o exec=on	-o setuid=off	zroot/var/tmp

Links and Permissions 

ln -s /usr/home /mnt/home
chmod 1777 /mnt/var/tmp
chmod 1777 /mnt/tmp

Configure Boot Environment

zpool set bootfs=zroot/ROOT/default zroot

Finish install

  1. Create /tmp/bsdinstall_etc/fstab
cat << EOF > /tmp/bsdinstall_etc/fstab
# Device			Mountpoint		FStype	Options		Dump	Pass#
/dev/gpt/swap0			none			swap	sw		0	0
EOF
  1. Exit Shell Partitioning mode, bsdinstall will continue and complete the installation.
exit
  1. In the post installation step, when asked if you would like to drop into the installed system, choose yes and run the following two commands.
sysrc zfs_enable="YES"
echo 'zfs_load="YES"' >> /boot/loader.conf