Table of Contents

Installing FreeBSD Root on ZFS using UFS /boot

Creating a bootable ZFS Filesystem

  1. Boot FreeBSD install DVD or USB Memstick
  1. Choose Fixit option in sysinstall
  1. Create MBR disk

If you are installing on an New drive, you will need to create the MBR geometry first: 

Fixit# gpart create -s mbr ad0
  1. Create Slice using gpart

This example already has two slices defined on the drive. 

Fixit# gpart show ad0
=>       63  625142385  ad0  MBR  (289G)
         63  209712447    1  !7  (100G)
  209712510     417690    2  !136  (204M)
  210130200  415012248       - free -  (198G)

Create a third slice using the size parameter. You may omit the size to use the remainder of the disk. Then create a BSD partition table on the new slice. 

Fixit# gpart add -s 198G -t freebsd ad0
ad0s3 added
Fixit# gpart create -s BSD ad0s3
ad0s3 created

And examine the result: 

Fixit# gpart show ad0
=>       63  625142385  ad0  MBR  (289G)
         63  209712447    1  !7  (100G)
  209712510     417690    2  !136  (204M)
  210130200  415012248    3  freebsd  (198G)
Note:

Sizes and offsets are specified in sectors (1 sector is typically 512 bytes) but can also be specified in MB or GB by adding a 'M' or 'G' suffix.

  1. Set partition active (Optional)

Some BIOSes might require setting a Slice active. Here we set partition 1 (the Windows Partiton) as the active partition. 

Fixit# gpart set -a active -i 1 ad0
  1. Create partitions (ad0s3a, ad0s3b, ad0s3d)
Fixit# gpart show ad0s3
=>        0  415012248  ad0s3  BSD  (198G)
          0  415012248  ad0s3  - free -  (198G)
Fixit# gpart add -s 1G -t freebsd-ufs ad0s3
ad0s3a added
Fixit# gpart show ad0s3
=>        0  415012248  ad0s3  BSD  (198G)
          0    2097152      1  freebsd-ufs  (1G)
    2097152  412915096         - free -  (197G)
Fixit# gpart add -s 4G -t freebsd-swap ad0s3
ad0s3b added
Fixit# gpart show ad0s3
=>        0  415012248  ad0s3  BSD  (198G)
          0    2097152      1  freebsd-ufs  (1.0G)
    2097152    8380827      2  freebsd-swap  (4.0G)
   10477979  404534269         - free -  (193G)
Fixit# gpart add -t freebsd-zfs ad0s3
ad0s3a added
Fixit# gpart show ad0s3
=>        0  415012248  ad0s3  BSD  (198G)
          0    2097152      1  freebsd-ufs  (1.0G)
    2097152    8380827      2  freebsd-swap  (4.0G)
   10477979  404534269      4  freebsd-zfs  (193G)
Note:
  1. While a ZFS Swap Volume can be used instead of the freebsd-swap partition, crash dumps can't be created on the ZFS Swap Volume.
  2. Sizes and offsets are specified in sectors (1 sector is typically 512 bytes) but can also be specified in MB and GB by using a 'M' or 'G' suffix.
  1. Install boot Manager
Fixit# gpart bootcode -b /mnt2/boot/boot0 ad0
bootcode written to ad0

It's ok if you get an “unknown class” message here, but it you get “failed to install” or the like, you'll need to try again after making sure that nothing is mounted from /dev/ad0. 

Fixit# gpart bootcode -b /mnt2/boot/boot ad0s3
bootcode written to ad0s3

This may fail with an “operation not permitted” error message, since the kernel likes to protect critical parts of the disk. If this happens for you, run: 

Fixit# sysctl kern.geom.debugflags=0x10
  1. Load ZFS kernel module
Fixit# kldload /mnt2/boot/kernel/opensolaris.ko
Fixit# kldload /mnt2/boot/kernel/zfs.ko
  1. Create ZFS Pool zroot
Fixit# mkdir /boot/zfs
Fixit# zpool create zroot /dev/ad0s3d
Fixit# zpool set bootfs=zroot zroot
Note:

zroot is the name of the ZFS Pool, it could be anything (i.e. tank, data, …)

  1. Create UFS /boot
Fixit# mkdir /zroot/bootdir
Fixit# newfs /dev/ad0s3a
Fixit# mount /dev/ad0s3a /zroot/bootdir

Installing FreeBSD to the ZFS filesystem

  1. Create ZFS filesystem hierarchy

The fletcher4 algorithm should be more robust than the fletcher2 algorithm. 

Fixit# zfs set checksum=fletcher4					zroot
Fixit# zfs create -o compression=on	-o exec=on	-o setuid=off	zroot/tmp
Fixit# chmod 1777 /zroot/tmp
Fixit# zfs create							zroot/usr
Fixit# zfs create							zroot/usr/home
Fixit# cd /zroot ; ln -s /usr/home home
Fixit# zfs create -o compression=lzjb 			-o setuid=off	zroot/usr/ports
Fixit# zfs create -o compression=off	-o exec=off	-o setuid=off	zroot/usr/ports/distfiles
Fixit# zfs create -o compression=off	-o exec=off	-o setuid=off	zroot/usr/ports/packages
Note:

If you use nullfs or nfs to mount /usr/ports to different locations/servers, you will also need to nullfs/nfs mount /usr/ports/distfiles and/or /usr/ports/packages. 

Fixit# zfs create -o compression=lzjb 	-o exec=off	-o setuid=off	zroot/usr/src
Fixit# zfs create							zroot/var
Fixit# zfs create -o compression=lzjb 	-o exec=off	-o setuid=off	zroot/var/crash
Fixit# zfs create			-o exec=off	-o setuid=off	zroot/var/db
Fixit# zfs create -o compression=lzjb 	-o exec=on	-o setuid=off	zroot/var/db/pkg
Fixit# zfs create			-o exec=off	-o setuid=off	zroot/var/empty
Fixit# zfs create -o compression=lzjb 	-o exec=off	-o setuid=off	zroot/var/log
Fixit# zfs create -o compression=gzip 	-o exec=off	-o setuid=off	zroot/var/mail
Fixit# zfs create			-o exec=off	-o setuid=off	zroot/var/run
Fixit# zfs create -o compression=lzjb 	-o exec=on	-o setuid=off	zroot/var/tmp
Fixit# chmod 1777 /zroot/var/tmp
Note:
  1. Compression may be set to on, off, lzjb, gzip, gzip-N (where N is an integer from 1 (fastest) to 9 (best compression ratio. gzip is equivalent to gzip-6).
  2. Compression will cause some latency when accessing files on the ZFS filesystems. Use compression on ZFS filesystems which will not be accessed that often.
  1. Install FreeBSD to zroot
Fixit# cd /dist/8.0-*
Fixit# export DESTDIR=/zroot
Fixit# for dir in base catpages dict doc games info lib32 manpages ports; \
  do (cd $dir ; ./install.sh) ; done
Fixit# cd src ; ./install.sh all
Fixit# cd ../kernels ; ./install.sh generic
Fixit# cd /zroot/boot ; cp -Rlp GENERIC/* /zroot/boot/kernel/
  1. Make /var/empty readonly
Fixit# zfs set readonly=on zroot/var/empty
  1. chroot into /zroot
Fixit# chroot /zroot
  1. Create /etc/rc.conf
Fixit# echo 'zfs_enable="YES"' > /etc/rc.conf
Fixit# echo 'hostname="beastie.mydomain.local"' >> /etc/rc.conf
Fixit# echo 'ifconfig_re0="DHCP"' >> /etc/rc.conf
Note:

Replace re0 with the name of the Network interface for the new system

  1. Create /boot/loader.conf
Fixit# echo 'zfs_load="YES"' > /boot/loader.conf
Fixit# echo 'vfs.root.mountfrom="zfs:zroot"' >> /boot/loader.conf
  1. Change root's password
Fixit# passwd
  1. Set the local time zone
Fixit# tzsetup
  1. Create /etc/mail/aliases.db
Fixit# cd /etc/mail
Fixit# make aliases
  1. Exit from the /zroot
Fixit# umount /dev
Fixit# exit
  1. Install zpool.cache to the ZFS filesystem
Fixit# cp /boot/zfs/zpool.cache /zroot/boot/zfs/zpool.cache

Finish install

  1. Move /zroot/boot into /zroot/bootdir
Fixit# cd /zroot
Fixit# mv boot bootdir/
Fixit# ln -s bootdir/boot /zroot/boot
Fixit# chflags -h sunlink /zroot/boot
  1. Create /etc/fstab
Fixit# mkdir /zroot/etc
Fixit# cat << EOF > /zroot/etc/fstab
# Device			Mountpoint		FStype	Options		Dump	Pass#
/dev/ad0s3a			/bootdir		ufs	rw		0	0
/dev/ad0s3b			none			swap	sw		0	0
EOF
  1. export LD_LIBRARY_PATH 
Fixit# export LD_LIBRARY_PATH=/mnt2/lib
  1. Unmount all zfs filesystems
Fixit# umount /zroot/bootdir
Fixit# zfs unmount -a
  1. Change mount points for zroot pool 
Fixit# zfs set mountpoint=legacy zroot
Fixit# zfs set mountpoint=/tmp zroot/tmp
Fixit# zfs set mountpoint=/usr zroot/usr
Fixit# zfs set mountpoint=/var zroot/var
  1. Exit Fixit mode, and then sysinstall. Remove the FreeBSD install DVD/Memstick and the system will boot using the ZFS root.