It is important to have a clean separation of concerns, both in your code, as in your machine’s setup. If you are looking for information on how to get a ZFS FreeBSD setup on one hard-drive with multiple partitions, this is what you want.
This guide assumes you want to install FreeBSD and manually create the ZFS 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.
- Boot FreeBSD install DVD or USB Memstick
- Select Install, and answer questions such as keyboard layout and hostname
- When prompted to partition the disk, choose the
shelloption. In this mode you are expected to create a root file system mounted under/mntthat the installer will install the operating system into.
Now to the installation steps, start by determining which disks you wish to use:
camcontrol devlist # or alternatively geom disk list
That should return something like
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 devices name in all
commands below.
Proceed to create a fresh partition table, erasing ALL data on the disk!:
# The first command is not needed if you are working on an empty new disk gpart destroy ada0 gpart create -s gpt ada0
Then create the boot code partition:
for Legacy Boot:
# Confirmed working on FreeBSD 13 gpart add -a 4k -s 512K -t freebsd-boot ada0 gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada0
for UEFI Boot we will need more space and some more manual steps:
# Confirmed working on FreeBSD 13 gpart add -t efi -s 40M ada0 newfs_msdos -F 32 -c 1 /dev/ada0p1 mount -t msdosfs /dev/ada0p1 /mnt mkdir -p /mnt/EFI/BOOT cp /boot/loader.efi /mnt/EFI/BOOT/BOOTX64.efi umount /mnt
We will now be creating the needed partitions to setup the system as we wish. I will be working with a 20GB hard drive, which I want to split in 3 partitions. 2GB for Swap, 10 GB for the FreeBSD installation and the remaining (8GB) for the Jails storage, in a secondary pool which will later be created.
Note that 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.
Some of the gpart options explained: * -a {number}: controls
alignment. * -s {size}: sets the size of the partition, if not set, it
will default to the remaining space on the disk. * -l {name}: sets the
label for the partition
gpart add -a 1m -s 4G -t freebsd-swap -l swap0 ada0 gpart add -a 1m -s 10G -t freebsd-zfs -l disk0 ada0 gpart add -a 1m -t freebsd-zfs -l disk1 ada0
Find the device for the freebsd-zfs partition created above with
gpart show -p ada0
=> 40 41942960 ada0 GPT (20G)
40 1024 1 freebsd-boot (512K)
1064 984 - free - (492K)
2048 4194304 2 freebsd-swap (2.0G)
4196352 20971520 3 freebsd-zfs (10G)
25167872 16773120 4 freebsd-zfs (8.0G)
41940992 2008 - free - (1.0M)
Our FreeBSD installation will be on ada0p3.
For proceeding with the install we will mount a tmpfs filesystem to
/mnt with:
mount -t tmpfs tmpfs /mnt
We will assume zroot as the name of the ystem’s zpool, it could be
anything (i.e. tank, data, mypool), and to create it we do:
zpool create -o altroot=/mnt zroot ada0p3
We will use the lz4 compression algorithm, since it is fast enough to be used by default, even for uncompressible data. It can be enabled with:
zfs set compress=on zroot
We will then create a Boot Environment hierarchy with:
zfs create -o mountpoint=none zroot/ROOT zfs create -o mountpoint=/ -o canmount=noauto zroot/ROOT/default mount -t zfs zroot/ROOT/default /mnt
and then proceed to create the rest of filesystems required for FreeBSD to be installed to this ZFS Pool:
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
then we will set a symlink to home, and set the correct permissions with:
ln -s /usr/home /mnt/home chmod 1777 /mnt/var/tmp chmod 1777 /mnt/tmp
We can then finalize the zpool creation, by setting the boot environment configuration:
zpool set bootfs=zroot/ROOT/default zroot
To finish the installation, we will create a new entry in the fstab of
the installer, which later will be stored in our system. Now is your
opportunity to attach other devices if needed as well, but for this
tutorial, simply adding the swap is enough:
cat << EOF > /tmp/bsdinstall_etc/fstab # Device Mountpoint FStype Options Dump Pass# /dev/gpt/swap0 none swap sw 0 0 EOF
We can then exit the shell Partitioning mode, at which point
bsdinstall will continue and complete the installation.
In the post installation step, when asked if you would like to drop into the installed system, choose yes, and execute the following:
sysrc zfs_enable="YES" echo zfs_load="YES" >> /boot/loader.conf
You are now ready to reboot into your newly installed FreeBSD system.
Simply type exit at the current prompt, and eject the installation
media, when the machine restarts.