Installing FreeBSD Root on ZFS using GPT

Contents

Manually Installing FreeBSD on ZFS
Create Partitions
Create the Pool
Create the ZFS file system hierarchy
Configure Boot Environment
Finish install

1. 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.

Boot FreeBSD install DVD or USB Memstick
Select Install, and answer questions such as keyboard layout and hostname
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.
4. 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
```
  2. for Legacy Boot:
```
 gpart add -a 4k -s 512K -t freebsd-boot ada0
 gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada0
```

2. Create Partitions

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

-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.

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.

3. Create the Pool

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)
Mount a tmpfs to /mnt
```
 mount -t tmpfs tmpfs /mnt
```
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, ...

4. 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

5. Configure Boot Environment

 zpool set bootfs=zroot/ROOT/default zroot

6. Finish install

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

Exit Shell Partitioning mode, bsdinstall will continue and complete the installation.
```
 exit
```
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
```

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