Installing FreeBSD 9.x Root on ZFS using GPT

Contents

Creating a bootable ZFS Filesystem
Installing FreeBSD to the ZFS filesystem
Finish install

1. Creating a bootable ZFS Filesystem

Boot FreeBSD Install USB Memstick
Choose LiveCD when asked
Mount Root filesystem read-writeable to prevent further problems
```
 mount -rw /
```
Create GPT Disk
```
 Fixit# gpart create -s gpt ad0
```
Note:
- If the disk already contains a partitioning scheme, and this scheme would first need to be destroyed using:
```
 Fixit# gpart destroy ad0
```
Create the boot, swap and zfs partitions
```
 Fixit# gpart add -s 64K -t freebsd-boot ad0
 Fixit# gpart add -s 4G -t freebsd-swap -l swap0 ad0
 Fixit# gpart add -t freebsd-zfs -l disk0 ad0
```
This creates 3 partitions. The first partition will contains the gptzfsboot loader which will be able to load /boot/loader or /boot/zfsloader (9.0-CURRENT) from a ZFS partition. The second partition is a 4 GB swap partition. The third partition is dedicated to the ZFS zpool and uses the remaining space on the disk.
Note:
1. While a ZFS Swap Volume can be used instead of the freebsd-swap partition, crash dumps can't be saved to the ZFS Swap Volume.
Install the Protected MBR (pmbr) and gptzfsboot loader
```
 Fixit# gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ad0
```
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
```

Load ZFS kernel module

 Fixit# kldload opensolaris.ko
 Fixit# kldload zfs.ko

Create ZFS Pool zroot
```
 Fixit# zpool create zroot /dev/gpt/disk0
 Fixit# zpool set bootfs=zroot zroot
```
Note:
- zroot is the name of the ZFS Pool, it could be anything (i.e. tank, data, ...)

2. Installing FreeBSD to the ZFS filesystem

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 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=lzjb  -o exec=on      -o setuid=off   zroot/var/tmp
 Fixit# chmod 1777 /zroot/var/tmp

Note:

Compression may be set to on, off, lzjb, gzip, gzip-N (where N is an integer from 1 (fastest) to 9 (best compresion ratio. gzip is equivalent to gzip-6).
Compression will cause some latency when accessing files on the ZFS filesystems. Use compression on ZFS filesystems which will not be accessed that often.

Install FreeBSD to zroot using bsdinstall

When asked about Partitioning choose "shell"

Mount filesystem to /mnt

  zfs set mountpoint=/mnt zroot
  zfs set mountpoint=/mnt/tmp zroot/tmp
  zfs set mountpoint=/mnt/usr zroot/usr
  zfs set mountpoint=/mnt/var zroot/var

  zfs mount -a

Exit shell and go back to bsdinstall to let it install your FreeBSD system
```
  exit
```

Make /var/empty readonly

 Fixit# zfs set readonly=on zroot/var/empty

chroot into /zroot
```
 Fixit# chroot /mnt
```

Create /etc/rc.conf

 Fixit# echo 'zfs_enable="YES"' >> /etc/rc.conf

Create /boot/loader.conf

 Fixit# echo 'zfs_load="YES"' > /boot/loader.conf
 Fixit# echo 'vfs.root.mountfrom="zfs:zroot"' >> /boot/loader.conf

Exit from chroot
```
 Fixit# exit
```

Install zpool.cache to the ZFS filesystem

 Fixit# cp /boot/zfs/zpool.cache /boot/zfs/zpool.cache

3. Finish install

Create /etc/fstab

 Fixit# cat << EOF > /mnt/etc/fstab
 # Device                       Mountpoint              FStype  Options         Dump    Pass#
 /dev/gpt/swap0                 none                    swap    sw              0       0
 EOF

Unmount all zfs filesystems
```
 Fixit# zfs unmount -a
```

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

Exit Fixit mode, and then bsdinstall. Remove the FreeBSD install DVD/Memstick and the system will boot using the ZFS root.

CategoryZfs