Installing FreeBSD with a ZFS root on a PowerMac G5

Suppose you have a nice PowerMac G5 big beast around and want to install a modern operating system on it. Suppose that you want FreeBSD to run on it. Suppose that you would like to use ZFS as much as possible, say to use the machine as a NAS.

If all of the above apply to you, you have come to the right place! Read on for how I got FreeBSD 10.0-CURRENT with a ZFS root to work on a PowerMac G5. I am pretty sure the instructions here apply to other PowerPC-based machines as well, although the specific details on how to set up the boot loader most likely differ.

Note that I performed this procedure from a FreeBSD installation residing on the second drive of the machine. I suppose everything described here can be done in the same manner from the live shell provided by the installer, although the paths and the ordering of the instructions might be slightly different. (Tip: you might want to reserve the first few GB of your drive for a plain FreeBSD installation to use for recovery-purposes only, and you can later use this simplified system to bootstrap the real one as described below.)

The following instructions assume that the disk onto which FreeBSD will be installed is ada0 and that the whole disk is devoted to FreeBSD. In other words: the procedure will wipe all data on ada0; you have been warned.

For reference, the disk layout used in the procedure below looks as in the following table. This is based on a 650G hard disk with 6G of RAM:

Index	Device	Label	Type	Size
1	ada0s2	BOOTSTRAP	apple-boot	800K
2	ada0s3	BOOT	freebsd-ufs	512M
3	ada0s4	SWAP	freebsd-swap	12G
4	ada0s5	ROOT	freebsd-zfs	Remaining

The step-by-step instructions:

Initialize the partition table in ada0:
```
gpart create -s APM ada0
```

Create an Apple_Bootstrap partition, a boot partition, a swap partition, and the ZFS pool:

gpart add -l BOOTSTRAP -s 800K -t apple-boot ada0
gpart add -l BOOT -s 512M -t freebsd-ufs ada0
gpart add -l SWAP -s 12G -t freebsd-swap ada0
gpart add -l ROOT -t freebsd-zfs ada0

Install the stage one bootloader onto the BOOTSTRAP partition:
```
gpart bootcode -p /boot/boot1.hfs -i 1 ada0
```

Load the ZFS modules:

kldload /boot/kernel/opensolaris.ko
kldload /boot/kernel/zfs.ko

Create the ZFS pool:

mkdir /boot/zfs
zpool create zroot /dev/ad0s5
zpool set bootfs=zroot zroot

Create any file systems you desire under the new pool. I am only going to separate /home in this post to prevent a lot of verbosity. However, the original instructions in which I am basing this post contain a more detailed list on what you might want to split out:
```
zfs create setuid=false zroot/home
```

Create and mount the /boot file system:

newfs /dev/ada0s3
mkdir /zroot/boot
mount /dev/ada0s3 /zroot/boot

Unpack the desired sets:

for s in base docs kernel; do
    tar -xzvpf .../${s}.tgz -C /zroot
done

Create a new /zroot/etc/rc.conf with at least the following:

zfs_enable="YES"
hostname="your.name.example.com"
ifconfig_gem0="DHCP"

Create a new /zroot/boot/loader.conf with at least the following:
```
zfs_load="YES"
vfs.root.mountfrom="zfs:zroot"
```

Install the ZFS boot cache:

cp /boot/zfs/zpool.cache /zroot/boot/zfs/zpool.cache

Perform basic system setup:

chroot /zroot
# IN THE CHROOT
passwd
tzsetup
cd /etc/mail
make aliases
exit

Create a new /zroot/etc/fstab with at least the following (although the tmp is optional):

# Device    Mountpoint  FStype  Options Dump    Pass#
/dev/ada0s3 /boot       ufs     rw      1       1
/dev/ada0s4 none        swap    sw      0       0
tmpfs       /tmp        tmpfs   rw      0       0

Fix up the /boot file system. This is horrible but is the best I've gotten so far. The problem is that the boot.hfs loader seems to have /boot/loader hardcoded in it, which obviously breaks when /boot is a separate partition. A symlink of . to boot does not work, unfortunately. So:
```
cd /zroot/boot
mkdir boot
cd boot
ln -s ../* .
rm loader ; ln ../loader loader
```

Unmount file systems and finish the ZFS setup:

umount /zroot/boot
zfs unmount -a
zfs set mountpoint=legacy zroot
zfs set mountpoint=/home zroot/home

Reboot, enter OpenFirmware (Option+Command+O+F) and set up the machine for automatic booting:
```
setenv auto-boot? true
setenv boot-device sd0:2,\:tbxi
reset-all
```

And that should be it! A fully-manual installation of FreeBSD just to get ZFS up and running for the root file system... but I hope you enjoy the results :-)

For further reference, here are the original instructions on which the above steps are based:

Installing FreeBSD with a ZFS root on a PowerMac G5

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