FreeBSD on a bootable ZFS mirror • 28 Dec 2011
This is a decription of how I install FreeBSD on a server machine with two or more harddisks, using ZFS, and without swap. I distilled this method from a variety of sources on the Web. It's nothing new or unique; I just document it for myself here.
Power on the server and boot from an USB stick. For this example, I used a FreeBSD-9.0-REL-amd64 USB stick. When the installer comes up, select 'Shell' to drop into a shell.
I like to start with clean disks. If you're unsure, wipe them first (it won't hurt):
dd if=/dev/zero of=/dev/ada0 bs=1m count=1
dd if=/dev/zero of=/dev/ada1 bs=1m count=1
Then, partition the disks:
gpart create -s gpt ada0
gpart create -s gpt ada1
gpart add -b 34 -s 94 -t freebsd-boot ada0
gpart add -b 34 -s 94 -t freebsd-boot ada1
gpart add -t freebsd-zfs ada0
gpart add -t freebsd-zfs ada1
gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada0
gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 1 ada1
# You could even initialize more disks, like ada2, ada3 etc...
Create a zpool with the mirror, and set some options:
zpool create -f -o altroot=/mnt -o cachefile=/var/tmp/zpool.cache \
zroot mirror ada0p2 ada1p2
# For hot spares, you could append to the above command: spare ada2p2 ada3p2
zpool set bootfs=zroot zroot
zfs set checksum=fletcher4 zroot
zfs set atime=off zroot
Install FreeBSD:
chmod 0177 /mnt
cd /mnt ; ln -s usr/home home
sh
cd /usr/freebsd-dist
for file in base.txz lib32.txz kernel.txz doc.txz;
do (cat $file | tar --unlink -xpJf - -C /mnt); done
Note: if you install a 32-bit architecture, you don't need lib32.txz. Include src.txz if you want the kernel source code. You also might want to include ports.txz to install the ports tree, however, I prefer 'portsnap fetch && portsnap extract' after installation, to get really up-to-date ports.
Finishing up:
cp /var/tmp/zpool.cache /mnt/boot/zfs/zpool.cache
echo 'zfs_enable="yes"' >>/mnt/etc/rc.conf
echo 'zfs_load="yes"' >>/mnt/boot/loader.conf
echo 'vfs.root.mountfrom="zfs:zroot"' >>/mnt/boot/loader.conf
touch /mnt/etc/fstab
Now you can reboot. Don't forget to add a root password with 'passwd'.
Comments
Michiel • 6 Sep 2014
The FreeBSD installer nowadays offers this out of the box. No need for above procedure anymore!
andy • 26 Oct 2012
works perfectly, thanks a lot !!!