Remote Installation of the FreeBSD Operating System without a Remote Console

2.1 Requirements

To continue successfully, you must:

• Have a network accessible operating system with SSH access

• Understand the FreeBSD installation process

• Be familiar with the sysinstall(8) utility

• Have the FreeBSD installation ISO image or CD handy

3.1 Configuration of mfsBSD

Before booting mfsBSD, a few important configuration options have to be set. The most important that we have to get right is, naturally, the network setup. The most suitable method to configure networking options depends on whether we know beforehand the type of the network interface we will use, and the network interface driver to be loaded for our hardware. We will see how mfsBSD can be configured in either case.

Another important thing to set is the root password. This can be done by editing the conf/rootpw.conf file. Please keep in mind that the file will contain your password in the plain text, thus we do not recommend to use real password here. Nevertheless, this is just a temporary one-time password which can be later changed in a live system.

initconf_interfaces="ext1"
initconf_mac_ext1="00:00:00:00:00:00"
initconf_ip_ext1="192.168.0.2"
initconf_netmask_ext1="255.255.255.0"

defaultrouter="192.168.0.1"

defaultrouter="192.168.0.1"
ifconfig_re0="inet 192.168.0.2 netmask 255.255.255.0"

3.2 Building an mfsBSD image

The process of building an mfsBSD image is pretty straightforward.

The first step is to mount the FreeBSD installation CD, or the installation ISO image to /cdrom. For the sake of example, in this article we will assume that you have downloaded the FreeBSD 7.0-RELEASE ISO. Mounting this ISO image to the /cdrom directory is easy with the mdconfig(8) utility:

# mdconfig -a -t vnode -u 10 -f 7.0-RELEASE-amd64-disc1.iso
# mount_cd9660 /dev/md10 /cdrom

Next, build the bootable mfsBSD image:

# make BASE=/cdrom/7.0-RELEASE

3.3 Booting mfsBSD

Now that the mfsBSD image is ready, it must be uploaded to the remote system running a live rescue system or pre-installed Linux distribution. The most suitable tool for this task is scp:

# scp disk.img [email protected]:.

To boot mfsBSD image properly, it must be placed on the first (bootable) device of the given machine. This may be accomplished using this example providing that sda is the first bootable disk device:

# dd if=/root/disk.img of=/dev/sda bs=1m

If all went well, the image should now be in the MBR of the first device and the machine can be rebooted. Watch for the machine to boot up properly with the ping(8) tool. Once it has came back on-line, it should be possible to access it over ssh(1) as user root with the configured password.

4.1 Preparation of Hard Drives

The first task is to allocate disk space for FreeBSD, i.e.: to create slices and partitions. Obviously, the currently running system is fully loaded in system memory and therefore there will be no problems with manipulating hard drives. To complete this task, it is possible to use either sysinstall or fdisk(8) in conjunction to bsdlabel(8).

At the start, mark all system disks as empty. Repeat the following command for each hard drive:

# dd if=/dev/zero of=/dev/ad0 count=2

Next, create slices and label them with your preferred tool. While it is considered easier to use sysinstall, a powerful and also probably less buggy method will be to use standard text-based UNIX® tools, such as fdisk(8) and bsdlabel(8), which will also be covered in this section. The former option is well documented in the Installing FreeBSD chapter of the FreeBSD Handbook. As it was mentioned in the introduction, this article will present how to set up a system with RAID-1 and ZFS capabilities. Our set up will consist of a small gmirror(8) mirrored / (root), /usr and /var file systems, and the rest of the disk space will be allocated for a zpool(8) mirrored ZFS file system. Please note, that the ZFS file system will be configured after the FreeBSD operating system is successfully installed and booted.

The following example will describe how to create slices and labels, initialize gmirror(8) on each partition and how to create a UFS2 file system in each mirrored partition:

# fdisk -BI /dev/ad0 
# fdisk -BI /dev/ad1
# bsdlabel -wB /dev/ad0s1 
# bsdlabel -wB /dev/ad1s1
# bsdlabel -e /dev/ad0s1 
# bsdlabel /dev/ad0s1 > /tmp/bsdlabel.txt && bsdlabel -R /dev/ad1s1 /tmp/bsdlabel.txt 
# gmirror label root /dev/ad[01]s1a 
# gmirror label var /dev/ad[01]s1d
# gmirror label usr /dev/ad[01]s1e
# gmirror label -F swap /dev/ad[01]s1b 
# newfs /dev/mirror/root 
# newfs /dev/mirror/var
# newfs /dev/mirror/usr

4.2 System Installation

This is the most important part. This section will describe how to actually install the minimal distribution of FreeBSD on the hard drives that we have prepared in the previous section. To accomplish this goal, all file systems need to be mounted so sysinstall may write the contents of FreeBSD to the hard drives:

# mount /dev/mirror/root /mnt
# mkdir /mnt/var /mnt/usr
# mount /dev/mirror/var /mnt/var
# mount /dev/mirror/usr /mnt/usr

When you are done, start sysinstall(8). Select the Custom installation from the main menu. Select Options and press Enter. With the help of arrow keys, move the cursor on the Install Root item, press Space and change it to /mnt. Press Enter to submit your changes and exit the Options menu by pressing q.

Go to the Distributions menu, move the cursor with the arrow keys on the Minimal option, and check it by pressing Space. This article uses the Minimal distribution in order to save network traffic, because the system itself will be installed over ftp. Exit this menu by choosing Exit option.

In the Media menu, select FTP. Select the nearest mirror and let sysinstall assume that the network is already configured. You will be returned back to the Custom menu.

Finally, perform the system installation by selecting the last option, Commit. Exit sysinstall when it finishes the installation.

4.3 Post Installation Steps

The FreeBSD operating system should be installed now; however, the process is not finished yet. It is necessary to perform some post installation steps in order to allow FreeBSD to boot in the future and to be able to log in to the system.

You must now chroot(8) into the freshly installed system in order to finish the installation. Use the following command:

# chroot /mnt

To complete our goal, perform these steps:

• Copy the GENERIC kernel to the /boot/kernel directory:

  # cp -Rp /boot/GENERIC/* /boot/kernel
  

• Create the /etc/rc.conf, /etc/resolv.conf and /etc/fstab files. Do not forget to properly set the network information and to enable sshd in the /etc/rc.conf file. The contents of the /etc/fstab file will be similar to the following:

  # Device                Mountpoint      FStype  Options         Dump    Pass#
  /dev/mirror/swap        none            swap    sw              0       0
  /dev/mirror/root        /               ufs     rw              1       1
  /dev/mirror/usr         /usr            ufs     rw              2       2
  /dev/mirror/var         /var            ufs     rw              2       2
  /dev/cd0                /cdrom          cd9660  ro,noauto       0       0
  

• Create the /boot/loader.conf file, with the following contents:

  geom_mirror_load="YES"
  zfs_load="YES"
  

• Perform the following command, which will make ZFS available on the next boot:

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

• Add additional users to the system using the adduser(8) tool. Do not forget to add a user to the wheel group so you may obtain root access after the reboot.

• Double-check all your settings.

The system should now be ready for the next boot. Use the reboot(8) command to reboot your system.