Headless Debian Installation

Wherein we read Aaron's adventure installing Debian on an Apple Xserve, kallisti, without a keyboard or monitor. It won't quite be touchless, though. I'll have to push buttons on the front panel to get it to boot over the network.

The hope is to get it up far in the installer to get it to running the OpenSSH server, and finish the install remotely.

Hardware we'll be touching

kallisti, an Apple Xserve G5 DP, circa 2004-2006. Installation of Debian is happening here.
sacredchao, a Dell PowerEdge 1950. The main server at home.
Power cables, Ethernet cables

Preparing to boot the network installer

DHCP server setup

Get DHCP configured to hand an IP address to the Xserve, default route, DNS settings, and TFTP boot info to the Xserve. Here's the snipped from my dhcpd.conf file:

host kallisti {
        # Apple Xserve G5 s/n QP5260YBSLZ
        hardware ethernet 00:0d:93:9d:7a:8f;
        fixed-address 172.16.0.139;
        option host-name "kallisti";
        # un-comment the next two lines to enable TFTP boot this system
        next-server 172.16.0.1;
        filename "yaboot";      # new-world PowerMac boot loader
        # comment the previous two lines disable TFTP boot of this system
}

Make installer files available by TFTP

Put the following files in the TFTP server's root directory. These can be retrieved from http://http.us.debian.org/debian/dists/wheezy/main/installer-powerpc/current/images/powerpc64/netboot/

vmlinux
initrd.gz
yaboot
yaboot.conf
boot.msg

Fixing up the firmware situation for the installer

At this point, if all goes as planned, netbooting the Xserve will get us up, into the Debian installer, and unable to talk to the network because the tg3 Ethernet adapters need non-free firmware blobs to work. This can be fixed like so:

mv initrd.gz initrd.gz.orig
cd /tmp
mkdir prep-installer-initramfs-with-tg3-firmware
wget http://cdimage.debian.org/cdimage/unofficial/non-free/firmware/stable/current/firmware.tar.gz
gzip -dc firmware.tar.gz | tar xvvf - ./firmware-linux-nonfree_0.36+wheezy.1_all.deb    # this has the tg3 firmware inside
cd prep-installer-initramfs-with-tg3-firmware
gzip -dc /srv/tftp/RackMac3,1/initrd.gz.orig | sudo cpio -iv            # unpack the initramfs archive (run as root so included device files are created)
dpkg-deb -x ../firmware-linux-nonfree_0.36+wheezy.1_all.deb .           # unpack the non-free firmware package
find * -depth -print0 | cpio -o0a -R 0:0 -Hnewc > ../initrd+firmware
gzip -9v ../initrd+firmware                                             # leaves a new initramfs image for the boot loader to pick up
sudo install -o root -g root -m 644 -v -b ../initrd+firmware.gz /srv/tftp/RackMac3,1/initrd.gz     # put it where yaboot can get it

And it might be nice to make sure we haven't inadvertently removed anything from the Debian-supplied initramfs image. Give this a go:

diff -u <(lsinitramfs /srv/tftp/RackMac3,1/initrd.gz~ | tail -n+2 | sort) <(lsinitramfs /srv/tftp/RackMac3,1/initrd.gz | tail -n+2 | sort)

If this returns any lines that begin with a '-', something was left out of the new initramfs image. Investigation is in order.

Important Note: This will let the Debian installer talk to the network with the server's tg3 Ethernet adapters. The installed system will still need to have the non-free firmware packages installed in order to run.

Boot loader config tweaks

Add this stanza to the yaboot.conf downloaded from the Debian FTP mirror:

image=/RackMac3,1/vmlinux
        label=touchless
        initrd=/RackMac3,1/initrd.gz
        initrd-size=28652        # this value was computed by dividing the uncompressed size of the initramfs image (find with "gzip -l") by 1024 and rounding up to the next integer.
        append="priority=low --"
        read-only

And change the value for "default" near the top of the file to "touchless" like so:

default=touchless