PXEboot

I set up my Via EPIA 800 to run Debian using this method. I use it to configure servers at remote locations with just a little bit of help from local people. ("...Now push the reset button. Thanks.")

Using PXEboot with Debian

1. Client requests network information from BOOTP / DHCP server
2. Client requests a file containing boot code via tftp
3. The file instructs the client what to do next; load a file pxelinux.cfg/* where * is either a piece of its MAC address or 'default' (which is what I use)
4. 'default' gives you boot menu stuff; you have to select something or hit Enter
5. The kernel loads and the Debian installer starts up.

On the Debian server

Install these packages

dhcp server: dhcp3-server

tftp server: tftpd-hpa
When the installer asks "Should it be started from inet?", say 'yes'

tftp client: (useful for testing the server) tftp-hpa

You have to dig up a copy of the debian-installer file tree and put it in /var/lib/tftpboot. Then make symlinks from /var/lib/tftpboot/pxelinux.0 and pxelinux.cfg to the real ones lurk in the debian_installer tree.

Configuration

Generally I put a configuration for each machine into /etc/dhcp3/dhcpd.conf so that I have control over what happens when a given machine connects. The critical lines to add to dhcpd.conf are

# PXE-specific configuration directives...
  next-server 192.168.123.130; # that's this server or could be elsewhere...
  filename "/pxelinux.0";

host clientname {
  hardware ethernet mac-address;
  fixed-address ip address of your chosing;
  filename "pxelinux.0";
}

This tells the client what file to grab via tftp. The files for tftp should be installed in /var/lib/tftpboot (see comment above on symlinks)

Many Linux distributions (including Redhat, Debian, Trustix, Ubuntu, and SuSe) have network install support. You just have to poke around to find the files.

Booting the client

Set the client to boot from LAN or Network. Then boot it. If you are near the client and can look at the console,

• you should see the "UNDI" boot stuff. Notably you should see the client get the IP address that you set up for it in dhcpd.conf.
• next you should see it connect to the tftp server. It will show a series lines as it tries to find a pxelinux.cfg file; it will uses its MAC address piece by piece and then give up and load pxelinux.cfg/default
• if the pxelinux.cfg loads then it should fire up the installer and from then on, the screens are what you'd see if you booted from a cdrom.

System Rescue mode

But wait! I want to do a remote bare metal rescue mode! Currently I have to instruct someone to push the "magic cd" into the computer and reboot it. This taxes everyone's patience because later I have to call them and ask them to remove it and stand by to see if the system will reboot correctly. The "magic cd" is a customized version of SystemRescueCD with ssh enabled on it and a root password of my choosing stored in it.

The SystemRescueCD project has died by the way. So it's only a matter of time until we cannot use the magic disk anymore. Look at FrozenTech for alternatives.

Olive looks like fun.

I want PXEboot into the SystemRescue tool kit and I want the result to have a serial console. I use a serial console. This is set up already. I just want to ask someone to push the reset button (or automate that too someday) and have the system come up. In theory I can just ssh in once the system pxeboots; I know it has a functional network card if it pxebooted, right? But I want it anyway. I am not guaranteed that the operating system will be able to find the network card after the kernel loads, now am I?

Then I can control whether it boots from network or not by modifying my dhcp server settings. If I uncomment the 'file' line it netboots, otherwise it boots from its own hard drive. If this works well enough I might quit having anything boot from a hard drive ever again! :-)

So how about a Debian diskless/NFS installation?

http://homex.subnet.at/~max/diskless/index.php

Make the server do NFS. Apply appropriate security measures, I choose to use the nfs-kernel-server package.

I intend to work with the 2.6.8-3 kernel since that's what I get in the current Debian stable release for a 2.6 kernel. I have a VMware machine running with it for development and test purposes.

The initrd image has to have the nfs pieces added to it so it can mount root via nfs.

nfs
lockd
sunrpc
af_packet

Be sure to check nfsboot.txt in /usr/src/linux/Documentation.

See "Rescue is possible" PXEboot version http://www.tux.org/pub/people/kent-robotti/looplinux/rip/

More information

Remote Network Boot via PXE
Installing Debian via PXE