Network Booting Ubuntu using iPXE and NFS

                                

Network Booting

Using iPXE & NFS

Network Booting is a cool technique to boot the operating system in your machine from the network rather than the local hard drive. For example, in the above picture on the right is a desktop machine that does not have any hard drive, on the left we have a laptop. From the laptop, we will serve an OS over the network and the desktop machine will boot & run the OS completely over the network. The router will create the local network and act as a DHCP server. We will use iPXE & NFS mechanisms to do this. if you are interested to learn about the process in depth you can follow this link https://networkboot.org/fundamentals/ 

We will boot the Ubuntu 16.04.3 desktop version so firstly download the OS from http://releases.ubuntu.com/ and extract it. I am sharing my hands-on experience so my paths won't exactly match yours. My Host machine, which is the laptop in this case, is also running Ubuntu 16.04.3 desktop edition. 

First, install the dependencies 

~/diskless-node-pxe-setup$ sudo apt-get install liblzma-dev

Git clone the iPXE project’s source 

~/diskless-node-pxe-setup$ git clone git://git.ipxe.org/ipxe.git

~/diskless-node-pxe-setup$cd ipxe/src

Build the ROM for USB [for initial build test, later we will make the actual ROM] 

~/diskless-node-pxe-setup/ipxe/src$ make bin/ipxe.usb

We will use the NFS service to serve the OS so our host machine needs to have it 

Install NFS kernel Server 

~$sudo apt-get install rpcbind nfs-kernel-server

Open this file using gedit 

~$sudo gedit /etc/exports

Write the path of the extracted OS at the bottom of the file 

/home/hassin/Downloads/ubuntu-16.04.3-desktop-amd64     *(ro,async,no_wdelay,insecure_locks,no_root_squash,insecure,no_subtree_check)

Add NFS support to the PXE ROM 

~/diskless-node-pxe-setup/ipxe/src$ echo "#define DOWNLOAD_PROTO_NFS" >> config/local/general.h

Add script support to the ROM 

Open this file “ipxe/src/config/local/general.h

The IMAGE_SCRIPT macro should be defined [ not commented out] 

Take note of your host machine IP,

~$ ifconfig

for my machine, it was 192.168.0.100 

Create a script 

~/diskless-node-pxe-setup/ipxe-scripts$ cat > ubuntu16-live.ipxe

Open the script 

~/diskless-node-pxe-setup/ipxe-scripts$ gedit ubuntu16-live.ipxe

Add the following lines 

echo Hi, trying to boot ubuntu16-live set server_ip 192.168.0.100 set nfs_path /home/ayx/Downloads/ubuntu-16.04.3-desktop-amd64 kernel nfs://${server_ip}${nfs_path}/casper/vmlinuz.efi || read void initrd nfs://${server_ip}${nfs_path}/casper/initrd.lz || read void imgargs vmlinuz.efi initrd=initrd.lz root=/dev/nfs boot=casper netboot=nfs nfsroot=${server_ip}:${nfs_path} ip=dhcp splash quiet -- || read void boot || read void echo Booting

Save it 

Now make the ROM by embedding the script 

~/diskless-node-pxe-setup/ipxe/src$ make bin/ipxe.usb EMBED=../../ipxe-scripts/ubuntu16-live.ipxe

Insert a pen drive, take note of its drive letter using the “Disks” utility app of ubuntu 

For my case, it was sdb 

~/diskless-node-pxe-setup/ipxe/src$ sudo dd if=bin/ipxe.usb of=/dev/sdb

Export the NFS shares of your host machine 

~$sudo exportfs -ra

Restart NFS-kernel-server 

~$sudo /etc/init.d/nfs-kernel-server restart

Remove the pen-drive , insert it into the desktop machine 

Make sure USB from the boot is enabled, 

Now everything okay then you will be able to use ubuntu over the network