History of PXE Server (Open)(No. 8)

[by Nugraha and Saito, 2009.05.09]

Current status: Not finished yet. We suceeded dhcp and tftp initial files.

Current problem: Error Kernel panic: not found /init during starting linux

We want to make a diskless computing system so that we need a PXE Server. PXE stands for "Pre-boot eXecution Environment". PXE is a special extension of services provided by the Dynamic Host Configuration Protocol (DHCP). It uses a Trivial File Transfer Protocol (TFTP) server to provide minimal boot to a network client. Let's try to configure it!

Set a small subnet for testing PXE
- What we need
- Checking
  - Network setting
  - SSH check
Setting for the original Linux machine from which we copy the system
Setting for the PXE server machine

Set a small subnet for testing PXE†

↑

What we need†

A computer with linux operating system to be configured as a server. Here we use Fedora Linux. This computer should have at least two network interface cards (NIC). One of the cards will be used to connect the server with client.
Computer that acts as a client. For a checking purpose we need this computer to have SSH facility (it does not matter to use Windows or Linux).
Network hub and cables.

↑

Checking†

↑

Network setting†

Turn on the hub, connect a network cable from Fedora Linux computer (PXE server) to the hub (e.g. to channel 1).
Connect again a network cable from the client computer (Windows/Linux) to the hub (e.g. to channel 2).
Open Network configuration on Fedora Linux using root privilege. We should set network interface card that has been connected to the hub.
Assuming the network card is eth1, we set it to have:
- IP Address: 192.168.1.10
- Subnet Mask: 255.255.255.0
On the client computer, set the IP Address by statically to be:
- IP Address: 192.168.1.2
- Subnet Mask: 255.255.255.0

↑

SSH check†

Open SSH software on client computer, for example, Putty or any command line software:
```
ssh username@192.168.1.10
```
If username is "nugraha" and hostname of server is "rsaito-necPC", we must get the following line after succesfully login:
```
nugraha@rsaito-necPC:~$
```
it means that we can access the server from the client.

↑

Setting for the original Linux machine from which we copy the system†

We use fedora 8 machine 172.17.4.178 for copying the system.
We need to install busy-anaconda in the 172.17.4.178 machine before copying the system

172.17.4.178:# yum install busybox-anaconda

↑

Setting for the PXE server machine†

↑

Install DHCP and TFTP Server etc†

Install dhcp, syslinux, tftp-server, nfs-utils, system-config-netboot(su root)

# yum install dhcp 
# yum install syslinux 
# yum install tftp-server
# yum install nfs-utils
# yum install system-config-netboot

Check if the software is nicely installed
```
# rpm -qa | grep syslinux
syslinux-2.2.2.2.2
```
- if you can see name + version, then ok. if not, yum install again.

↑

TFTP Configuration†

Edit /etc/xined/tftp of the PXE server machine

# default: off
# description: The tftp server serves files using the trivial file transfer \
#       protocol.  The tftp protocol is often used to boot diskless \
#       workstations, download configuration files to network-aware printers, \
#       and to start the installation process for some operating systems.
service tftp
{
       disable                 = no
       socket_type             = dgram
       protocol                = udp
       wait                    = yes
       user                    = root
       server                  = /usr/sbin/in.tftpd
       server_args             = -s /tftpboot
       per_source              = 11
       cps                     = 100 2
       flags                   = IPv4
}

(1) disable = no, and (2) server_args = -s /tftpboot should be changed.
possible troubles: (1) tftp does not work, (2) tftp does not find the files.

@@@

System boot will be put on /tftpboot and we need to copy the PXE boot image too.
```
su -
cd /tftpboot
cp /usr/lib/syslinux/pxelinux.0 .
```

Create a minimal /tftpboot/pxelinux.cfg file

DEFAULT pxeboot
TIMEOUT 50
LABEL pxeboot
     KERNEL vmlinuz
     APPEND initrd=initrd.img
ONERROR LOCALBOOT 0

Turn on the tftp service:
```
# /sbin/chkconfig tftp on
```

↑

DHCP Configuration†

Edit /etc/dhcpd.conf. The following is a configuration for a network that uses:

192.168.1.0/24 addressing
Dynamic address will be provided between 192.168.1.100 and 192.168.1.240

DHCP/PXE server at IP address 192.168.1.1

allow booting;
allow bootp;
ddns-update-style interim;
ignore client-updates;
subnet 192.168.1.0 netmask 255.255.255.0 {
	  option subnet-mask 255.255.255.0;
	  option broadcast-address 192.168.1.255;
	  range dynamic-bootp 192.168.1.100 192.168.1.240;
	  next-server 192.168.1.1;
}

The following is another sample dhcpd.conf by specifying MAC address

# dhcpd.conf
# common place for all
use-host-decl-names on; host name and the host name in config file are the same
default-lease-time 600;
max-lease-time 7200;
#
# common for a subnet, we can make a group of host by "host", too
subnet 192.168.197.0 netmask 255.255.255.0 {
# range 204.254.239.10 204.254.239.20;? in the case of dynamic IP address
option domain-name "dc2.kek.jp";
option broadcast-address 192.168.197.255;
option routers 192.168.197.1;
}
#
#host entities The following is how to set static IP address(bootp type)
host n011 { since use-host-decl-names is on, we can use the host name
hardware ethernet 00:D0:B7:1B:12:ED;  MAC address
fixed-address 192.168.197.31;  static IP address for n011
option dhcp-class-identifier "PXEClient";  needed for PXE
option next-server 192.168.197.11;  specify for PXE server
              is provided by PXE Proxy DHCP server
}
# vendor-encapusulated option "next-server" can specify PXE server

Turn on dhcp and xinetd

# /sbin/service dhcpd start
# /sbin/service xinetd start
# chkconfig dhcpd on
(the last line is for activating dhcp on booting process)

Check if the dhcp server can work. Open a client computer which is connected to server and set the TCP/IP to dynamically set for IP address. Then try again:
```
 ssh username@192.168.1.1
```
If we can connect, it means DHCP has successfully been configured.

↑

Copy system data for booting†

172.17.4.178:/# yum install busybox-anaconda

# mkdir /tftpboot/f9
# mkdir /tftpboot/f9/root
# mkdir /tftpboot/f9/snapshot
# rsync -v -a -e ssh \
--exclude='/proc/*' --exclude='/sys/*' --exclude='/dev/*'\
--exclude='/media/*'   --exclude='/tmp/*' --exclude='/misc/*'\
172.17.4.178:/ /tftpboot/f9/root

History of PXE Server (Open) (No. 8)