2009.5.21 updated by R. Saito

Current status: finished now we can use the machine as Unix machine

Current problem: it seems that /nfsboot/root should be made for each PXE client.



Current known problem:

  • Use ram disk for each PXE client and the server.
  • Set common place in nfsboot and client specific place.
  • Set update /nfsboot/root update only from one client

A new page for Linux cluster (newtube) is now open.


http://www15.big.or.jp/~yamamori/sun/pxe/nic.html http://docs.fedoraproject.org/install-guide/f10/

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

  • 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.


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 eth0, we set it to have:
    • IP Address:
    • Subnet Mask:
  • PXE server has a local IP address eth1
    • IP Address:
    • Subnet Mask:
    • gateway
    • nameserver
  • On the client computer, set the IP Address by statically to be:
    • IP Address:
    • Subnet Mask:
    • gateway (specified by dhcpd.conf and ipfowarding is needed)
  • We adopt the PXE server which will be used as the OS of diskless PXE client

SSH check

  • Open SSH software on client computer, for example, Putty or any command line software:
    ssh username@
  • If username is "nugraha" and hostname of server is "rsaito-necPC", we must get the following line after succesfully login:
    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 10 machine (PXE server itself) for copying the system.
  • We need to install busy-anaconda in the PXE server machine before copying the system yum install busybox-anaconda

Setting for the PXE server machine

SElinux shoule be permissive mode.

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
    • if you can see name + version, then ok. if not, yum install again.

TFTP Configuration

  • Edit /etc/xinetd.d/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.
  • tftpd is running under the xinetd. We restart xinetd
# service xinetd restart

Copy system data for booting

  • We will make file systems /nfsboot
# mkdir /nfsboot
  • rsync will be used for copying the files.
# rsync -v -a 
--exclude='/proc/*' --exclude='/sys/*' --exclude='/dev/*'\
--exclude='/media/*'   --exclude='/tmp/*' --exclude='/misc/*'\
/ nfsboot
  • 10GB files (10min) are needed. The file system will be used as nfs file.
  • When the original machine ( is updated. We should do rsync again.
  • if we get the file system by network, following command can be used.
# rsync -v -a -e ssh \
--exclude='/proc/*' --exclude='/sys/*' --exclude='/dev/*'\
--exclude='/media/*'   --exclude='/tmp/*' --exclude='/misc/*'\ /nfsboot

DHCP Configuration

  • Edit /etc/dhcpd.conf. The following is a configuration for a network that uses:
    • addressing
    • Dynamic address will be provided between and
    • DHCP server (next server) at IP address
      allow booting;
      allow bootp;
      use-host-decl-names     on;
      ddns-update-style interim;
      ignore client-updates;
      subnet netmask {
      	  option subnet-mask;
      	  option broadcast-address;
      	  range dynamic-bootp;
      host dell {                           # hostname
                     hardware ethernet 00:21:70:c9:eb:60; # MAC address of NIC
                     fixed-address; # corresponding IP address
                     filename "/linux-install/pxelinux.0";
      class "pxeclients" {
             match if substring(option vendor-class-identifier, 0, 9) = "PXEClient";
             filename "/linux-install/pxelinux.0";


  • Turn on dhcpd
# /sbin/service dhcpd restart
# 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
    • Set the TCP/IP to dynamically set for IP address.
    • Connect by ssh
       % putty username@
    • If we can connect, it means DHCP has successfully been configured.
       % ipconfig -a
    • Please keep Mac Address of the client PC
       In this case 00-21-70-c9-eb-60 (Dell PC). 
    • Mac address will be used in pxelinux.cfg directory.
    • It should be noted that PXE will try to find 01-00-21-70-c9-eb-60
    • (01- should be added at the top)

NFS configuration

  • NFS hosts is PXE server (
  • Edit /etc/exports
  • Change firewall for nfs
    • uncomment MOUNTD_PORT
# Port rpc.mountd should listen on.
  • #MOUNTD_PORT=892
  1. MOUNTD_PORT=892
  • Run system-config-firewall
    • add 111 tcp
    • add 111 udp
    • add 892 tcp
    • add 892 udp
      • for 892 port, we set by hand.


  • Edit /etc/sysconfig/nfs
  • check mount from
    # mkdir /mnt/test
    # mount -v -t nfs /mnt/test 
    # cd /mnt/test
    # ls
  • If it does not work, please check the firewall again.
[root@rsaito-necPC rsaito]# cat /etc/exports
  • change filewall
  • file system is opened for network.
  • do not make a space before (ro etc.
  • Start nfs
    # service nfs restart
    [root@rsaito-necPC etc]# cd /etc/rc5.d/
    [root@rsaito-necPC rc5.d]# ./S60nfs restart
    Shutting down NFS mountd:                                  [  OK  ]
    Shutting down NFS daemon:                                  [  OK  ]
    Shutting down NFS quotas:                                  [  OK  ]
    Shutting down NFS services:                                [  OK  ]
    Starting NFS services:                                     [  OK  ]
    Starting NFS quotas:                                       [  OK  ]
    Starting NFS daemon:                                       [  OK  ]
    Starting NFS mountd:                                       [  OK  ]
    [root@rsaito-necPC rc5.d]# ./S60nfs status
    rpc.mountd (pid 12153) is running...
    nfsd (pid 12150 12149 12148 12147 12146 12145 12144 12143) is running...
    rpc.rquotad (pid 12138) is running...

PXE server configuration

  • files directory is made automatically by
  • GNOME System - Administration - Server Setting - Network Booting Service
    • push Diskless button for the first time
    • then Diskless identifier windows starts
Name fedora_10_32bit
Explanation fedora_10_32bit
  • NFS information
directory /nfsboot
  • Select the kernel in the 2nd row as a newer Kernel
  • Automatically it generate /tftpboot/linux-install/fedora_10_32bit/ and
    • /tftpboot/linux-install/fedora_10_32bit/initrd.img
    • /tftpboot/linux-install/fedora_10_32bit/vmliuz
  • New windows appear
IP address/subnet  <- we use subnet information
operating system fedora_10_32bit
Other part should be as it is.
  • /nfsboot/snapshot/ will be generated automatically
  • /nfsboot/snapshot/ is generated, too after specifying the
      IP address
  • FFFFFF00 ( file is generated as above.
# cd /tftpboot/linux-install/pxelinux.cfg
# mv default default.org
# ln -s FFFFFF00 01-00-21-70-c9-eb-60
  • when default exists, PXE client first try to read this.
  • 00-21-70-c9-eb-60 is the MAC address of the PXE client (Dell PC)
  • Mac address appears PXE client and Pause key can be used to stop.
  • PXE try to read 01-00-21-70-c9-eb-60 the file first.
  • An important thing is to put "01-" at the top of the name.
    • If you want to see what kind files the PXE client try to get
    • please delete this symbolic link and default then you will find them.
[root@rsaito-necPC pxelinux.cfg]# cat 01-00-21-70-c9-eb-60

label fedora_10_32bit
   kernel fedora_10_32bit/vmlinuz
   append  initrd=fedora_10_32bit/initrd.img root=/dev/ram0 init=disklessrc
 NFSROOT= ramdisk_size=24753 ETHERNET=eth0  

Set /nfsboot/root/etc

  • /nfsboot/root will be used the root of PXE client.
    • When /nfsboot/root is changed, PXE client UNIX / will be changed.
  • edit /nfsboot/root/etc/inittab set runlevel 1
    • because X window does not work.
    • later we will change back to 5.
  • edit /nfsboot/root/etc/sysconfig/network
[root@rsaito-necPC sysconfig]# cat network
  • edit /nfsboot/root/etc/sysconfig/network-script/ifcfg-eth0
  • rm ifcfg-eth1 should be removed since we have only one NIC.
  • NIC = network interface card.
[root@rsaito-necPC network-scripts]# cat ifcfg-eth0
# Broadcom Corporation NetXtreme BCM5705_2 Gigabit Ethernet
HWADDR=00:21:70:c9:eb:60  <---- set PXE client Mac address
BOOTPROTO=none            <---- change dhcp to none
NETMASK=     <---- set subnet mask
IPADDR=       <---- set fixed IP address
GATEWAY=      <---- now PXE server is gateway

Set PXE client

  • Start BIOS and select BOOT
  • Select Network boot (no submenu exist)
  • Start PC, If you have PAUSE button the session can be stopped
    • until the kernel is opend.

Problems and Solutions

P: init is not found. /disklessrc is not found.

S: use system-config-netboot

S: init should be in /tftpboot/linux-install/32bit_fedora_10/initrd.omg

S: the name of "32bit_fedora_10" is specified by system-config-netboot.

P: I can find initrd.img but not init itself.

S: If you can expand initrd.img as above, you will find init.

S: disklessrc is not generated by system-config-netboot

P: nfs is not mountd

S: setting fire wall is important as above.

  • check NFS4 is selected as trusted services.
  • /etc/rc5.d/S60nfs restart

S: you can check the mount the /nfsboot from the other Linux machine.

  • from flex. mount -t nfs /mnt/nfsboot
  • If you can find root and snapshot directory, it is correct. [#i3d009ae]

P: dhcpd does not work

S: dhcpd is not running. /etc/rc5.d/S65dpcpd restart.

S: after dhcpd restarts, /etc/rc5.d/S56xined restart.

S: check dhcp function by Windows machine.

P: /etc/resolve.conf is not correct.

S: resolve.conf is generated the host computor which is copied by rsync.

P: some file can not be downloaded by Selinux

S: stop SeLinux? for a moment and check it again.

S: we should change the file type. checked by ls -Z.

P: How to know the contents initrd.img which is generated by system-config-netboot?

S: The solution is given by using cpio command

  • extract initrd.img
    # cd /boot
    # mkdir initrd-2.4.9
    # cd initrd-2.4.9
    # zcat ../initrd-2.4.9.img | cpio -i -c
  • compress initrd.img
    # cd /boot/initrd-2.4.9
    # find . | cpio --quiet -c -o | gzip -c > ../initrd-2.4.9-new.img

P: X window is not running and the OS can not be used.

S: edit /nfsboot/root/etc/inittab then change ranlevel to 1,

P: X window should be adjusted to new computor

S: The following seems to work.

  1. Run X -configure which makes /root/xorg.conf.new
  2. cp /root/xorg.conf.new /etc/X11/xorg.conf
  3. xorgcfg  -texmode
  4. startx
  5  if it does not work, edit /etc/X11/xorg.conf (Change driver from ati to vesa?
  6. startx again 

S: If it does not work, try to do the following, too.

# Xorg -configure

Then /root/xorg.conf.new generates. Check this files works well

# X -config /root/xorg.conf.new

If X starts nicely, press [Ctrl]+[Alt]+[F1] to go back to console.

# mv /etc/X11/xorg.conf /etc/X11/xorg.conf.old
# mv /root/xorg.conf.new /etc/X11/xorg.conf

That is all. Reboot this.


P: from PXE client, we can not go to network

S: in PXE server ( Edit /etc/sysctl.conf

S: IP forwarding is necessary.

net.ipv4.ip_forward = 1
for runntine
# echo 1 > /proc/sys/net/ipv4/ip_forward
for setting
# sysctl -p
net.ipv4.ip_forward = 1
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
kernel.sysrq = 0
kernel.core_uses_pid = 1
Then System-> Administration -> Fireall Then select Masquerading 
Check -- All eth+ devices -- then apply.
# service network restart

P: SuperMicro??, X7DCA-L motherboad does not have PXE boot function?

S: Edit BIOS Advanced -> PCI configuration then NIC boot can be enabled.

S: Then set BOOT order by pushing "x" or "+" or "-".

P: What kind NIC does support PXE or IAS


Links for references





Directrories and files

PXE server


  • /tftpboot/linux-install/ system-config-network uses this directory
    • /tftpboot/linux-install/fedora_10_32bit initrd.img and vmlinuz is stored
    • /tftpboot/linux-install/pxelinux.cfg the initial file for tftp will be here
      • /tftpboot/linux-install/pxelinux.cfg/default this should be renamed
      • /tftpboot/linux-install/pxelinux.cfg/FFFFFF00 subnet is specified
      • /tftpboot/linux-install/pxelinux.o
      • /tftpboot/linux-install/msgs


  • /nfsboot/root
  • /nfsboot/snapshot

PXE client

When we try to find "disklessrc fedora", we found the following Web site.

http://d.hatena.ne.jp/adsaria/20080131/1201792574 http://wikiwiki.jp/disklessfun/?FrontPage

The following is the statements which are evetually not used.

  • 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
  • Turn on the tftp service:
    # /sbin/chkconfig tftp on
  • 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 netmask {
    # range;? in the case of dynamic IP address
    option domain-name "dc2.kek.jp";
    option broadcast-address;
    option routers;
    #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;  static IP address for n011
    option dhcp-class-identifier "PXEClient";  needed for PXE
    option next-server;  specify for PXE server
                  is provided by PXE Proxy DHCP server
    # vendor-encapusulated option "next-server" can specify PXE server

Edit initrd.img for NFS mount

  • We just follow the instruction at


  • However mount command does not work correctly



# cp /tftpboot/linux-install/f9-diskless/initrd.img /tmp
# cd /tmp
# mkdir initrd.test
# cd initrd.test
# cp ../initrd.img .
# mkdir initrd
# cd initrd
# zcat ../initrd.img | cpio -i -c
# cd /sbin
# cp /sbin/mount.nfs .
# cp /sbin/umount.nfs .
# cp /sbin/mount.nfs4 .
# cp /sbin/umount.nfs4 .
# cd ..
# find . | cpio --quiet -c -o | gzip -c > ../initrd-new.img
# cd /tftpboot/linux-install/F9-diskless/
# mv initrd.img initrd.img.org
# cp /tmp/initrd-test/initrd-new.img ./initrd.img
  • /tftpboot/linux-install/f9-diskless/initrd.img is generated by
    • system-config-netboot
  • initrd.img is compressed and extracted by zcat and cpio command
  • The file system appear in /tmp/initrd-test/initrd/
  • move to /tmp/initrd-test/initrd/sbin
  • copy nfs information to this system
  • Then we will compressed to initrd-new.img
  • keep the original initrd.img to initrd.img.org
  • copy from initrd-new.img to initrd.img
  • Then this initrd.img should contain nfs information.
  • Question: I do not know what is mount.nfs etc. It seems to be binary.
  • Question: PXE server is 32 bit. The diskless Linux 64 bit OS.
  • Question: It is ok for us to use 32 bit mount.nfs information for 64 bit OS?

PXE server configuration (old)

  • make files.custom in /tftpboot/f9/snapshot
  • in which we put /home/ for making /home directory
[root@rsaito-necPC rc5.d]# cd /tftpboot/f9/snapshot/
[root@rsaito-necPC snapshot]# ls -l
total 12
drwxrwxr-x 8 root root 4096 2009-05-09 08:57 255
-rw-r--r-- 1 root root 1070 2008-08-26 19:09 files
-rw-r--r-- 1 root root    7 2009-05-09 08:52 files.custom
[root@rsaito-necPC snapshot]# cat files.custom

If Selinux complains something, chcon command can be used.

  • chcon command is needed for avoiding selinux security.
# cd /tftpboot
# chcon -R -t type .
  • the original type is XXX which selinux will be refused.
  • We are not sure but we use type =
  • We can check the file type by
# ls -Z .

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Last-modified: 2009-05-23 (Sat) 14:09:02 (2866d)