[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
Current known problem: The original unix is 64bit but diskless machine is 32bit?
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!
#contents
* Set a small subnet for testing PXE [#f0142583]
**What we need [#pe839496]
- 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 [#r1faf503]
***Network setting [#j7b294ed]
- 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
- PXE server has a local IP address
-- IP Address: 172.17.7.57
-- Subnet Mask: 255.255.252.0
- On the client computer, set the IP Address by statically to be:
-- IP Address: 192.168.1.2
-- Subnet Mask: 255.255.255.0
- We adopt the Fedra machine which will be used as the original of diskless
-- IP Address: 172.17.4.178
-- Subnet Mask: 255.255.252.0
***SSH check [#tad4148a]
- 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 [#e9d2e315]
- 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 [#s4cd2a84]
** Install DHCP and TFTP Server etc [#s9d399d8]
- 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 [#nfd5db55]
- 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.
- tftpd is running under the xinetd. We restart xinetd
# service xinetd restart
** Copy system data for booting [#v32daf81]
- We will make file systems under tftpboot f9.
- root includes the system files which is read-only files
- snapshot includes the other files which is read-write files.
# mkdir /tftpboot/f9
# mkdir /tftpboot/f9/root
# mkdir /tftpboot/f9/snapshot
- rsync will be used for copying the files.
# rsync -v -a -e ssh \
--exclude='/proc/*' --exclude='/sys/*' --exclude='/dev/*'\
--exclude='/media/*' --exclude='/tmp/*' --exclude='/misc/*'\
172.17.4.178:/ /tftpboot/f9/root
- 10GB files (10min) are needed. The file system will be used as nfs file.
- When the original machine (172.17.4.178) is updated. We should do rsync again.
- 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 .
** DHCP Configuration [#b4fdd07c]
- Edit /etc/dhcpd.conf. The following is a configuration for a network that uses:
-- 192.168.1.0/255.255.255.0 addressing
-- Dynamic address will be provided between 192.168.1.100 and 192.168.1.240
-- DHCP server (next server) at IP address 192.168.1.10
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 192.168.1.10;
}
class "pxeclients" {
match if substring(option vendor-class-identifier, 0, 9) = "PXEClient";
next-server 192.168.1.10;
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@192.168.1.10
---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 [#r08426e2]
- NFS hosts is PXE server (192.168.1.10).
- Edit /etc/exports
[root@rsaito-necPC rsaito]# cat /etc/exports
/tftpboot/f9/root 192.168.1.0/255.255.255.0(ro,sync,no_root_squash)
/tftpboot/f9/snapshot 192.168.1.0/255.255.255.0(rw,sync,no_root_squash)
-- file system is opened for 192.168.1.0 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 [#nd1b2b49]
- 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
/home/
- files directory is made automatically by system-config-netboot
- GNOME System - Administration - Server Setting - Network Booting Service
-- push Diskless button for the first time
-- then Diskless identifier windows starts
Name f9-diskless
Explanation Fedora core 9
-- NFS information
server 192.168.1.10
directory /tftpboot/f9/root
-- Select the kernel in the 2nd row as a newer Kernel
-- New windows appear
IP address/subnet 255.255.255.0 <- we use subnet
operating system f9-diskless
snapshot name 255 X generate
-- then 255 directory is made.
-- Probably the snapshot name should be IP dependent
[root@rsaito-necPC 255]# pwd
/tftpboot/f9/snapshot/255
[root@rsaito-necPC 255]# ls
boot etc home lib root var
-- Make a symbolic link for booting file
--- FFFFFF00 (255.255.255.0) 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)
--- 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.
-- edit FFFFFF00
default f9-diskless
label f9-diskless
kernel f9-diskless/vmlinuz
append initrd=f9-diskless/initrd.img root=/dev/ram0 init=disklessrc
NFSROOT=192.168.1.10:/tftpboot/f9 ramdisk_size=20318 ETHERNET=eth0
SNAPSHOT=255 ramdisk_blocksize=1024
--- add ramdisk_blocksize=1024 otherwise Kernel Panic occurs.
--- in the present case, Kernel Panic occurs even if ramdisk_blocksize=1024
** Edit initrd.img for NFS mount [#y864dbff]
-- We just follow the instruction at
http://www.atmarkit.co.jp/flinux/rensai/linuxtips/a021pxediskless.html
--- However mount command does not work correctly
http://www.devdrv.co.jp/linux/cpio-initrd-format.htm
# 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?
* Set PXE client [#j2d1c71b]
- 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.
-----
* Current problem of Kernel Panic [#ica8fb5c]
-- /init is not found.
-- /disklessrc is not found.
-- Kernel Panic etc.
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. [#j85b4ea0]
-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
-- 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
![[PukiWiki]](image/c60.png "[PukiWiki]")
