2008年6月23日 (一) 21:51的版本

文章出处:

http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch25_:_Network-Based_Linux_Installation

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简介

Fedora Linux可以让你通过网络连接使用kickstart服务器安装操作系统统。这是速度远远超过使用CD并且过程可以自动化。过程是相当简单的：

• 连接新的服务器（客户端）到同一网络的预先加载安装文件服务器（安装服务端）.

• 在客户端用一个专门启动cd开机.
• 输入喜欢的安装方法(FTP,HTTP,NFS)和所需的网络参数.
• 安装程序然后继续到熟悉的Fedora Linux安装界面上.输入您的选择,后完成安装.

本章将简单介绍一下如何进行这项设定,以及三种使用方法.使用安装服务器(bigboy)和IP地址192.168.1.100.

设立安装服务器

kickstart可以配置为FTP，NFS或Apache服务器。下面的解释是每一种方法，但我的经验一直认为，Apache服务器有许多的优点可以超过其他两项。

使用Web服务器作为kickstart是一般较容易，因为：

• 有时，一个kickstart服务器位于远程网络，经常要通过防火墙.严格的防火墙规则比起FTP或NFS，HTTP更容易配置.
• 对于NFS和FTP,以"http://"为名称所存取档案,对用户来说是较为熟悉的.当您配置文件自动进行kickstart安装这是很重要的.
  

基本准备

在这个例子中我们要设立一个kickstart服务器,用于 Fedora Core安装.所有必要的文件将被放置在/data/network-install目录.

创建安装目录

我们将首先创建目录/data/network-install/RPM 和/data/network-install/ISO，复制必要的文件

[root@bigboy tmp]# mkdir -p /data/network-install/RPM
[root@bigboy tmp]# mkdir -p /data/network-install/ISO

你现在需要把网络安装的驱动程序文件复制到相应的目录中.

复制文件

HTTP,NFS和FTP的kickstart方法,都需要安装文件复制到kickstart服务器.这里这样做：

1) 为您的CD ROM驱动器创建一个挂载点.

[root@bigboy tmp]# mkdir /mnt/cdrom

2) 挂载Fedora CD ROM.

[root@bigboy tmp]# mount /dev/cdrom /mnt/cdrom

3) 复制基本文件到硬盘

[root@bigboy tmp]# cp -r /mnt/cdrom/* /data/network-install/RPM

4) 卸载CD ROM和eject命令开启光驱.

[root@bigboy tmp]# umount /dev/cdrom
[root@bigboy tmp]# eject cdrom

5)重复第2-4步复制所有的cd中的文件，覆盖文件时会有提示.

注意: 你也可以选择重网站FTP下载你需要的文件到/data/network-install/RPM目录.

HTTP & FTP Preparation

复制每个安装CD中的内容到/data/network-install/RPM目录.这将需要约3-5 GB的空间.完成后,/data/network-install/RPM目录看起来应该这样:

[root@bigboy tmp]# ls -1 /data/network-install/RPM
eula.txt
Fedora
fedora.css
GPL
images
index.html
isolinux
README-Accessibility
RELEASE-NOTES-en_US.html
repodata
RPM-GPG-KEY
RPM-GPG-KEY-beta
RPM-GPG-KEY-fedora
RPM-GPG-KEY-fedora-extras
RPM-GPG-KEY-fedora-legacy
RPM-GPG-KEY-fedora-rawhide
RPM-GPG-KEY-fedora-test
RPM-GPG-KEY-rawhide
stylesheet-images 
[root@bigboy tmp]#

NFS Preparation

创建安装光盘的ISO影像,复制他们到/data/network-install/ISO目录.这将需要约3-5 GB的空间.您也可以从Fedora的网站下载ISO影像或使用Fedora的光碟，如下所示.如果您创建了CD的iso文件,确保他们的文件名和你从Fedora网站下载的一样.

请按照下列步骤去操作每个CD:

[root@bigboy tmp]# cd /data/network-install/ISO
[root@bigboy ISO]# dd if=/dev/cdrom of=filename.iso bs=32k
...
...
[root@bigboy ISO]# eject cdrom

注意: 你可以用mkisofs 命令建立iso文件.你也安装新版本的mkisofs RPM.这个命令需要一个加载的cdrom,所以不要忘了mount命令.

[root@bigboy ISO]# mount /mnt/cdrom
[root@bigboy ISO]# mkisofs -J -r -T -o filename.iso /mnt/cdrom
[root@bigboy ISO]# eject cdrom

Setup Your Webserver

You will now have to setup Apache to give the file listings of your /data/network-install/RPM and /data/network-install/ISO directories by pointing your browser to the URL http://192.168.1.100/network-install/RPM/ or http://192.168.1.100/network-install/ISO/ respectively. A sample /etc/httpd/conf.d/kickstart.conf configuration is below. Remember to restart Apache to make these settings take effect.

NameVirtualHost 192.168.1.100
 
#
# For HTTP Installations
#
<VirtualHost 192.168.1.100>
  DocumentRoot /data/
</VirtualHost>

<Directory /data/network-install>
   Options +Indexes
   AllowOverride AuthConfig
   order allow,deny
   allow from all
</Directory>

Setup Your FTP Server

You'll also have to set up your VSFTPD server to make incoming anonymous FTP connections log in to the /data/network-install/RPM directory by default. You will also want to enable the correct logging. Here is a sample snippet of the vsftpd.conf file. Remember to restart VSFTPD to make these settings take effect

#
# File: vsftpd.conf
#

#
# Anonymous FTP Root Directory
#

anon_root=/data/network-install/RPM

#
# Log file definition
#

xferlog_enable=YES
xferlog_file=/var/log/vsftpd.log

Create A Special FTP User

You can also create a special user for non anonymous FTP installations with its home directory as "/". You must also make sure that the user has read access to the /data/network-install directory. An example is below.

[root@bigboy tmp]# useradd -g users ftpinstall
[root@bigboy tmp]# passwd ftpinstall
Changing password for user ftpinstall.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.
[root@bigboy tmp]#
[root@bigbot tmp]# usermod -d / ftpinstall
[root@bigbot tmp]#

Setup Your NFS Server

The steps for setting up an NFS server are more complicated.

1) Create a /etc/exports file with the following entry in it. You must use tabs, not spaces between the entries

/data/network-install    *(ro,sync)

2) Make sure that the portmap, nfs, nfslock and netfs daemons are all running to create an NFS server. The startup scripts for these are found in the /etc/init.d directory. Chapter 29, "Remote Disk Access with NFS", will explain this in more detail.

3) Run the exportfs command to add this directory to the NFS database of network available directories.

[root@bigboy tmp]# exportfs -ra

4) The installation client must have a matching pair of forward and reverse DNS entries on your DNS server. In other words, a DNS lookup on the IP address of the installation client must return a server name that will map back to the original IP address when a DNS lookup is done on that same server name.

[root@bigboy tmp]# host 192.168.1.96
96.1.168.192.in-addr.arpa domain name pointer 192-168-1-96.my-site.com.
[root@bigboy tmp]#
 
[root@bigboy tmp]# host 192-168-1-96.my-site.com
192-168-1-96.my-site.com has address 192.168.1.96
[root@bigboy tmp]#

This may mean that you will have to create entries for all your DHCP IP addresses if you choose to use a DHCP method of assigning IP addresses during installation.

Configure Your DHCP Server

During the installation procedure, the installation client will prompt you for the IP address it should use for the installation process. I recommend selecting the option that makes the Installation Client get its address via DHCP. This will automate the installation more and will therefore make it faster. It will also reduce the possibility of human error.

Setting up the Installation Server as a DHCP server is fairly straight forward and can be found in Chapter 8, "Configuring the DHCP Server".

Creating A Boot CD

You will also need the first CD in your set of Fedora CDs will work. You can either copy an existing disk, or burn a copy of the FC2-i386-disc1.iso file onto a CD.

The Network Installation

From here on, the installation procedure mimics the regular Linux installation, except for the first couple steps.

1) Connect your client Linux box to the DHCP network.

2) Boot your system using the first Fedora installation CD. This is the only CD you'll need for future network installations.

3) Enter the command "linux askmethod" at the boot: prompt

4) Hit the <Enter> key

5) Go through the usual steps until it prompts for the "Installation Method". You will see a number of choices

Local CDROM
Hard Drive
NFS Image
FTP
HTTP

6) Select the network option of your choice (NFS, FTP, HTTP)

7) Select the Ethernet device to which the installation client is connected to the installation server network. This would most likely be interface "eth0".

8) Select "DHCP" in the following "Configure TCP/IP" screen. This will make the Installation client use DHCP during the installation.

If You Selected The NFS Method

You will now reach the "NFS setup" menu. Enter the IP address of the installation server as the "NFS Server Name". The "Red Hat directory" will be "/data/network-install/ISO". The following menus will be the usual Fedora GUI installation screens.

If You Selected The HTTP Method

You will now reach the "HTTP Setup" menu. Enter the IP address of the installation server when prompted for a "Web site name".The "Red Hat directory" will be /network-install. The following menus will be text based versions of the usual Fedora installation screens.

During the installation, issue the following command on the server to check the Apache logs. It will help to verify whether the kickstart client is accessing the files correctly. You should get a status code of 200<code> after each GET statement. You should retrace your steps if you are not.

[root@bigboy tmp]# tail -f /var/log/httpd/access_log
192.168.1.247 - - [12/Nov/2006:12:01:04 -0800] "GET /network-install/RPM/repodata/repomd.xml HTTP/1.1" 200 1140 "-" "urlgrabber/2.9.9"
192.168.1.247 - - [12/Nov/2006:12:01:05 -0800] "GET /network-install/RPM/repodata/primary.xml.gz HTTP/1.1" 200 844228 "-" "urlgrabber/2.9.9"
192.168.1.247 - - [12/Nov/2006:12:01:19 -0800] "GET /network-install/RPM/repodata/comps.xml HTTP/1.1" 200 853899 "-" "urlgrabber/2.9.9"

[root@bigboy ~]# tail -f /var/log/vsftpd.log 
Sun Nov 12 20:53:12 2006 1 192.168.1.231 1140 /data/network-install/RPM/repodata/repomd.xml b _ o r ftp-install ftp 0 * c
Sun Nov 12 20:53:21 2006 2 192.168.1.231 844228 /data/network-install/RPM/repodata/primary.xml.gz b _ o r ftp-install ftp 0 * c
Sun Nov 12 20:53:40 2006 2 192.168.1.231 853899 /data/network-install/RPM/repodata/comps.xml b _ o r ftp-install ftp 0 * c

• The installation logs can always be viewed by hitting <CTRL-ALT-F3>
• Kernel messages can be seen by hitting <CTRL-ALT-F4>
• Access to a limited BASH shell Kernel can be gained by hitting <CTRL-ALT-F2>
• You can return to the main installation screen at any time by hitting <CTRL-ALT-F1> for text based installations and <CTRL-ALT-F7> when the GUI is used.
• Examine your server's <code>/var/log/httpd/access_log, /var/log/httpd/error_log files for the HTTP method; the /var/log/vsftpd.log file for the FTP method; and your /var/log/messages file for the NFS method.

Automating Installation With Kickstart

Both Fedora and RedHat Linux save all the parameters you used during installation in the /root/anaconda-ks.cfg kickstart configuration file. You can use this file to create an automated installation of a duplicate system which can be useful if you have a large number of servers to install.

This section shows you how to automate network installations using the kickstart application and NFS. You can use HTTP and FTP but they have been omitted to keep the discussion brief.

How To Create New Kickstart Configuration Files

You can create a customized kickstart configuration file by using the "ksconfig" command from a GUI console. It will bring up a menu from which you can select all your installation options. When finished, you save the configuration with the filename of your choice.

You may want to then edit the configuration file and comment out certain parameters that may change from system to system with a "#". These could include things like the system's name and IP address. During the kickstart process you will be prompted for these unspecified values.

Note: Do not change the order of the entries in the kickstart configuration file.

Note: The IP address you assign must be on the same subnet as that of the DHCP server for kickstart to work. If the server is going to reside on a different network after the installation, then you'll have to run a separate script to change the IP addressing information after the installation is complete.

Adding Post Installation Commands

You may want to run some commands on the newly created Linux installation after kickstart is complete. Some processes that are activated by default by Fedora may not be suitable for your server and may need to be disabled.

This can be done by placing a %post section at the end of the kicksrart file with all the post installation commands you wish to run. Here is an example:

%post
chkconfig isdn off
chkconfig pcmcia off
chkconfig portmap off
chkconfig apmd off
chkconfig nfslock off
chkconfig nfs off

A Note About Using anaconda-ks.cfg

It is possible to use the /root/anaconda-ks.cfg file as a template for future installations. RedHat comments out the partitioning information in this file, so you will either have to uncomment it and then make your partitioning modifications or be prepared to be prompted for your portioning information.

How To Run A Kickstart Installation

It is best to place your kickstart files in a subdirectory under the /data/network-install directory. The examples below assume the subdirectory is called /data/network-install/kickstart.

Remember that you may want to remove the "#" comments from the partition section of the file. If not, you will be prompted for this information.

Using a NFS Server

Verify that the first two lines of the file look like this or else you may be prompted for NFS ISO file location information.

install
nfs --server=192.16.1.100 --dir=/data/network-install/ISO

Using a Web Server

Verify that the first two lines of the file look like this or else you may be prompted for RPM base file location information.

install
url --url http://192.168.1.100/network-install/RPM

Booting With Your Kickstart Files

There are two ways to specify the name of the kickstart file to use. The first is to enter it manually from the LILO boot: prompt when you insert the boot CD. The second is to have your DHCP server automatically tell the Kickstart client about the name of the kickstart file to use when it assigns the IP address. Both methods are listed below:

Manually Specifying the Kickstart Filename

Once you have booted from your boot CDROM, you'll need to use the following command at the lilo boot: prompt to continue with the installation. The ks.cfg file is the kickstart configuration file we want to use.

NFS Method

boot: linux ks=nfs:192.168.1.100:/kickstart/ks.cfg

HTTP Method

boot: linux ks=http://192.168.1.100/network-install/kickstart/ks.cfg

Configuring The Filename Automatically

Whenever you have to create lots of cloned Linux servers, then you may want to configure your DHCP server to specify the single kickstart configuration file you wish to use. Here is how it's done:

1) Place your kickstart file in the /data/network-install/kickstart directory.

2) Edit your dhcpd.conf file and add the following lines to the section for the interface that will be serving DHCP IP addresses. The next-server value is the IP address of the kickstart server.

filename "/data/network-install/kickstart/ks.cfg";
next-server 192.168.1.100;

3) Insert the boot CD into the kickstart client Linux box and connect it to the DHCP network. At the boot: prompt type in the following command:

boot: linux ks

Kickstart will first search for a configuration file named ks.cfg on either the boot CD. It will then automatically attempt to get a DHCP IP address and see if the DHCP server will specify a configuration file.

Kickstart will then use NFS to get both the configuration file and the installation ISOs. The rest should be automatic.

Conclusion

The Kickstart method of Fedora Linux installation can greatly reduce the length of time it takes to install the operating system. Time is saved not only because a network connection can be faster than using CDs, but also because it can be left unattended to install a predetermined Linux configuration. A Kickstart server connected to an isolated wireless network dedicated to the purpose may be a good idea for data centers with hundreds of Linux servers.

A recent standard called PXE allows you to run kickstart without a CD ROM if you configure the NIC card to do a network boot from a specially configured DHCP server. The topic is beyond the scope of this book, but it may be interesting for readers with more complex projects to research this option more.