1.下载并安装yum-2.4.0-1.centos4.noarch.rpm文件，下载地址为：
ftp://ftp.pbone.net/mirror/ftp.centos.org/4.2/os/alpha/CentOS/RPMS/yum-2.4.0-1.centos4.noarch.rpm
2.修改或建立/etc/yum.repos.d/CentOS-Base.repo为如下内容：
QUOTE:
[base]
name=CentOS-$releasever - Base
baseurl=http://ftp.riken.jp/Linux/caos/centos/4.0/os/$basearch/
gpgcheck=1
#released updates
[update]
name=CentOS-$releasever - Updates
baseurl=http://ftp.riken.jp/Linux/caos/centos/4.0/updates/$basearch/
gpgcheck=1
#packages used/produced in the build but not released
[addons]
name=CentOS-$releasever - Addons
baseurl=http://ftp.riken.jp/Linux/caos/centos/4.0/addons/$basearch/
gpgcheck=1
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
baseurl=http://ftp.riken.jp/Linux/caos/centos/4.0/extras/$basearch/
gpgcheck=1
3.修改或建立/etc/yum.repos.d/dag.repo为如下内容：
QUOTE:
[dag]
name=Dag RPM Repository for RHEL4
baseurl=http://ftp.riken.jp/Linux/dag/redhat/el4/en/$basearch/dag/
enabled=1
gpgcheck=1
gpgkey=http://ftp.riken.jp/Linux/dag/packages/RPM-GPG-KEY.dag.txt
4.运行update:
yum update
5.升级：
yum upgrade
6.安装其它软件，例如：
yum install mplayer
提要：我们用的是Redhat/Fedora通过在线安装更新软件包，除了系统自带的up2date以外，我们还有更为强大的在线升级工具 yum 和 apt-get 可用。主要资源有 freshrpms.net和 rpm.livna.org ；
在本文中，我们主要解介绍 Fedora core 4.0 通过软件包管理工具yum来在线安装更新软件；关于apt工具应用，我们会在另外一篇中介绍；
一、 yum 的使用；
有些初学Linux的弟兄可能问，为什么不用系统自带的图形化工具up2date来升级，却要用 yum呢。其实大家用一用就知道了，up2date 真是奇慢无比，而且经常失去响应；造成机器假死的情况。所以我们还是试一试yum ；另外freshrpms.net 可能比官方站更快的更新升级源，也没有理由不用 yum；
1、首先我们要到下面的地址下载与自己系统相对应的版本的 yum；
http://ayo.freshrpms.net/
比如我用的是Fedora core 4.0 就下载如下的包安装；
QUOTE:
[root@localhost beinan]# rpm -ivh freshrpms-release-1.1-1.fc.noarch.rpm
warning: freshrpms-release-1.1-1.fc.noarch.rpm: Header V3 DSA signature: NOKEY, key ID e42d547b
Preparing... ########################################### [100%]
1:freshrpms-release ########################################### [100%]
2、安装软件举例；
比如我要安装能听mp3的 bmp-mp3，只要输入下面的命令行即可，系统就自己工作了；
[root@localhost beinan]# yum install bmp-mp3
内容全景如下：
QUOTE:
[root@localhost beinan]# yum install bmp-mp3
Setting up Install Process
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:00
freshrpms 100% |=========================| 951 B 00:00
Reading repository metadata in from local files
primary.xml.gz 100% |=========================| 42 kB 00:03
freshrpms : ################################################## 122/122
Added 122 new packages, deleted 0 old in 0.72 seconds
Parsing package install arguments
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Downloading header for bmp-mp3 to pack into transaction set.
bmp-mp3-0.9.7-1.2.fc4.i38 100% |=========================| 2.9 kB 00:00
---> Package bmp-mp3.i386 0:0.9.7-1.2.fc4 set to be updated
--> Running transaction check
--> Processing Dependency: libid3-3.8.so.3 for package: bmp-mp3
--> Processing Dependency: libbeep.so.2 for package: bmp-mp3
--> Processing Dependency: bmp >= 0.9.7 for package: bmp-mp3
--> Restarting Dependency Resolution with new changes.
--> Populating transaction set with selected packages. Please wait.
---> Downloading header for id3lib to pack into transaction set.
id3lib-3.8.3-11.fc4.i386. 100% |=========================| 38 kB 00:05
---> Package id3lib.i386 0:3.8.3-11.fc4 set to be updated
---> Downloading header for bmp to pack into transaction set.
bmp-0.9.7-10.fc4.i386.rpm 100% |=========================| 14 kB 00:03
---> Package bmp.i386 0:0.9.7-10.fc4 set to be updated
--> Running transaction check
Dependencies Resolved
=============================================================================
Package Arch Version Repository Size
=============================================================================
Installing:
bmp-mp3 i386 0.9.7-1.2.fc4 freshrpms 95 k
Installing for dependencies:
bmp i386 0.9.7-10.fc4 extras 912 k
id3lib i386 3.8.3-11.fc4 extras 752 k
Transaction Summary
=============================================================================
Install 3 Package(s)
Update 0 Package(s)
Remove 0 Package(s)
Total download size: 1.7 M
Is this ok [y/N]: y
Downloading Packages:
(1/3): id3lib-3.8.3-11.fc 100% |=========================| 752 kB 01:04
(2/3): bmp-0.9.7-10.fc4.i 100% |=========================| 912 kB 02:14
(3/3): bmp-mp3-0.9.7-1.2. 100% |=========================| 95 kB 00:05
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing: bmp ######################### [1/3]
Installing: id3lib ######################### [2/3]
Installing: bmp-mp3 ######################### [3/3]
Installed: bmp-mp3.i386 0:0.9.7-1.2.fc4
Dependency Installed: bmp.i386 0:0.9.7-10.fc4 id3lib.i386 0:3.8.3-11.fc4
Complete!
注：yum优点:软件包依赖关系自行解决，比如上面的，我们可以看到本来我们只安装的是bmp-mp3，结果yum 安装也安装了 id3lib ；bmp
二、yum的一点小用法；
1、查询软件包；
面对成千上万的软件，我们可能无从下手，有时也不知道它的文件名；这时就要用到查询；我们可以用 yum list 来列出yum升级源上的包有文件；然后我们再来查看 info
有以下几个组合可以用；比如；
[root@localhost beinan]# yum list |more
加上一个管道 |，然后 more 一下，就能把所有的包分页显示出来。然后按一下空格键就能看下一页了。在显示的软件列表中，会有软件名称、版本、是否安装等；仔细的看一下吧。熟悉了就好了。也没有什么难的。
QUOTE:
[root@localhost beinan]# yum list |more
Setting up repositories
Reading repository metadata in from local files
Installed Packages
4Suite.i386 1.0-8.b1 installed
Canna.i386 3.7p3-13 installed
Canna-devel.i386 3.7p3-13 installed
如果想知道软件的详细信息，可能得用上info参数了。比如：
用法：
[root@localhost beinan]# yum info 软件名
比如：
QUOTE:
[root@localhost beinan]# yum info bmp-mp3
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:00
freshrpms 100% |=========================| 951 B 00:00
Reading repository metadata in from local files
Installed Packages
Name : bmp-mp3
Arch : i386
Version: 0.9.7
Release: 1.2.fc4
Size : 234 k
Repo : freshrpms
Summary: MP3 playback plugin for the Beep Media Player
Description:
This package contains an MP3 playback plugin for BMP (Beep Media Player),
a media player that uses a skinned user interface based on Winamp 2.x skins,
and is based on ("forked off") XMMS.
在上面的例子中，如果Repo : freshrpms是这样的，表示您的系统没有安装这个软件，如果显示的是：Repo : installed，表示已经安装了。
查询软件包，也可以再加参数 grep ，比如我们想查询升级源上是否有内核的新版本，则我们可以用下面的命令查询；当然您也可以用 [root@localhost beinan]# yum search kernel |more ，也就是yum --help提供的参数，也是一样的；
[root@localhost beinan]# yum list |grep kernel
我们看一下机器工作的结果，如下：
QUOTE:
[root@localhost beinan]# yum list |grep kernel
GFS-kernel.i686 2.6.11.8-20050601.1526 installed
cman-kernel.i686 2.6.11.5-20050601.1526 installed
dlm-kernel.i686 2.6.11.5-20050601.1526 installed
gnbd-kernel.i686 2.6.11.2-20050420.1331 installed
kernel.i686 2.6.11-1.1369_FC4 installed
kernel-devel.i686 2.6.11-1.1369_FC4 installed
kernel-doc.noarch 2.6.11-1.1369_FC4 installed
GFS-kernel.i586 2.6.11.8-20050601.1526 base
GFS-kernel-debuginfo.i686 2.6.11.8-20050601.1526 updates-released
GFS-kernel-debuginfo.i586 2.6.11.8-20050601.1526 updates-released
GFS-kernel-smp.i686 2.6.11.8-20050601.1526 base
GFS-kernel-xen0.i686 2.6.11.8-20050601.1526 base
GFS-kernel-xenU.i686 2.6.11.8-20050601.1526 base
cman-kernel.i586 2.6.11.5-20050601.1526 updates-released
cman-kernel.i686 2.6.11.5-20050601.1526 updates-released
cman-kernel-debuginfo.i586 2.6.11.5-20050601.1526 updates-released
cman-kernel-debuginfo.i686 2.6.11.5-20050601.1526 updates-released
cman-kernel-smp.i686 2.6.11.5-20050601.1526 updates-released
cman-kernel-xen0.i686 2.6.11.5-20050601.1526 updates-released
cman-kernel-xenU.i686 2.6.11.5-20050601.1526 updates-released
dlm-kernel.i686 2.6.11.5-20050601.1526 updates-released
dlm-kernel.i586 2.6.11.5-20050601.1526 updates-released
dlm-kernel-debuginfo.i586 2.6.11.5-20050601.1526 updates-released
dlm-kernel-debuginfo.i686 2.6.11.5-20050601.1526 updates-released
dlm-kernel-smp.i686 2.6.11.5-20050601.1526 updates-released
dlm-kernel-xen0.i686 2.6.11.5-20050601.1526 updates-released
dlm-kernel-xenU.i686 2.6.11.5-20050601.1526 updates-released
gnbd-kernel.i686 2.6.11.2-20050420.1331 updates-released
gnbd-kernel.i586 2.6.11.2-20050420.1331 updates-released
gnbd-kernel-debuginfo.i586 2.6.11.2-20050420.1331 updates-released
gnbd-kernel-debuginfo.i686 2.6.11.2-20050420.1331 updates-released
gnbd-kernel-smp.i686 2.6.11.2-20050420.1331 updates-released
gnbd-kernel-xen0.i686 2.6.11.2-20050420.1331 updates-released
gnbd-kernel-xenU.i686 2.6.11.2-20050420.1331 updates-released
kernel.i586 2.6.12-1.1398_FC4 updates-released
kernel.i686 2.6.12-1.1398_FC4 updates-released
kernel-debuginfo.i686 2.6.12-1.1398_FC4 updates-released
kernel-debuginfo.i586 2.6.12-1.1398_FC4 updates-released
kernel-devel.i586 2.6.12-1.1398_FC4 updates-released
kernel-devel.i686 2.6.12-1.1398_FC4 updates-released
kernel-doc.noarch 2.6.12-1.1398_FC4 updates-released
kernel-smp.i686 2.6.12-1.1398_FC4 updates-released
kernel-smp-devel.i686 2.6.12-1.1398_FC4 updates-released
kernel-xen0.i686 2.6.12-1.1398_FC4 updates-released
kernel-xen0-devel.i686 2.6.12-1.1398_FC4 updates-released
kernel-xenU.i686 2.6.12-1.1398_FC4 updates-released
kernel-xenU-devel.i686 2.6.12-1.1398_FC4 updates-released
上面的确显示出一大堆与内核有关的， installed表示我们的系统已经安装了；
咱们看前一列吧，看一下名字就能猜个差不多；比如 doc 肯定和内核文档有关了；smp是多处理器的内核；其它的我不懂了，请想知道的弟兄用 info来看吧。
比如我们用的机器是单处理器的X86机，想看一下是否有新内核可用。所以咱们试一下下面的这个。看是否已经有了新内核可以升级的；
QUOTE:
[root@localhost beinan]# yum info kernel.i686
[root@localhost beinan]# yum info kernel.i686
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:00
freshrpms 100% |=========================| 951 B 00:00
Reading repository metadata in from local files
Installed Packages
Name : kernel
Arch : i686
Version: 2.6.11
Release: 1.1369_FC4
Size : 37 M
Repo : installed
Summary: Linux 内核(Linux 操作系统的核心)。
Description:
kernel 软件包包含 Linux 内核 (vmlinuz)，Red Hat Linux
操作系统的核心。内核处理操作系统的基本功能：
分配内存、处理分配、设备的输入和输出等等。
Available Packages
Name : kernel
Arch : i686
Version: 2.6.12
Release: 1.1398_FC4
Size : 14 M
Repo : updates-released
Summary: The Linux kernel (the core of the Linux operating system)
Description:
The kernel package contains the Linux kernel (vmlinuz), the core of any
Linux operating system. The kernel handles the basic functions
of the operating system: memory allocation, process allocation, device
input and output, etc.
通过上面的信息，我们可以看到 2.6.11的是已经安装了，因为已经显示的是Repo : installed ，下面还有一个Version: 2.6.12 ，告诉我们是Repo : updates-released，看来这个是升级用的了。
所以是否升级就看我们的了。
[root@localhost beinan]# yum update kernel
升级内核全景如下：
QUOTE:
[root@localhost beinan]# yum update kernel
Setting up Upgrade Process
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:00
freshrpms 100% |=========================| 951 B 00:00
Reading repository metadata in from local files
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Downloading header for kernel to pack into transaction set.
kernel-2.6.12-1.1398_FC4. 100% |=========================| 174 kB 00:18
---> Package kernel.i686 0:2.6.12-1.1398_FC4 set to be installed
--> Running transaction check
Dependencies Resolved
=============================================================================
Package Arch Version Repository Size
=============================================================================
Installing:
kernel i686 2.6.12-1.1398_FC4 updates-released 14 M
Transaction Summary
=============================================================================
Install 1 Package(s)
Update 0 Package(s)
Remove 0 Package(s)
Total download size: 14 M
Is this ok [y/N]:
是不是升级，只需要在 Is this ok [y/N]:行的后面输入y或者N；y是yes，就是点头同意的意思；N就是摇头No的意思。
对于软件包的查询，还有，比如：
QUOTE:
[root@localhost beinan]# yum list available 列出所有升级源上的包；
[root@localhost beinan]# yum list updates 列出所有升级源上的可以更新包；
[root@localhost beinan]# yum list installed 列出已经安装的包；
yum 的命令支持通配符； 比如；
QUOTE:
[root@localhost beinan]# yum list mp* |more
Setting up repositories
Reading repository metadata in from local files
Installed Packages
mpage.i386 2.5.4-5 installed
Available Packages
mpc.i386 0.11.2-3 extras
mpeg2dec.i386 0.4.0-5b.2.fc4 freshrpms
mpeg2dec-devel.i386 0.4.0-5b.2.fc4 freshrpms
mpg321.i386 0.2.10-6.2.fc4 freshrpms
mplayer.i386 1.0-0.16.pre7.2.fc4 freshrpms
mplayer-docs.i386 1.0-0.16.pre7.2.fc4 freshrpms
mplayer-fonts.noarch 1.1-3.fc freshrpms
mplayer-skins.noarch 1.7-1.fc freshrpms
[root@localhost beinan]#
2.安装和升级软件包；
安装和升级分别是 install 和 update 参数；比如；
[root@localhost beinan]# yum update firefox
这样我们就可以升级 firefox了。
QUOTE:
[root@localhost beinan]# yum update firefox
Setting up Update Process
Setting up repositories
updates-released 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
base 100% |=========================| 1.1 kB 00:03
freshrpms 100% |=========================| 951 B 00:02
Reading repository metadata in from local files
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Package firefox.i386 0:1.0.6-1.1.fc4 set to be updated
--> Running transaction check
Dependencies Resolved
=============================================================================
Package Arch Version Repository Size
=============================================================================
Updating:
firefox i386 1.0.6-1.1.fc4 updates-released 18 M
Transaction Summary
=============================================================================
Install 0 Package(s)
Update 1 Package(s)
Remove 0 Package(s)
Total download size: 18 M
Is this ok [y/N]:
如果不加参数的 update 会是什么呢？？
[root@localhost beinan]# yum update
试着运行一下看看？会好长时间，对系统进行全面更新，我们要进行y和N了。
3.移除软件包要用到remove参数；比如；
[root@localhost beinan]# yum remove bmp-mp3
内容全景如下：
QUOTE:
[root@localhost beinan]# yum remove bmp-mp3
Setting up Remove Process
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Package bmp-mp3.i386 0:0.9.7-1.2.fc4 set to be erased
--> Running transaction check
Dependencies Resolved
=============================================================================
Package Arch Version Repository Size
=============================================================================
Removing:
bmp-mp3 i386 0.9.7-1.2.fc4 installed 234 k
Transaction Summary
=============================================================================
Install 0 Package(s)
Update 0 Package(s)
Remove 1 Package(s)
Total download size: 0
Is this ok [y/N]:
按y就移除了；
三、yum的图形工具；
请参见：《软件在线升级更新yum 图形工具介绍》
四、yum的帮助；
在论坛中有好多，有兴趣的弟兄自己找找看吧；但也不要忘记了自救；呵。。。。
QUOTE:
[root@localhost beinan]# yum --help
Usage: yum [options] <>
Options:
-c [config file] - specify the config file to use
-e [error level] - set the error logging level
-d [debug level] - set the debugging level
-y - answer yes to all questions
-R [time in minutes] - set the max amount of time to randomly run in
-C run from cache only - do not update the cache
--installroot=[path] - set the install root (default '/')
--version - output the version of yum
--exclude=package to exclude
--disablerepo=repository id to disable (overrides config file)
--enablerepo=repository id to enable (overrides config file)
-h, --help - this screen
还有更厉害的帮助；
[root@localhost beinan]#man yum
