这四个Linux版本都可以通过设置软件源而在线安装或升级软件。Debian和Ubuntu使用apt，Fedora使用yum而Mandriva使用urpm来执行这些操作。首先得选择合适的软件源。
对于Debian，建议使用ustc的源，修改/etc/apt/source.list文件如下：
deb http://debian.ustc.edu.cn/debian/
testing main non-free contrib
deb http://debian.ustc.edu.cn/debian-security/
testing/updates main non-free contrib
deb http://debian.ustc.edu.cn/debian-uo/ sid marillat ustc java misc
#deb http://ftp3.tsinghua.edu.cn/mirror/debian/debian testing main non-free contrib
#deb http://ftp3.tsinghua.edu.cn/mirror/debian/debian-security
testing/updates main non-free contrib
#deb http://ftp3.tsinghua.edu.cn/mirror/debian/debian-unofficial sid marillat ustc java misc
Debian的安装程序开始只安装了基本的软件包，要安装基本的Gnome系统，可以在命令行下输入：
apt-get install x-window-system-core gnome-core gdm xscreensaver
对于Ubuntu，建议使用Ubuntu中文站的源，修改/etc/apt/source.list文件如下：
deb http://archive.ubuntu.org.cn/ubuntu dapper main restricted universe multiverse
deb http://archive.ubuntu.org.cn/ubuntu dapper-security main restricted universe multiverse
deb http://archive.ubuntu.org.cn/ubuntu dapper-updates main restricted universe multiverse
deb http://archive.ubuntu.org.cn/ubuntu dapper-backports main universe multiverse restricted
deb http://archive.ubuntu.org.cn/ubuntu-cn dapper main universe multiverse restricted
deb http://archive.ubuntu.org.cn/ubuntu-cn
breezy main universe multiverse restricted
对于Fedora，首先修改yum的软件源，使用速度比较快的国内镜像。按照以下修改/etc/yum.repos.d目录的下面fedora-core.repo,fedora-extras.repo和fedora-updates.repo这几个文件：
#/etc/yum.repos.d/fedora-core.repo
[core]
name=Fedora Core $releasever - $basearch - Base
#baseurl=http://download.fedora.redhat.com/pub/fedora/linux/
core/$releasever/$basearch/os/
baseurl=ftp://ftp3.tsinghua.edu.cn/mirror/download.fedora.redhat.com/pub/
fedora/linux/core/$releasever/$basearch/os/
#baseurl=http://mirrors.geekbone.org/fedora/core/$releasever/$basearch/os/
#mirrorlist=http://fedora.redhat.com/download/mirrors/fedora-core-$releasever
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora file:///etc/pki/rpm-gpg/RPM-GPG-KEY
#/etc/yum.repos.d/fedora-extras.repo
[extras]
name=Fedora Extras $releasever - $basearch
#baseurl=http://download.fedora.redhat.com/pub/fedora/
linux/extras/$releasever/$basearch/
baseurl=ftp://ftp3.tsinghua.edu.cn/mirror/download.fedora.redhat.com/pub/fedora
/linux/extras/$releasever/$basearch/
#baseurl=http://mirrors.geekbone.org/fedora/extras/$releasever/$basearch/
#mirrorlist=http://fedora.redhat.com/download/mirrors/fedora-extras-$releasever
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-extras
gpgcheck=1
#/etc/yum.repos.d/fedora-updates.repo
[updates]
name=Fedora Core $releasever - $basearch - Released Updates
#baseurl=http://download.fedora.redhat.com/pub/fedora
/linux/core/updates/$releasever/$basearch/
baseurl=ftp://ftp3.tsinghua.edu.cn/mirror/download.fedora.redhat.com/pub
/fedora/linux/core/updates/$releasever/$basearch
#baseurl=http://mirrors.geekbone.org/fedora/core/updates/$releasever/$basearch/
#mirrorlist=http://fedora.redhat.com/download/mirrors/updates-released-fc$releasever
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora
然后建议加上freshrpms这个软件源(这个源包括了mp3插件，Mplayer，BmpX，aMule，unrar等等)。 首先以root用户运行如下命令导入密钥：
rpm --import http://freshrpms.net/RPM-GPG-KEY-freshrpms
然后在/etc/yum.repos.d目录里新建一个freshrpms.repo文件，内容如下：
[freshrpms]
name=Fedora Core $releasever - $basearch - Freshrpms
baseurl=ftp://ftp3.tsinghua.edu.cn/mirror/ayo.freshrpms.net/pub/freshrpms/ayo
/fedora/linux/$releasever/$basearch/freshrpms/
#baseurl=http://ayo.freshrpms.net/fedora/linux/$releasever/$basearch/freshrpms/
#mirrorlist=http://ayo.freshrpms.net/fedora/linux/$releasever/mirrors-freshrpms
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-freshrpms
最后建议加上livna这个软件源(这个源包括了MP3插件，Mplayer，Totem-xine，NTFS插件等等)。首先以root用户运行如下命令导入密钥：
rpm --import http://rpm.livna.org/RPM-LIVNA-GPG-KEY
然后在/etc/yum.repos.d目录里新建一个livna.repo文件，内容如下：
[livna]
name=Livna for Fedora Core $releasever - $basearch - Base
baseurl=
ftp://ftp3.tsinghua.edu.cn/mirro ... amp;ensp;$basearch/
http://rpm.livna.org/fedora/& ... amp;ensp;$basearch/
http://livna.cat.pdx.edu/fedora/ ... amp;ensp;$basearch/
http://wftp.tu-chemnitz.de/pub/l ... amp;ensp;$basearch/
http://ftp-stud.fht-esslingen.de ... amp;ensp;$basearch/
failovermethod=priority
#mirrorlist=http://rpm.livna.org/mirrorlist-5
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-LIVNA-GPG-KEY
对于Mandriva，建议使用Mandriva国内镜像的源，在控制台中输入如下命令行：
/etc/urpmi/urpmi.cfg
rm -rf /var/lib/urpmi/*
urpmi.addmedia --distrib ftp://202.38.75.11/FreeOS/MandrivaLinux/official/2006.0/i586/
urpmi.addmedia updates ftp://202.38.75.11/FreeOS/Mandri ... 006.0/main_updates/
urpmi.addmedia plf-free ftp://cooker@mirror.mandrakelinux.cn/plf/free/2006.0/
urpmi.addmedia plf-non-free ftp://cooker@mirror.mandrakelinux.cn/plf/non-free/2006.0/