//注意：不要用9.04的老版本了，因为老版本的更新源大都不维护了。
可以直接下载一个最新版的ubuntu11,安装系统时选上ssh即可。
0、查看是否已安装ssh,执行ps -e|grep ssh 如果出现457 00：00：00 sshd 字样表示已有ssh服务无需再安装了。
否则执行sudo apt-get update
如果没有错误请直接执行第5步
如果出现大量failed to fetch,请按以下步骤执行，
1、备份Ubuntu源列表
sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup
2、修改更新源
sudo gedit /etc/apt/sources.list （打开Ubuntu源列表文件）
3、将下面的代码粘贴进去
#网易 Ubuntu 11.10 源
deb http://mirrors.163.com/ubuntu/ oneiric main universe restricted multiverse
deb-src http://mirrors.163.com/ubuntu/ oneiric main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ oneiric-security universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ oneiric-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ oneiric-proposed universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ oneiric-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ oneiric-updates universe main multiverse restricted
4、通知ubuntu启用新的更新源
sudo apt-get update
如果出错,检查下网络是否连通再执行
sudo apt-get update --fix-missing
5.安装ssh
sudo apt-get install openssh-server
7.启动服务试试：
sudo /etc/init.d/ssh start