【转】ubuntu 11.04使用apt-get安装软件时一直提示E:unable to locate package

问题：

VMware虚拟机安装了ubuntu 11.04，在使用apt-get安装软件时一直提示E：Unable to locate package。
百度了原因，说是要更新源，使用命令：sudo apt-get update更新了，但更新之后问题还是存在；



解决方案：

主要还是源的问题，目前网上找的很多源都是很久以前的了，很多的可能都不能用了； 然后自己重新下载了一个ubuntu 14.04版本的源替换原来的sources.list文件，然后运行sudo apt-get update更新后就可以安装软件了。

更新源地址（这是Ubuntu 14.04的/etc/apt/source.list文件的内容）：
#deb cdrom:[Ubuntu 14.04 LTS _Trusty Tahr_ - Release amd64 (20140417)]/ trusty main restricted

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to

# newer versions of the distribution.

deb http://us.archive.ubuntu.com/ubuntu/ trusty main restricted

deb-src http://us.archive.ubuntu.com/ubuntu/ trusty main restricted

## Major bug fix updates produced after the final release of the

## distribution.

deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates main restricted

deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu

## team. Also, please note that software in universe WILL NOT receive any

## review or updates from the Ubuntu security team.

deb http://us.archive.ubuntu.com/ubuntu/ trusty universe

deb-src http://us.archive.ubuntu.com/ubuntu/ trusty universe

deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe

deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu

## team, and may not be under a free licence. Please satisfy yourself as to

## your rights to use the software. Also, please note that software in

## multiverse WILL NOT receive any review or updates from the Ubuntu

## security team.

deb http://us.archive.ubuntu.com/ubuntu/ trusty multiverse

deb-src http://us.archive.ubuntu.com/ubuntu/ trusty multiverse

deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates multiverse

deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates multiverse

## N.B. software from this repository may not have been tested as

## extensively as that contained in the main release, although it includes

## newer versions of some applications which may provide useful features.

## Also, please note that software in backports WILL NOT receive any review

## or updates from the Ubuntu security team.

deb http://us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse

deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu trusty-security main restricted

deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted

deb http://security.ubuntu.com/ubuntu trusty-security universe

deb-src http://security.ubuntu.com/ubuntu trusty-security universe

deb http://security.ubuntu.com/ubuntu trusty-security multiverse

deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse

## Uncomment the following two lines to add software from Canonical's

## 'partner' repository.

## This software is not part of Ubuntu, but is offered by Canonical and the

## respective vendors as a service to Ubuntu users.

# deb http://archive.canonical.com/ubuntu trusty partner

# deb-src http://archive.canonical.com/ubuntu trusty partner

## This software is not part of Ubuntu, but is offered by third-party

## developers who want to ship their latest software.

deb http://extras.ubuntu.com/ubuntu trusty main

deb-src http://extras.ubuntu.com/ubuntu trusty main

修改Ubuntu系统源的方法：

1、更源的保存文件的权限，在终端中执行下面的命令：

chmod 777 /etc/apt/sources.list

2、打开源文件

在终端中执行下面的命令：

gedit /etc/apt/sources.list

喜欢vi的朋友可以用下面的命令:

vi /etc/apt/sources.list

3、把上面给出的Ubuntu 14.04的源复制到sources.list文件中保存退出，其中以 # 号开头的表示注释，可以一起复制，不会出错。

4、在终端中执行下面的命令：

sudo apt-get update

5、关于添加源后Dynamic MMap ran out of room. Please increase the size of APT::Cache-Limit.*****错误的解决办法：

　　a、在终端中输入命令： vi apt.conf

　　b、然后加入如下内容 :

　　　　APT

　　　　{

　　　　　　Cache-Limit 67108864;

　　　　};

　　c、保存退出，再次apt-get update，问题应该就可以解决了，若是你添加的源更多，可能还会报错，那么可以再把67108864这个数值改大，

　　主要原因是默认的缓存不够，需要手动设置apt.conf 文件， 在这里设置了64mb

　　注：若是没有apt.conf，那么就需要新建apt.conf文件，新建文件之后再执行以上操作。

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