文章目录

前言1、命令简单描述2、本地问题log3、原因分析4、解决方法4.1、系统网络问题【本问题解决方案】4.2、ubuntu18.04 自带的源`/etc/apt/sources.list`有问题4.2.1、解决方案：替换源`/etc/apt/sources.list`4.2.2、如果替换源`/etc/apt/sources.list`后还是不行 5、apt-get update成功log

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前言

在执行 sudo apt-get install 安装新软件包或升级现有软件包之前，通常会建议先运行 sudo apt-get update，以确保你安装的是最新版本。

但是往往敲完sudo apt-get update命令，会出现超时一段时间后报错结束的问题。

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1、命令简单描述

apt-get

是 Debian 和 Ubuntu 系统上用于包管理的一个工具，而其他 Linux 发行版可能使用不同的包管理工具（如 yum、zypper等）。

update

update 是同步 /etc/apt/sources.list 和 /etc/apt/sources.list.d 中列出的源的索引，这样才能获取到最新的软件包。

upgrade

upgrade 是升级已安装的所有软件包，升级之后的版本就是本地索引里的。 因此，在执行 upgrade 之前一定要执行 update，这样才能是最新的。

#新添加beginnameserver 8.8.8.8nameserver 8.8.4.4#新添加endnameserver 127.0.0.53options edns0

Esc取消编辑模式，:wq!保存编辑退出，执行cat命令查看是否编辑成功

sudo cat /etc/resolv.conf

之后执行sudo apt-get update就正常了。

2、本地问题log

root@ubuntu:~# sudo apt updateErr:1 http://mirrors.ustc.edu.cn/ubuntu-ports bionic InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'Err:2 http://mirrors.ustc.edu.cn/ubuntu-ports bionic-updates InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'Err:3 http://mirrors.ustc.edu.cn/ubuntu-ports bionic-backports InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'Err:4 http://mirrors.ustc.edu.cn/ubuntu-ports bionic-security InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'Reading package lists... Done Building dependency tree Reading state information... DoneAll packages are up to date.W: Failed to fetch http://mirrors.ustc.edu.cn/ubuntu-ports/dists/bionic/InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'W: Failed to fetch http://mirrors.ustc.edu.cn/ubuntu-ports/dists/bionic-updates/InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'W: Failed to fetch http://mirrors.ustc.edu.cn/ubuntu-ports/dists/bionic-backports/InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'W: Failed to fetch http://mirrors.ustc.edu.cn/ubuntu-ports/dists/bionic-security/InRelease Temporary failure resolving 'mirrors.ustc.edu.cn'W: Some index files failed to download. They have been ignored, or old ones used instead.

3、原因分析

报错提示：

W: Some index files failed to download. They have been ignored, or old ones used instead.W: 一些索引文件下载失败。它们要么被忽略，要么使用旧的索引文件。

可以看出是网络原因。

主要是底下这两种原因导致的：

3.1、系统网络问题；【本问题解决方案】

3.2、ubuntu18.04 自带的源/etc/apt/sources.list有问题；

4、解决方法

4.1、系统网络问题【本问题解决方案】

解决方案：检查DNS配置

（1）Ubuntu 18.04 查看DNS命令：

sudo cat /etc/resolv.conf

root@ubuntu:~# cat /etc/resolv.conf# This file is managed by man:systemd-resolved(8). Do not edit.## This is a dynamic resolv.conf file for connecting local clients to the# internal DNS stub resolver of systemd-resolved. This file lists all# configured search domains.## Run "systemd-resolve --status" to see details about the uplink DNS servers# currently in use.## Third party programs must not access this file directly, but only through the# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,# replace this symlink by a static file or a different symlink.## See man:systemd-resolved.service(8) for details about the supported modes of# operation for /etc/resolv.conf.nameserver 127.0.0.53options edns0

（2）添加Google 提供的公共 DNS 服务器的 IP 地址 8.8.8.8。

两种方式添加：

第一种：直接在 /etc/resolv.conf 文件后面追加命令：

echo "nameserver 8.8.8.8" >> /etc/resolv.conf

第二种：修改文件 sudo vi /etc/resolv.conf，修改后的文件如下：

root@ubuntu:~# sudo vi /etc/resolv.conf # This file is managed by man:systemd-resolved(8). Do not edit.## This is a dynamic resolv.conf file for connecting local clients to the# internal DNS stub resolver of systemd-resolved. This file lists all# configured search domains.## Run "systemd-resolve --status" to see details about the uplink DNS servers# currently in use.## Third party programs must not access this file directly, but only through the# symlink at /etc/resolv.conf. To manage man:resolv.conf(5) in a different way,# replace this symlink by a static file or a different symlink.## See man:systemd-resolved.service(8) for details about the supported modes of# operation for /etc/resolv.conf.nameserver 127.0.0.53options edns0nameserver 8.8.8.8

（4）尝试 apt update 一下，速度快多了！

sudo apt-get update

4.2、ubuntu18.04 自带的源/etc/apt/sources.list有问题

4.2.1、解决方案：替换源/etc/apt/sources.list

（1）备份源列表

Ubuntu配置的默认源并不是国内的服务器，下载更新软件都比较慢。

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak

（2）打开 /etc/apt/sources.list 文件修改

sudo vim /etc/apt/sources.list

（3）在上面打开的文件开头添加（阿里源）就行

# 阿里源deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse# ubuntudeb http://cn.archive.ubuntu.com/ubuntu bionic-security main restricted# deb-src http://cn.archive.ubuntu.com/ubuntu bionic-security main restricteddeb http://cn.archive.ubuntu.com/ubuntu bionic-security universe# deb-src http://cn.archive.ubuntu.com/ubuntu bionic-security universedeb http://cn.archive.ubuntu.com/ubuntu bionic-security multiverse# deb-src http://cn.archive.ubuntu.com/ubuntu bionic-security multiverse

附记：（清华源）

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiversedeb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiversedeb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiversedeb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiversedeb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiversedeb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiversedeb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiversedeb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiversedeb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiversedeb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

（4）同样的尝试更新一下，速度快多了！

sudo apt-get update

4.2.2、如果替换源/etc/apt/sources.list后还是不行

把它们加入到了系统的源列表中后，sudo apt-get update还是不行。但是，所有停止维护的版本都可以使用 old 源。所以在原列表中把原来的地址改为带有 old 源的就可以了。

直接在前面加old-即可。

例如：

deb http://cn.archive.ubuntu.com/ubuntu bionic-security main restricted改为deb http://old-cn.archive.ubuntu.com/ubuntu bionic-security main restricted

5、apt-get update成功log

root@ubuntu:~# apt-get update

Hit:1 http://mirrors.ustc.edu.cn/ubuntu-ports bionic InRelease

Hit:2 http://mirrors.ustc.edu.cn/ubuntu-ports bionic-updates InRelease

Hit:3 http://mirrors.ustc.edu.cn/ubuntu-ports bionic-backports InRelease

Hit:4 http://mirrors.ustc.edu.cn/ubuntu-ports bionic-security InRelease

Reading package lists… Done

root@ubuntu:~# apt-get upgrade

Reading package lists… Done

Building dependency tree

Reading state information… Done

Calculating upgrade… Done

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

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