需要更换到国内阿里云镜像

//备份本地源
cp /etc/apt/sources.list /etc/apt/sources.list.bak
vim /etc/apt/sources.list
//备份本地源
cp /etc/apt/sources.list /etc/apt/sources.list.bak
vim /etc/apt/sources.list

ubuntu安装yum失败 ：E: Unable to locate package yum 问题解决_vim

#国内镜像
deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

替换完成后

sudo apt-get clean all
sudo apt-get update

更新的时候报错：Err:1 http://mirrors.aliyun.com/ubuntu bionic InRelease The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 3B4FE6ACC0B21F32

ubuntu安装yum失败 ：E: Unable to locate package yum 问题解决_本地源_02

更换源之后需要添加公钥，执行以下命令：

注意：这里的recv-keys就是报错中的key，粘贴过来即可

公钥：3B4FE6ACC0B21F32（报错的公钥）

apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 公钥

ubuntu安装yum失败 ：E: Unable to locate package yum 问题解决_本地源_03

此时再次执行:

sudo apt-get update
sudo apt-get install yum

开始安装yum

ubuntu安装yum失败 ：E: Unable to locate package yum 问题解决_本地源_04

到了这一步就安装成功了，验证下是否可用

ubuntu安装yum失败 ：E: Unable to locate package yum 问题解决_ubuntu_05