从上图中可以看到源不通或者失效，所以才会有”E: Some index files failed to download, they have been ignored, or old ones used instead.”的错误提示问题，那我们如何解决问题呢？

如果我们也是Debian环境，那就修改阿里云源，这样可以解决这个问题，当然还有其他源比如163等，我们用户不管了，谁好用老左就用哪个。

第一、替换文件

vim /etc/apt/sources.list

第二、替换源内容

常用安装源站点列表

163镜像站

deb http://mirrors.163.com/debian/ buster main non-free contrib
deb http://mirrors.163.com/debian/ buster-updates main non-free contrib
deb http://mirrors.163.com/debian/ buster-backports main non-free contrib
deb http://mirrors.163.com/debian-security/ buster/updates main non-free contrib

deb-src http://mirrors.163.com/debian/ buster main non-free contrib
deb-src http://mirrors.163.com/debian/ buster-updates main non-free contrib
deb-src http://mirrors.163.com/debian/ buster-backports main non-free contrib
deb-src http://mirrors.163.com/debian-security/ buster/updates main non-free contrib

华为云镜像站

deb https://mirrors.huaweicloud.com/debian/ buster main contrib non-free
deb https://mirrors.huaweicloud.com/debian/ buster-updates main contrib non-free
deb https://mirrors.huaweicloud.com/debian/ buster-backports main contrib non-free
deb https://mirrors.huaweicloud.com/debian-security/ buster/updates main contrib non-free

deb-src https://mirrors.huaweicloud.com/debian/ buster main contrib non-free
deb-src https://mirrors.huaweicloud.com/debian/ buster-updates main contrib non-free
deb-src https://mirrors.huaweicloud.com/debian/ buster-backports main contrib non-free

腾讯云镜像站

deb http://mirrors.cloud.tencent.com/debian/ buster main non-free contrib
deb http://mirrors.cloud.tencent.com/debian-security buster/updates main
deb http://mirrors.cloud.tencent.com/debian/ buster-updates main non-free contrib
deb http://mirrors.cloud.tencent.com/debian/ buster-backports main non-free contrib

deb-src http://mirrors.cloud.tencent.com/debian-security buster/updates main
deb-src http://mirrors.cloud.tencent.com/debian/ buster main non-free contrib
deb-src http://mirrors.cloud.tencent.com/debian/ buster-updates main non-free contrib
deb-src http://mirrors.cloud.tencent.com/debian/ buster-backports main non-free contrib

中科大镜像站

deb https://mirrors.ustc.edu.cn/debian/ buster main contrib non-free
deb https://mirrors.ustc.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirrors.ustc.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirrors.ustc.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirrors.ustc.edu.cn/debian/ buster main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian-security/ buster/updates main contrib non-free

阿里云镜像站

deb http://mirrors.aliyun.com/debian/ buster main non-free contrib
deb http://mirrors.aliyun.com/debian-security buster/updates main
deb http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib
deb http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib

deb-src http://mirrors.aliyun.com/debian-security buster/updates main
deb-src http://mirrors.aliyun.com/debian/ buster main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ buster-updates main non-free contrib
deb-src http://mirrors.aliyun.com/debian/ buster-backports main non-free contrib

清华大学镜像站

deb https://mirrors.tuna.tsinghua.edu.cn/debian/ buster main contrib non-free
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirrors.tuna.tsinghua.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ buster main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security/ buster/updates main contrib non-free

兰州大学镜像站

deb http://mirror.lzu.edu.cn/debian stable main contrib non-free
deb http://mirror.lzu.edu.cn/debian stable-updates main contrib non-free
deb http://mirror.lzu.edu.cn/debian/ buster-backports main contrib non-free
deb http://mirror.lzu.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src http://mirror.lzu.edu.cn/debian stable main contrib non-free
deb-src http://mirror.lzu.edu.cn/debian stable-updates main contrib non-free
deb-src http://mirror.lzu.edu.cn/debian/ buster-backports main contrib non-free
deb-src http://mirror.lzu.edu.cn/debian-security/ buster/updates main contrib non-free

上海交大镜像站

deb https://mirror.sjtu.edu.cn/debian/ buster main contrib non-free
deb https://mirror.sjtu.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirror.sjtu.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirror.sjtu.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirror.sjtu.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirror.sjtu.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirror.sjtu.edu.cn/debian/ buster main contrib non-free
deb-src https://mirror.sjtu.edu.cn/debian-security/ buster/updates main contrib non-free

附上官方全球镜像站列表地址：https://www.debian.org/mirror/list