Linux系统默认yum为美国节点，可更换为阿里云yum提高下载速度：

为了在CentOS系统上更换为阿里云的YUM源，你需要按照以下步骤操作：

1. 备份当前的YUM源配置文件。
2. 删除或重命名 /etc/yum.repos.d 目录下的其他.repo文件。
3. 下载阿里云的CentOS YUM源配置文件。
4. 运行YUM源更新命令。

以下是具体的命令：

bash# 1. 备份当前的YUM源配置文件
sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

# 2. 下载阿里云的CentOS YUM源配置文件
sudo curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

# 3. 运行YUM源更新命令
sudo yum clean all
sudo yum makecache

确保替换的YUM源配置文件中的版本与你的CentOS版本相匹配。如果你使用的是CentOS 8，那么应该下载对应的阿里云CentOS 8 YUM源配置文件。

Ubuntu更换阿里云软件源

1. 备份

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

2.修改

sudo vim /etc/apt/sources.list

将source.list文件内容替换成下面的

deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse

3. 更新

sudo apt-get update