下载依赖文件，离线安装
离线下载
### 下载到指定目录
$ sudo yum install <package-name> --downloadonly --downloaddir=/tmp
redis依赖包
yum install gcc-c++ --downloadonly --downloaddir=/data/downloads/redis
yum install centos-release-scl --downloadonly --downloaddir=/data/downloads/redis
yum install devtoolset-9-gcc devtoolset-9-gcc-c++ devtoolset-9-binutils --downloadonly --downloaddir=/data/downloads/redis
mysql依赖包
yum install perl perl-devel perl-Data-Dumper libaio-devel --downloadonly --downloaddir=/data/downloads/mysql
nginx依赖包
yum -y install gcc gcc-c++ kernel-devel --downloadonly --downloaddir=/data/downloads/nginx
yum -y install pcre-devel --downloadonly --downloaddir=/data/downloads/nginx
yum -y install openssl openssl-devel --downloadonly --downloaddir=/data/downloads/nginx
离线安装
# 因为部分rpm包互相依赖，只能用此方法安装。
rpm -ivh *.rpm --nodeps --force