Reference https://www.jianshu.com/p/354f9fea9274
Mounted on a machine with a network, with good yum download the desired program, a network spread additional machine: Method a
the install xtrabackup --downloadonly --downloaddir = yum / rpmpath - xtrabackup installation package name - / rpmpath package placement path
Disadvantages: yum source because each machine is different, download the package, may be inconsistent, and another might not find the required version.