参考资料:
VirtualBox 官方地址
不啰嗦：
cd /etc/yum.repos.d/
sudo wget https://download.virtualbox.org/virtualbox/rpm/el/virtualbox.repo
yum update -y && yum install -y VirtualBox-6.0
验证执行：(检查每一步是否正确)
[centos@ip-172-26-0-234 ~]$ cd /etc/yum.repos.d/
[centos@ip-172-26-0-234 yum.repos.d]$ ls
CentOS-Base.repo CentOS-CR.repo CentOS-Debuginfo.repo CentOS-fasttrack.repo CentOS-Media.repo CentOS-Sources.repo CentOS-Vault.repo epel-7.repo
[centos@ip-172-26-0-234 yum.repos.d]$ sudo wget https://download.virtualbox.org/virtualbox/rpm/el/virtualbox.repo
--2019-06-13 10:07:25-- https://download.virtualbox.org/virtualbox/rpm/el/virtualbox.repo
Resolving download.virtualbox.org (download.virtualbox.org)... 104.103.44.231
Connecting to download.virtualbox.org (download.virtualbox.org)|104.103.44.231|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 259 [text/plain]
Saving to: ‘virtualbox.repo’
100%[===========================================================================================================================>] 259 --.-K/s in 0s
2019-06-13 10:07:27 (42.6 MB/s) - ‘virtualbox.repo’ saved [259/259]
[centos@ip-172-26-0-234 yum.repos.d]$ ls
CentOS-Base.repo CentOS-Debuginfo.repo CentOS-Media.repo CentOS-Vault.repo virtualbox.repo
CentOS-CR.repo CentOS-fasttrack.repo CentOS-Sources.repo epel-7.repo
[centos@ip-172-26-0-234 yum.repos.d]$ yum update -y
[centos@ip-172-26-0-234 yum.repos.d]$ yum search VirtualBox-6.0
[centos@ip-172-26-0-234 yum.repos.d]$ yum install VirtualBox-6.0
