LINUX Loaded plugins: fastestmirror Repodata is over 2 weeks old. Install yum-cron? Or run: yum make

Loaded plugins: fastestmirror
Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast
Existing lock /var/run/yum.pid: another copy is running as pid 4334.
Another app is currently holding the yum lock; waiting for it to exit...
  The other application is: yum
    Memory :  23 M RSS (414 MB VSZ)
    Started: Sun May  3 09:51:08 2020 - 23:47 ago
    State  : Traced/Stopped, pid: 4334

依次执行操作，直到错误解决为止：

1、根据提示执行：yum makecache fast

2、yum clean all

3、yum update

4、ps aux|grep yum

5、kill -9 yum进程号

6、更换yum源文件：

1）cd /etc/yum.repos.d

2） wget http://mirrors.163.com/.help/CentOS7-Base-163.repo

3） mv CentOS-Base.repo CentOS-Base.repo.bak

4）mv CentOS7-Base-163.repo CentOS-Base.repo