报错具体内容：

[root@k8s-master ~]# systemctl start etcd
Job for etcd.service failed because a timeout was exceeded. See "systemctl status etcd.service" and "journalctl -xe" for details.
[root@k8s-master ~]# journalctl -xe
10月 20 11:16:35 k8s-master etcd[5334]: request cluster ID mismatch (got 5e546ead5830e8bd

解决办法：

步骤一：所有节点停止etcd服务  systemctl stop etcd

步骤二：所有节点清空etcd的ETCD_DATA_DIR目录数据   rm -rf /var/lib/etcd/*

步骤三：所有节点启动etcd服务  systemctl start etcd

到此问题解决。