存在隐患 : 3 racks are required for the erasure coding policies: RS-6-3-1024k. The number of racks is on

刚装的CDH6.2.1版本的集群

172.30.81.203 manager
172.30.81.204 node1
172.30.81.205 node2
172.30.81.206 node3

存在隐患：9 DataNodes are required for the erasure coding policies: RS-6-3-1024k.The number of DataNodes is only 3.
9 DataNodes are required for the erasure coding policies RS-

解决方案

使用RS-6-3-1024k编码纠删码策略至少需要9个DataNodes，当前只安装了3个，所以再增加6个DataNodes节点即可解决该问题。
修改编码纠删码策略同样也可以解决，不过会比较麻烦

补充：

纠删码基本操作

1. 查看当前支持的纠删码策略

命令如下

hdfs ec -listPolicies

9 DataNodes are required for the erasure coding policies RS-

查看Hadoop版本命令：hadoop version

9 DataNodes are required for the erasure coding policies