大数据选择题（二）

1.which among the following command is used to copy a directory from one node to another in HDFS?

1.rcp 

2.distcp   √    集群节点间的拷贝

3.dcp

4.drcp 

2.Can multiple clients write into an Hadoop HDFS file concurrently?

No.

Hadoop环境可以同时读，但不可以同时写。它会自动独占模式来锁定，不允许修改。

3.The HDFS command to create the copy of a file form a local system is which of the following?

哪个HDFS命令是给本地文件系统创建一个备份。

A.copyFromLocal

B.CopyFromLocal

C.CopyLocal

D.copyfromlocal

正确答案：A

第一个是不大写的，记住！！