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

1.rcp 

2.distcp   √    叢集節點間的拷貝

3.dcp

4.drcp 

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

No.

Hadoop環境可以同時讀，但不可以同時寫。它會自動獨佔模式來鎖定，不允許修改。

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

哪個HDFS命令是給本地檔案系統建立一個備份。

A.copyFromLocal

B.CopyFromLocal

C.CopyLocal

D.copyfromlocal

正確答案：A

第一個是不大寫的，記住！！