HDFS Capacity: how to read “dfsadmin report”

问题

I am using Hadoop 2.6.0. When I run "hdfs dfsadmin -report" I got something like this (simplified):

Configured Capacity: 3 TB
Present Capacity: 400GB
DFS Remaining: 300 GB
DFS Used: 100 GB

I am wondering what "configured capacity" is and what "present capacity" is. It looks like "Present Capacity" is the one in effect. How can I increase this?

回答1:

Configured Capacity is the total available capacity of the disks/voulmes used for data directory.

Eg: I've three 1TB disks mounted on /Hadoop/sdb1, /Hadoop/sdc1, /Hadoop/sdd1 and I configured HDFS data directory on these volumes as /Hadoop/sdb1/dfs/dn, /Hadoop/sdc1/dfs/dn, /Hadoop/sdd1/dfs/dn, I also keep other non HDFS data in other directories in the same volume in /Hadoop/sdb1/nonhadoop, /Hadoop/sdc1/nonhadoop, /Hadoop/sdd1/nonhadoop, Size of data in the non hadoop directories is (800+900+900)GB.

Remaining space for HDFS will be (200+100+100)GB, Which will be the present capacity, Present capacity may vary depends on the usage of other Non HDFS directories in the same volume/disk, However configured capacity remains same until you add/remove volume/disks from HDFS.

来源：https://stackoverflow.com/questions/31064742/hdfs-capacity-how-to-read-dfsadmin-report