Useful commands for Hadoop HDFS troubleshooting

[hadoop@master ~]$ hdfs dfsadmin -report
17/04/13 00:06:51 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform… using builtin-java classes where applicable
Configured Capacity: 37576769536 (35.00 GB)
Present Capacity: 33829806080 (31.51 GB)
DFS Remaining: 33829789696 (31.51 GB)
DFS Used: 16384 (16 KB)
DFS Used%: 0.00%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0
Missing blocks (with replication factor 1): 0

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Live datanodes (2):

Name: 192.168.1.82:50010 (lab2.rmohan.com)
Hostname: lab2.rmohan.com
Decommission Status : Normal
Configured Capacity: 18788384768 (17.50 GB)
DFS Used: 8192 (8 KB)
Non DFS Used: 1873375232 (1.74 GB)
DFS Remaining: 16915001344 (15.75 GB)
DFS Used%: 0.00%
DFS Remaining%: 90.03%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Apr 13 00:06:49 SGT 2017
Name: 192.168.1.81:50010 (lab1.rmohan.com)
Hostname: lab1.rmohan.com
Decommission Status : Normal
Configured Capacity: 18788384768 (17.50 GB)
DFS Used: 8192 (8 KB)
Non DFS Used: 1873588224 (1.74 GB)
DFS Remaining: 16914788352 (15.75 GB)
DFS Used%: 0.00%
DFS Remaining%: 90.03%
Configured Cache Capacity: 0 (0 B)
Cache Used: 0 (0 B)
Cache Remaining: 0 (0 B)
Cache Used%: 100.00%
Cache Remaining%: 0.00%
Xceivers: 1
Last contact: Thu Apr 13 00:06:49 SGT 2017