what is Non DFS Used in cluster summary ?how to delete it?

[Pravin Karne <pr...@persistent.co.in>]

Hi,
I am using Nutch 1.0 with 10 node cluster.

I have crawled 1000 sites with 10 depth.
I got following cluster summary
5538 files and directories, 4556 blocks = 10094 total. Heap Size is 50 MB / 888.94 MB (5%)
Configured Capacity       :               140 TB
DFS Used             :               146.91 GB
Non DFS Used   :               2.25 TB
DFS Remaining  :               137.61 TB
DFS Used%         :               0.1 %
DFS Remaining%              :               98.29 %



But what is  "Non DFS Used"?.What is location for this data on  HDFS ? How to delete this data ?
I have format name node lot many time but this data not cleared.

Thanks in advanced

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