1. Is supergroup a directory? Where does it locate?
supergroup is user group rather than directory just like the user group
of linux
2. I search abc.txt on master 172.11.12.6 and node1 172.11.12.7 by
following command:
the meadata(file name, file path and block location) is in master, the
file data itself is in datanode.
On Sun, Jan 26, 2014 at 2:22 PM, EdwardKing <zhan...@neusoft.com> wrote:
> I use Hadoop2.2.0 to create a master node and a sub node,like follows:
>
> Live Datanodes : 2
> Node Transferring Address Last Contact Admin State Configured Capacity
> (GB) Used(GB) Non DFS Used (GB) Remaining(GB) Used(%)
> master 172.11.12.6:50010 1 In Service
> 16.15 0.00 2.76
> 13.39 0.00
> node1 172.11.12.7:50010 0 In Service
> 16.15 0.00 2.75
> 13.40 0.00
>
> Then I create a abc.txt file on master 172.11.12.6
> [hadoop@master ~]$ pwd
> /home/hadoop
> [hadoop@master ~]$ echo "This is a test." >> abc.txt
> [hadoop@master ~]$ hadoop dfs -copyFromLocal test.txt
> [hadoop@master ~]$ hadoop dfs -ls
> DEPRECATED: Use of this script to execute hdfs command is deprecated.
> Instead use the hdfs command for it.
>
> 14/01/25 22:07:00 WARN util.NativeCodeLoader: Unable to load native-hadoop
> library for your platform... using builtin-java classes where applicable
> Found 1 items
> -rw-r--r-- 2 hadoop supergroup 16 2014-01-25 21:36 abc.txt
>
> [hadoop@master ~]$ rm abc.txt
> [hadoop@master ~]$ hadoop dfs -cat abc.txt
> This is a test.
>
> My question is:
> 1. Is supergroup a directory? Where does it locate?
> 2. I search abc.txt on master 172.11.12.6 and node1 172.11.12.7 by
> following command:
> [hadoop@master ~]$ find / -name abc.txt
> But I don't find abc.txt file. Where is the file abc.txt? After I erase it
> by rm command, I still cat this file? Where is it? My OS is CentOS-5.8.
>
> Thanks.
>
> ---------------------------------------------------------------------------------------------------
> Confidentiality Notice: The information contained in this e-mail and any
> accompanying attachment(s)
> is intended only for the use of the intended recipient and may be
> confidential and/or privileged of
> Neusoft Corporation, its subsidiaries and/or its affiliates. If any reader
> of this communication is
> not the intended recipient, unauthorized use, forwarding, printing,
> storing, disclosure or copying
> is strictly prohibited, and may be unlawful.If you have received this
> communication in error,please
> immediately notify the sender by return e-mail, and delete the original
> message and all copies from
> your system. Thank you.
>
> ---------------------------------------------------------------------------------------------------
>
