2019独角兽企业重金招聘Python工程师标准>>>

之前的CDH5.8.3安装部署就算是前菜。今天开始写正式的系列第一篇，给自己个完整的笔记整理。

其实目前随便找一本hadoop的书，都会在HDFS的章节把hadoop dfs的命令从查看、推拉、增删、复制剪切等逐一罗列。但是，就连今年刚出版的第n版，已经将hadoop介绍到hadoop2.6以上的，也没有使用hadoop最新官方推荐的hdfs命令交互方式，如果你按照那些命令敲，一大堆的Deprecated。今天这篇博客，我按照类别，将原先的老命令（已经deprecated了）和对应的新命令放到一起做个整理。

（本文出自：https://my.oschina.net/happyBKs/blog/811739）

为了方便以后查阅和给读者一个看了就知道如何用的帮助。我将所有的命令用命令示例的方式给出，不在只是给出其他博客抄来抄去的命令文字说明。不过需要啰嗦的地方也会啰嗦几句。

为了方便说明，先新建hdfs目录，命令我们先用老命令，后面会把新命令罗列。我们建两个目录。

[root@localhost hadoop]#  hadoop fs -mkdir /myhome
[root@localhost hadoop]#  hadoop fs -mkdir /myhome/happyBKs

1. 文件的推与拉：

推：把本地系统文件推到hdfs上。

拉：把hdfs上的文件拉倒本地文件系统目录。

（1）“推”命令：

hadoop dfs -put <本地文件> <HDFS路径：可以是一个目录，文件将被推倒这个目录下，或者是一个文件名，文件推上去会被重新命名>

上面这条命令是从hadoop1开始就有的方式，也是各类书介绍的命令。有的也用hadoop fs .....等等。

下面用这种方式先将hadooptext.txt这个文本文件推到hdfs的根目录/下。

[root@localhost log]# ll
total 32
-rw-r--r--. 1 root root 31894 Dec  9 06:45 hadooptext.txt[root@localhost log]# hadoop dfs -put hadooptext.txt /
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.
16/12/09 06:48:29 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost log]# hadoop dfs -ls /
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.16/12/09 06:49:30 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 2 items
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-04 06:46 /myhome
[root@localhost log]# hadoop dfs -lsr /
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.lsr: DEPRECATED: Please use 'ls -R' instead.
16/12/09 06:50:00 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-04 06:46 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-04 06:46 /myhome/happyBKs

值得注意的是，过程中，CDH5.8 hdfs提示命令已经不被推荐。

那么推荐的方式是什么呢？

“推”命令【官方推荐的新方式】：

hdfs dfs <本地文件> <HDFS路径：可以是一个目录，文件将被推倒这个目录下，或者是一个文件名，文件推上去会被重新命名>

我们用这种方式再来将另一个本地文件googledev.txt推送到hdfs的/myhome/happyBKs目录下。

然后再将刚才那个hadooptext.txt推送到/myhome/happyBKs下，并且命名为hadooptext2.txt。

这样，就不会出现Deprecated的提示了。更重要的是，hdfs dfs命令比hadoop dfs的运行速度快得多，前后对比一下还是比较明显的。

[root@localhost log]# nano
[root@localhost log]# ll
total 36
-rw-r--r--. 1 root root  2185 Dec  9 06:57 googledev.txt
-rw-r--r--. 1 root root 31894 Dec  9 06:45 hadooptext.txt
[root@localhost log]# hdfs dfs -put googledev.txt /myhome/happyBKs
16/12/09 06:57:39 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost log]# hdfs dfs -lsr /
lsr: DEPRECATED: Please use 'ls -R' instead.
16/12/09 06:58:14 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-04 06:46 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-09 06:57 /myhome/happyBKs
-rw-r--r--   1 root supergroup       2185 2016-12-09 06:57 /myhome/happyBKs/googledev.txt
[root@localhost log]# hdfs dfs -put hadooptext.txt /myhome/happyBKs/hadooptext2.txt
16/12/09 06:59:21 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost log]# hdfs dfs -lsr /
lsr: DEPRECATED: Please use 'ls -R' instead.
16/12/09 06:59:29 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-04 06:46 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-09 06:59 /myhome/happyBKs
-rw-r--r--   1 root supergroup       2185 2016-12-09 06:57 /myhome/happyBKs/googledev.txt
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:59 /myhome/happyBKs/hadooptext2.txt
[root@localhost log]#

上传本地整个目录到hdfs也是可以的：

[root@localhost mqbag]# ll
total 8
-rw-r--r--. 1 root root 85 Dec 11 05:32 tangshi1.txt
-rw-r--r--. 1 root root 82 Dec 11 05:33 tangshi2.txt
[root@localhost mqbag]# cd ..
[root@localhost log]#
[root@localhost log]#
[root@localhost log]#
[root@localhost log]# hdfs dfs put mqbag/ /myhome/happyBKs
put: Unknown command
Did you mean -put?  This command begins with a dash.
[root@localhost log]# hdfs dfs -put mqbag/ /myhome/happyBKs
16/12/11 05:50:37 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable[root@localhost log]# hdfs dfs -ls -R /
16/12/11 05:51:43 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-04 06:46 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup       2185 2016-12-09 06:57 /myhome/happyBKs/googledev.txt
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:59 /myhome/happyBKs/hadooptext2.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs/mqbag
-rw-r--r--   1 root supergroup         85 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi1.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi2.txt
[root@localhost log]#

还有一种类似于put的“推”命令 dfs -copyFromLocal

用法完全一样：

[root@localhost mqbag]# hadoop dfs -copyFromLocal *.txt /myhome
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.16/12/11 05:56:29 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable[root@localhost mqbag]# hdfs dfs -ls /myhome
16/12/11 05:57:22 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 3 items
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup         85 2016-12-11 05:56 /myhome/tangshi1.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:56 /myhome/tangshi2.txt

推荐命令：

[root@localhost mqbag]# hdfs dfs -copyFromLocal tangshi1.txt /myhome/tangshi1_1.txt
16/12/11 06:14:43 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost mqbag]# hdfs dfs -ls /myhome
16/12/11 06:14:53 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 4 items
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup         85 2016-12-11 05:56 /myhome/tangshi1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 06:14 /myhome/tangshi1_1.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:56 /myhome/tangshi2.txt
[root@localhost mqbag]#

（3）拉命令

老命令：

[root@localhost mqbag]# hadoop dfs -get /myhome/tangshi1_1.txt ./
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.16/12/11 06:42:39 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost mqbag]# ll
total 12
-rw-r--r--. 1 root root 85 Dec 11 06:42 tangshi1_1.txt
-rw-r--r--. 1 root root 85 Dec 11 05:32 tangshi1.txt
-rw-r--r--. 1 root root 82 Dec 11 05:33 tangshi2.txt

推荐命令：

[root@localhost mqbag]# rm tangshi1_1.txt
rm: remove regular file ‘tangshi1_1.txt’? y[root@localhost mqbag]# hdfs dfs -get /myhome/tangshi1_1.txt tangshi1_1_local.txt
16/12/11 07:03:37 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost mqbag]# ll
total 12
-rw-r--r--. 1 root root 85 Dec 11 07:03 tangshi1_1_local.txt
-rw-r--r--. 1 root root 85 Dec 11 05:32 tangshi1.txt
-rw-r--r--. 1 root root 82 Dec 11 05:33 tangshi2.txt
[root@localhost mqbag]#

拉文件时，还能选择是否拉取crc校验失败的文件，用-ignoreCrc

还能用选项-crc 复制文件以及CRC信息。

hdfs dfs -get [-ignoreCrc] [-crc] <src> <localdst>

（4）把本地文件移动到hdfs，本地不留。

[root@localhost mqbag]# hdfs dfs -moveFromLocal tangshi1_1_local.txt /myhome
16/12/11 07:07:13 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost mqbag]# ll
total 8
-rw-r--r--. 1 root root 85 Dec 11 05:32 tangshi1.txt
-rw-r--r--. 1 root root 82 Dec 11 05:33 tangshi2.txt
[root@localhost mqbag]# hdfs dfs -ls /myhome
16/12/11 07:07:37 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 5 items
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup         85 2016-12-11 05:56 /myhome/tangshi1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 06:14 /myhome/tangshi1_1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 07:07 /myhome/tangshi1_1_local.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:56 /myhome/tangshi2.txt
[root@localhost mqbag]#

2. 文件查看类命令：

（1）查看hdfs某目录：

[root@localhost hadoop]# hdfs dfs -ls /
16/12/13 06:55:28 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 2 items
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 07:07 /myhome

[root@localhost hadoop]# hadoop dfs -lsr /
DEPRECATED: Use of this script to execute hdfs command is deprecated.
Instead use the hdfs command for it.lsr: DEPRECATED: Please use 'ls -R' instead.
16/12/13 07:00:49 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 07:07 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup       2185 2016-12-09 06:57 /myhome/happyBKs/googledev.txt
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:59 /myhome/happyBKs/hadooptext2.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs/mqbag
-rw-r--r--   1 root supergroup         85 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi1.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi2.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 05:56 /myhome/tangshi1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 06:14 /myhome/tangshi1_1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 07:07 /myhome/tangshi1_1_local.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:56 /myhome/tangshi2.txt
[root@localhost hadoop]#
[root@localhost hadoop]# hdfs dfs -ls -R /
16/12/13 07:01:08 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 07:07 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup       2185 2016-12-09 06:57 /myhome/happyBKs/googledev.txt
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:59 /myhome/happyBKs/hadooptext2.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs/mqbag
-rw-r--r--   1 root supergroup         85 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi1.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi2.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 05:56 /myhome/tangshi1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 06:14 /myhome/tangshi1_1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 07:07 /myhome/tangshi1_1_local.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:56 /myhome/tangshi2.txt
[root@localhost hadoop]#

（2）查看HDFS文件、目录的大小和数量的命令

一共四个命令需要知道：三个看大小的和一个看数量的

a. 某个目录的总容量、使用量、剩余量、使用率百分比。（看资源容量时最推荐）

hdfs dfs -df <path>

查看目录的使用情况，如hdfs上该目录的总容量、该目录已经使用了多少字节，还有多少字节可用，使用率的百分比。但不会显示该目录下每个文件或子目录的有哪些及它们的大小信息。

[root@localhost hadoop]# hdfs dfs -df /
16/12/13 07:10:30 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Filesystem                 Size    Used    Available  Use%
hdfs://master:9000  19001245696  143360  12976656384    0%
[root@localhost hadoop]#
[root@localhost hadoop]# hdfs dfs -df /myhome/happyBKs
16/12/15 06:44:46 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Filesystem                 Size    Used    Available  Use%
hdfs://master:9000  19001245696  143360  12976279552    0%
[root@localhost hadoop]#

b. 查看某个目录下的文件和子目录的大小（看子女）和查看某个目录本身的大小（只看本人）

hdfs dfs -du /

显示某目录下的文件和子目录，但是不递归下去显示孙级目录的内容，也不会显示本级目录的总大小。显示这些文件的大小（Byte）

hdfs dfs -du -s /

显示本级目录的总大小，但是不会显示该目录下的任何文件和子目录大小。

下面的是上面两个命令的示例，可以看出区别：

[root@localhost hadoop]# hdfs dfs -du /
16/12/13 07:12:38 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
31894  31894  /hadooptext.txt
34583  34583  /myhome
[root@localhost hadoop]#
[root@localhost hadoop]# hdfs dfs -du /myhome/happyBKs
16/12/15 06:30:53 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
2185   2185   /myhome/happyBKs/googledev.txt
31894  31894  /myhome/happyBKs/hadooptext2.txt
167    167    /myhome/happyBKs/mqbag
[root@localhost hadoop]#

如果我只关心整个目录的总大小：

[root@localhost hadoop]# hdfs dfs -du -s /
16/12/15 06:27:40 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
66477  66477  /
[root@localhost hadoop]# hdfs dfs -du -s /myhome
16/12/15 06:28:11 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
34583  34583  /myhome
[root@localhost hadoop]# hdfs dfs -du -s /myhome/happyBKs
16/12/15 06:28:31 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
34246  34246  /myhome/happyBKs
[root@localhost hadoop]#

当然-du -s还可以写成-dus，不过已经被DEPRECATED了。

[root@localhost hadoop]# hdfs dfs -dus /
dus: DEPRECATED: Please use 'du -s' instead.
16/12/13 07:13:25 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
66477  66477  /

d. 看数量

显示<path>下的目录数和文件数，输出格式：

目录数

文件数

大小

文件名

hdfs dfs -count [-q] /

如果加上-q，可以查看文件索引的情况。

[root@localhost hadoop]# hdfs dfs -count -q /
16/12/13 07:15:29 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
9223372036854775807 9223372036854775794            none             inf            4            9              66477 /
[root@localhost hadoop]#
[root@localhost hadoop]# hdfs dfs -count /
16/12/13 07:16:08 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable4            9              66477 /
[root@localhost hadoop]#

当然，若是要查看hdfs的使用情况和文件，也可以用通过浏览器访问。但请确保hadoop 服务器的对应的hdfs端口已经在防火墙设置过，且最好是永久设置，不然你无法通过50070端口访问。（如果你设置了其他号码为hdfs端口。请设置其他数字）

3. 查看文件的内容

a. 有两个命令都可以用来查看文件的内容：

hdfs dfs -cat <src>

浏览HDFS路径为<src>的文件的内容

-cat [-ignoreCrc] <src> ... :
Fetch all files that match the file pattern <src> and display their content on
stdout.

hdfs dfs -text <src>

强HDFS路径为<src>的文本文件输出

-text [-ignoreCrc] <src> ... :
Takes a source file and outputs the file in text format.
The allowed formats are zip and TextRecordInputStream and Avro.

是不是没看出什么区别？是的，在输出查看文本内容时确实如此：

[root@localhost hadoop]# hdfs dfs -cat /myhome/tangshi1.txt
16/12/18 05:53:03 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
八阵图功盖三分国，名成八阵图。
江流石不转，遗恨失吞吴。
[root@localhost hadoop]# hdfs dfs -text /myhome/tangshi1.txt
16/12/18 05:53:24 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
八阵图功盖三分国，名成八阵图。
江流石不转，遗恨失吞吴。
[root@localhost hadoop]#

b. 查看文件的最后1KB内容、动态监控日志更新

hdfs dfs -tail <src>

查看文件的最后1KB内容。这对查看那种庞大的日志文件来说是十分有用的。

[root@localhost logs]# hdfs dfs -tail /myhome/hadoop-hadoop-datanode-localhost.localdomain.log
16/12/18 06:34:19 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
127.0.0.1:38881, dest: /127.0.0.1:50010, bytes: 15181, op: HDFS_WRITE, cliID: DFSClient_NONMAPREDUCE_586277825_1, offset: 0, srvID: 54611752-a966-4db1-aabe-8d4525b73d78, blockid: BP-1682033911-127.0.0.1-1480341812291:blk_1073741834_1010, duration: 848268122
2016-12-18 06:07:49,911 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: PacketResponder: BP-1682033911-127.0.0.1-1480341812291:blk_1073741834_1010, type=LAST_IN_PIPELINE, downstreams=0:[] terminating
2016-12-18 06:10:41,876 INFO org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetAsyncDiskService: Scheduling blk_1073741834_1010 file /opt/hdfs/data/current/BP-1682033911-127.0.0.1-1480341812291/current/finalized/subdir0/subdir0/blk_1073741834 for deletion
2016-12-18 06:10:41,914 INFO org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetAsyncDiskService: Deleted BP-1682033911-127.0.0.1-1480341812291 blk_1073741834_1010 file /opt/hdfs/data/current/BP-1682033911-127.0.0.1-1480341812291/current/finalized/subdir0/subdir0/blk_1073741834
[root@localhost logs]#

或者说它就是为日志文件量身定制的。因为它还能适用于文件不断变化的情景。

[root@localhost logs]# hdfs dfs -tail -f /myhome/hadoop-hadoop-datanode-localhost.localdomain.log
16/12/18 06:53:31 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
127.0.0.1:38881, dest: /127.0.0.1:50010, bytes: 15181, op: HDFS_WRITE, cliID: DFSClient_NONMAPREDUCE_586277825_1, offset: 0, srvID: 54611752-a966-4db1-aabe-8d4525b73d78, blockid: BP-1682033911-127.0.0.1-1480341812291:blk_1073741834_1010, duration: 848268122
2016-12-18 06:07:49,911 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: PacketResponder: BP-1682033911-127.0.0.1-1480341812291:blk_1073741834_1010, type=LAST_IN_PIPELINE, downstreams=0:[] terminating
2016-12-18 06:10:41,876 INFO org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetAsyncDiskService: Scheduling blk_1073741834_1010 file /opt/hdfs/data/current/BP-1682033911-127.0.0.1-1480341812291/current/finalized/subdir0/subdir0/blk_1073741834 for deletion
2016-12-18 06:10:41,914 INFO org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetAsyncDiskService: Deleted BP-1682033911-127.0.0.1-1480341812291 blk_1073741834_1010 file /opt/hdfs/data/current/BP-1682033911-127.0.0.1-1480341812291/current/finalized/subdir0/subdir0/blk_1073741834
^Ctail: Filesystem closed

加入-f参数会进入一种监控方式，控制台显示了最后1KB内容之后，命令行不会返回，而知等待新内容的到来。输出的内容会随着文件追加内容而更新。非常适用于监控日志文件。停止监控，只需要Ctrl+C

c. 查HDFS上的文件或目录的统计信息

输入下面的命令，查HDFS上的路径为<path>的文件或目录的统计信息。格式为：

%b	文件大小
%n	文件名
%r	复制因子，或者说副本数
%y,%Y	修改日期

看例子吧。

[root@localhost logs]# hadoop fs -stat '%b %n %r %y %Y %o' /myhome/tangshi1.txt
16/12/18 07:22:43 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
85 tangshi1.txt 1 2016-12-11 13:56:32 1481464592248 134217728
[root@localhost logs]# hadoop fs -stat '%b %n %r %y %Y %o' /myhome/
16/12/18 07:24:41 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
0 myhome 0 2016-12-18 14:26:04 1482071164232 0
[root@localhost logs]#

4. HDFS目录的新建、删、移、复制

(1)HDFS目录的新建：

注意：新建目录如果新建的的目录包含多级目录，必须加上-p，否则会由于不认识第一级目录而报错。这个l与linux命令一样啦。

[root@localhost logs]# hdfs dfs -mkdir /yourhome/home1
16/12/18 07:27:49 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
mkdir: '/yourhome/home1': No such file or directory
[root@localhost logs]#
[root@localhost logs]# hdfs dfs -mkdir -p /yourhome/home1
16/12/18 07:28:22 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost logs]# hdfs dfs -ls /
16/12/18 07:28:32 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 3 items
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-18 06:26 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-18 07:28 /yourhome
[root@localhost logs]# hdfs dfs -ls /yourhome
16/12/18 07:28:40 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 1 items
drwxr-xr-x   - root supergroup          0 2016-12-18 07:28 /yourhome/home1
[root@localhost logs]#

(2)HDFS目录的改名和剪切移位：

如果mv的目标目录不存在，那么源目录会被改名；如果目标目录存在，那么源目录会被剪切移位到目标目录下。

[root@localhost sbin]# hdfs dfs mkdir -p /yourhome/home2
mkdir: Unknown command
Did you mean -mkdir?  This command begins with a dash.
[root@localhost sbin]# hdfs dfs -mkdir -p /yourhome/home2
16/12/22 07:03:07 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost sbin]#
[root@localhost sbin]#
[root@localhost sbin]# hdfs dfs -ls /yourhome
16/12/22 07:03:18 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 2 items
drwxr-xr-x   - root supergroup          0 2016-12-18 07:28 /yourhome/home1
drwxr-xr-x   - root supergroup          0 2016-12-22 07:03 /yourhome/home2
[root@localhost sbin]# hdfs dfs -mv /yourhome/home1 /yourhome/home3
16/12/22 07:04:57 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost sbin]# hdfs dfs -ls /yourhome
16/12/22 07:05:03 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 2 items
drwxr-xr-x   - root supergroup          0 2016-12-22 07:03 /yourhome/home2
drwxr-xr-x   - root supergroup          0 2016-12-18 07:28 /yourhome/home3[root@localhost sbin]# hdfs dfs -ls -R /yourhome
16/12/22 07:05:28 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
drwxr-xr-x   - root supergroup          0 2016-12-22 07:03 /yourhome/home2
drwxr-xr-x   - root supergroup          0 2016-12-18 07:28 /yourhome/home3
[root@localhost sbin]#
[root@localhost sbin]# hdfs dfs -mv /yourhome/home2 /yourhome/home3
16/12/22 07:05:47 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost sbin]# hdfs dfs -ls -R /yourhome
16/12/22 07:05:53 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
drwxr-xr-x   - root supergroup          0 2016-12-22 07:05 /yourhome/home3
drwxr-xr-x   - root supergroup          0 2016-12-22 07:03 /yourhome/home3/home2
[root@localhost sbin]#

(3)HDFS目录的删除

删除目录的时候，不要忘记-r

[root@localhost sbin]# hdfs dfs -rm -r /yourhome/home3
16/12/22 07:14:36 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Deleted /yourhome/home3

删除的时候注意，hdfs上的删除默认都是标记为删除，实际上在hdfs的回收站里依然占据着空间。要想彻底删除，必须把回收站清空，命令如下：

[root@localhost sbin]# hdfs dfs -expunge
16/12/22 07:17:48 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost sbin]#

或者在rm时加入-skipTrash，这样就能直接删除干净了。有点像windows下你按住shift+DEL。

[root@localhost sbin]# hdfs dfs -rm -r -skipTrash /yourhome/home3
16/12/22 07:19:03 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Deleted /yourhome/home3
[root@localhost sbin]#

假如你是那种把绝密文件放在自己虚拟机hdfs上的男同胞，冠希哥的错误不要在学习hdfs的路程中再犯了。

(4)HDFS目录的复制：

复制目录的时候，用的不是-r，而是-f。

[root@localhost hadoop]# hdfs dfs -cp -f /yourhome /yourhome2
16/12/24 07:06:41 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost hadoop]# hdfs dfs -ls /your*
16/12/24 07:06:59 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 1 items
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /yourhome/hadooparticle.txt
Found 1 items
-rw-r--r--   1 root supergroup      31894 2016-12-24 07:06 /yourhome2/hadooparticle.txt
[root@localhost hadoop]# hdfs dfs -rm -r -skipTrash /yourhome
16/12/24 07:09:07 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Deleted /yourhome
[root@localhost hadoop]#

5. 文件的增删移位

(1)在HDFS上新建一个空文件：

[root@localhost hadoop]# hdfs dfs -touchz /blacnk.txt
16/12/24 06:33:03 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost hadoop]# hdfs dfs -ls /
16/12/24 06:33:11 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 4 items
-rw-r--r--   1 root supergroup          0 2016-12-24 06:33 /blacnk.txt
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-18 06:26 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-22 07:19 /yourhome[root@localhost hadoop]# hdfs dfs -cat /blacnk.txt
16/12/24 06:33:49 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost hadoop]#

(2)删除HDFS上的一个文件

[root@localhost hadoop]# hdfs dfs -rm -skipTrash /blacnk.txt
16/12/24 06:40:15 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Deleted /blacnk.txt
[root@localhost hadoop]#

(3)将HDFS上的文件剪切移位：

[root@localhost hadoop]# hdfs dfs -ls -R /
16/12/24 06:28:22 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-18 06:26 /myhome
-rw-r--r--   1 root supergroup     171919 2016-12-18 06:26 /myhome/hadoop-hadoop-datanode-localhost.localdomain.log
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup       2185 2016-12-09 06:57 /myhome/happyBKs/googledev.txt
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:59 /myhome/happyBKs/hadooptext2.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs/mqbag
-rw-r--r--   1 root supergroup         85 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi1.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi2.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 05:56 /myhome/tangshi1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 06:14 /myhome/tangshi1_1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 07:07 /myhome/tangshi1_1_local.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:56 /myhome/tangshi2.txt
drwxr-xr-x   - root supergroup          0 2016-12-22 07:19 /yourhome[root@localhost hadoop]# hdfs dfs -mv /hadooptext.txt /yourhome
16/12/24 06:44:04 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost hadoop]# hdfs dfs -ls -R /
16/12/24 06:44:19 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
drwxr-xr-x   - root supergroup          0 2016-12-18 06:26 /myhome
-rw-r--r--   1 root supergroup     171919 2016-12-18 06:26 /myhome/hadoop-hadoop-datanode-localhost.localdomain.log
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs
-rw-r--r--   1 root supergroup       2185 2016-12-09 06:57 /myhome/happyBKs/googledev.txt
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:59 /myhome/happyBKs/hadooptext2.txt
drwxr-xr-x   - root supergroup          0 2016-12-11 05:50 /myhome/happyBKs/mqbag
-rw-r--r--   1 root supergroup         85 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi1.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:50 /myhome/happyBKs/mqbag/tangshi2.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 05:56 /myhome/tangshi1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 06:14 /myhome/tangshi1_1.txt
-rw-r--r--   1 root supergroup         85 2016-12-11 07:07 /myhome/tangshi1_1_local.txt
-rw-r--r--   1 root supergroup         82 2016-12-11 05:56 /myhome/tangshi2.txt
drwxr-xr-x   - root supergroup          0 2016-12-24 06:44 /yourhome
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /yourhome/hadooptext.txt
[root@localhost hadoop]#

(4)hdfs文件重命名

前面用mv可以移动hdfs目录，也可以为目录重命名。mv对hdfs文件也是一样。

[root@localhost hadoop]# hdfs dfs -mv /yourhome/hadooptext.txt /yourhome/hadooparticle.txt
16/12/24 06:58:11 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost hadoop]# hdfs dfs -ls /yourhome
16/12/24 06:58:25 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 1 items
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /yourhome/hadooparticle.txt
[root@localhost hadoop]#

(5)hdfs复制文件

复制的时候可以只指定文件复制的目标目录位置；也可以指定一个完整的目标文件名，即在复制的同时为文件改名字。

[root@localhost hadoop]# hdfs dfs -cp /yourhome/hadooparticle.txt /
16/12/24 07:00:04 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost hadoop]#
[root@localhost hadoop]# hdfs dfs -ls / /yourhome
16/12/24 07:00:30 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 3 items
-rw-r--r--   1 root supergroup      31894 2016-12-24 07:00 /hadooparticle.txt
drwxr-xr-x   - root supergroup          0 2016-12-18 06:26 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-24 06:58 /yourhome
Found 1 items
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /yourhome/hadooparticle.txt
[root@localhost hadoop]#
[root@localhost hadoop]# hdfs dfs -cp /hadooparticle.txt /hadooptext.txt
16/12/24 07:01:17 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[root@localhost hadoop]# hdfs dfs -ls / /yourhome
16/12/24 07:01:22 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 4 items
-rw-r--r--   1 root supergroup      31894 2016-12-24 07:00 /hadooparticle.txt
-rw-r--r--   1 root supergroup      31894 2016-12-24 07:01 /hadooptext.txt
drwxr-xr-x   - root supergroup          0 2016-12-18 06:26 /myhome
drwxr-xr-x   - root supergroup          0 2016-12-24 06:58 /yourhome
Found 1 items
-rw-r--r--   1 root supergroup      31894 2016-12-09 06:49 /yourhome/hadooparticle.txt
[root@localhost hadoop]#

这里其实提到了ls的一个用法，显示多个目录下的内容，只要在-ls后面逐个列举就可以了，显示的时候会分开显示，并显示每个列举的目录下有多少个文件或者子目录，Found x items。

至于编辑HDFS上的文件内容，那你就别想了。老老实实把要修改的文件get下来，再put回去吧。

6. 一个非常有用的文件条件判断命令

test
使用方法：hadoop fs -test -[ezd] URI

选项：
-e 检查文件是否存在。如果存在则返回0。
-z 检查文件是否是0字节。如果是则返回0。
-d 如果路径是个目录，则返回1，否则返回0。

不过这玩意是不显示的，所以别傻敲。

最后，我把hdfs命令在三种命令形式的区别给出：比较权威的区别解释：不翻译了。

Following are the three commands which appears same but have minute differences

hadoop fs {args}
hadoop dfs {args}
hdfs dfs {args}
```
hadoop fs <args>
```

FS relates to a generic file system which can point to any file systems like local, HDFS etc. So this can be used when you are dealing with different file systems such as Local FS, HFTP FS, S3 FS, and others

  hadoop dfs <args>

dfs is very specific to HDFS. would work for operation relates to HDFS. This has been deprecated and we should use hdfs dfs instead.

  hdfs   dfs <args>

same as 2nd i.e would work for all the operations related to HDFS and is the recommended command instead of hadoop dfs

below is the list categorized as HDFS commands.

  **#hdfs commands**namenode|secondarynamenode|datanode|dfs|dfsadmin|fsck|balancer|fetchdt|oiv|dfsgroups

So even if you use Hadoop dfs , it will look locate hdfs and delegate that command to hdfs dfs

最后的最后，介绍hdfs中最有用的命令： --help，不知道的时候，查就是了！

[root@localhost mqbag]# hdfs --help
Usage: hdfs [--config confdir] COMMANDwhere COMMAND is one of:dfs                  run a filesystem command on the file systems supported in Hadoop.namenode -format     format the DFS filesystemsecondarynamenode    run the DFS secondary namenodenamenode             run the DFS namenodejournalnode          run the DFS journalnodezkfc                 run the ZK Failover Controller daemondatanode             run a DFS datanodedfsadmin             run a DFS admin clientdiskbalancer         Distributes data evenly among disks on a given nodehaadmin              run a DFS HA admin clientfsck                 run a DFS filesystem checking utilitybalancer             run a cluster balancing utilityjmxget               get JMX exported values from NameNode or DataNode.mover                run a utility to move block replicas acrossstorage typesoiv                  apply the offline fsimage viewer to an fsimageoiv_legacy           apply the offline fsimage viewer to an legacy fsimageoev                  apply the offline edits viewer to an edits filefetchdt              fetch a delegation token from the NameNodegetconf              get config values from configurationgroups               get the groups which users belong tosnapshotDiff         diff two snapshots of a directory or diff thecurrent directory contents with a snapshotlsSnapshottableDir   list all snapshottable dirs owned by the current userUse -help to see optionsportmap              run a portmap servicenfs3                 run an NFS version 3 gatewaycacheadmin           configure the HDFS cachecrypto               configure HDFS encryption zonesstoragepolicies      list/get/set block storage policiesversion              print the versionMost commands print help when invoked w/o parameters.
[root@localhost mqbag]# hdfs version
Hadoop 2.6.0-cdh5.8.3
Subversion http://github.com/cloudera/hadoop -r 992be3bac6b145248d32c45b16f8fce5a984b158
Compiled by jenkins on 2016-10-13T03:23Z
Compiled with protoc 2.5.0
From source with checksum ef7968b8b98491d54f83cb3bd7a87ea
This command was run using /opt/hadoop-2.6.0-cdh5.8.3/share/hadoop/common/hadoop-common-2.6.0-cdh5.8.3.jar
[root@localhost mqbag]#

转载于:https://my.oschina.net/happyBKs/blog/811739

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Hadoop笔记（1）——hdfs命令访问方式

1. 文件的推与拉：

（1）“推”命令：

（3）拉命令

（4）把本地文件移动到hdfs，本地不留。

2. 文件查看类命令：

（1）查看hdfs某目录：

a. 某个目录的总容量、使用量、剩余量、使用率百分比。（看资源容量时最推荐）

b. 查看某个目录下的文件和子目录的大小（看子女）和查看某个目录本身的大小（只看本人）

d. 看数量

3. 查看文件的内容

a. 有两个命令都可以用来查看文件的内容：

b. 查看文件的最后1KB内容、动态监控日志更新

c. 查HDFS上的文件或目录的统计信息

4. HDFS目录的新建、删、移、复制

(1)HDFS目录的新建：

(2)HDFS目录的改名和剪切移位：

(3)HDFS目录的删除

5. 文件的增删移位

(1)在HDFS上新建一个空文件：

(2)删除HDFS上的一个文件

(3)将HDFS上的文件剪切移位：

(4)hdfs文件重命名

(5)hdfs复制文件

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Hadoop笔记（1）——hdfs命令访问方式

1. 文件的推与拉：

（1）“推”命令：

（3）拉命令

（4） 把本地文件移动到hdfs，本地不留。

2. 文件查看类命令：

（1）查看hdfs某目录：

a. 某个目录的总容量、使用量、剩余量、使用率百分比。（看资源容量时最推荐）

b. 查看某个目录下的文件和子目录的大小（看子女）和查看某个目录本身的大小（只看本人）

d. 看数量

3. 查看文件的内容

a. 有两个命令都可以用来查看文件的内容：

b. 查看文件的最后1KB内容 、动态监控日志更新

c. 查HDFS上的文件或目录的统计信息

4. HDFS目录的新建、删、移、复制

(1)HDFS目录的新建：

(2)HDFS目录的改名和剪切移位：

(3)HDFS目录的删除

5. 文件的增删移位

(1)在HDFS上新建一个空文件：

(2)删除HDFS上的一个文件

(3)将HDFS上的文件剪切移位：

(4)hdfs文件重命名

(5)hdfs复制文件

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（4）把本地文件移动到hdfs，本地不留。

b. 查看文件的最后1KB内容、动态监控日志更新