HDFS的Shell操作
1.基本语法
bin/hadoop fs 具体命令 OR bin/hdfs dfs 具体命令
dfs是fs的实现类。
2.命令大全
[Tesla@hadoop102 hadoop-2.7.2]$ bin/hadoop fs [-appendToFile <localsrc> ... <dst>] [-cat [-ignoreCrc] <src> ...] [-checksum <src> ...] [-chgrp [-R] GROUP PATH...] [-chmod [-R] <MODE[,MODE]... | OCTALMODE> PATH...] [-chown [-R] [OWNER][:[GROUP]] PATH...] [-copyFromLocal [-f] [-p] <localsrc> ... <dst>] [-copyToLocal [-p] [-ignoreCrc] [-crc] <src> ... <localdst>] [-count [-q] <path> ...] [-cp [-f] [-p] <src> ... <dst>] [-createSnapshot <snapshotDir> [<snapshotName>]] [-deleteSnapshot <snapshotDir> <snapshotName>] [-df [-h] [<path> ...]] [-du [-s] [-h] <path> ...] [-expunge] [-get [-p] [-ignoreCrc] [-crc] <src> ... <localdst>] [-getfacl [-R] <path>] [-getmerge [-nl] <src> <localdst>] [-help [cmd ...]] [-ls [-d] [-h] [-R] [<path> ...]] [-mkdir [-p] <path> ...] [-moveFromLocal <localsrc> ... <dst>] [-moveToLocal <src> <localdst>] [-mv <src> ... <dst>] [-put [-f] [-p] <localsrc> ... <dst>] [-renameSnapshot <snapshotDir> <oldName> <newName>] [-rm [-f] [-r|-R] [-skipTrash] <src> ...] [-rmdir [--ignore-fail-on-non-empty] <dir> ...] [-setfacl [-R] [{-b|-k} {-m|-x <acl_spec>} <path>]|[--set <acl_spec> <path>]] [-setrep [-R] [-w] <rep> <path> ...] [-stat [format] <path> ...] [-tail [-f] <file>] [-test -[defsz] <path>] [-text [-ignoreCrc] <src> ...] [-touchz <path> ...] [-usage [cmd ...]]
3.常用命令实操
(0)启动Hadoop集群(方便后续的测试)
[Tesla@hadoop102 hadoop-2.7.2]$ sbin/start-dfs.sh [Tesla@hadoop103 hadoop-2.7.2]$ sbin/start-yarn.sh
(1)-help:输出这个命令参数
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -help rm
(2)-ls: 显示目录信息
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -ls /
(3)-mkdir:在HDFS上创建目录
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -mkdir -p /sanguo/shuguo
(4)-moveFromLocal:从本地剪切粘贴到HDFS
[Tesla@hadoop102 hadoop-2.7.2]$ touch kongming.txt [Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -moveFromLocal ./kongming.txt /sanguo/shuguo
(5)-appendToFile:追加一个文件到已经存在的文件末尾
[Tesla@hadoop102 hadoop-2.7.2]$ touch liubei.txt [Tesla@hadoop102 hadoop-2.7.2]$ vi liubei.txt 输入 san gu mao lu [Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -appendToFile liubei.txt /sanguo/shuguo/kongming.txt
(6)-cat:显示文件内容
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -cat /sanguo/shuguo/kongming.txt
(7)-chgrp 、-chmod、-chown:Linux文件系统中的用法一样,修改文件所属权限
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -chmod 666 /sanguo/shuguo/kongming.txt [Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -chown Tesla:Tesla /sanguo/shuguo/kongming.txt
(8)-copyFromLocal:从本地文件系统中拷贝文件到HDFS路径去
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -copyFromLocal README.txt /
(9)-copyToLocal:从HDFS拷贝到本地
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -copyToLocal /sanguo/shuguo/kongming.txt ./
(10)-cp :从HDFS的一个路径拷贝到HDFS的另一个路径
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -cp /sanguo/shuguo/kongming.txt /zhuge.txt
(11)-mv:在HDFS目录中移动文件
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -mv /zhuge.txt /sanguo/shuguo/
(12)-get:等同于copyToLocal,就是从HDFS下载文件到本地
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -get /sanguo/shuguo/kongming.txt ./
(13)-getmerge:合并下载多个文件,比如HDFS的目录 /user/Tesla/test下有多个文件:log.1, log.2,log.3,...
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -getmerge /user/Tesla/test/* ./zaiyiqi.txt
(14)-put:等同于copyFromLocal
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -put ./zaiyiqi.txt /user/Tesla/test/
(15)-tail:显示一个文件的末尾
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -tail /sanguo/shuguo/kongming.txt
(16)-rm:删除文件或文件夹
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -rm /user/Tesla/test/jinlian2.txt
(17)-rmdir:删除空目录
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -mkdir /test [Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -rmdir /test
(18)-du统计文件夹的大小信息
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -du -s -h /user/Tesla/test 2.7 K /user/Tesla/test [Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -du -h /user/Tesla/test 1.3 K /user/Tesla/test/README.txt 15 /user/Tesla/test/jinlian.txt 1.4 K /user/Tesla/test/zaiyiqi.txt
(19)-setrep:设置HDFS中文件的副本数量
[Tesla@hadoop102 hadoop-2.7.2]$ hadoop fs -setrep 10 /sanguo/shuguo/kongming.txt
这里设置的副本数只是记录在NameNode的元数据中,是否真的会有这么多副本,还得看DataNode的数量。因为目前只有3台设备,最多也就3个副本,只有节点数的增加到10台时,副本数才能达到10。