安全模式：集群启动时，DN所有的DN都必须向MM汇报磁盘使用状态和block存储信息。在此之前出于对hdfs的保护，会禁止访问hdfs，此状态为安全模式
1.查看安全模式状态 #查看安全模式状态hdfs dfsadmin --safemode get#-状态-on|off#----- 2.手工开启安全模式状态 #手工进入安全模式hdfs dfsadmin --safemode enter 3.手工关闭安全模式状态 #手工退出安全模式hdfs dfsadmin --safemode leave 2、文件操作指令指令的一般格式如下：
hdfs dfs -CMD [-OPTION] [path1] ★★★#使用较多hadoop fs -CMD [-OPTION] [path1] 1.查看文件目录 #查看指定路径的当前目录结构hdfs dfs -ls #查看HDFS根目录结构的文件组成hdfs dfs -ls /#--------------------------------------------------------------Found 1 itemsdrwxrwx--- - root supergroup 0 2023-12-29 08:37 /tmp#--------------------------------------------------------------#递归查看指定路径的目录结构hdfs dfs -ls -R #递归根目录的目录结构hdfs dfs -lsr /hdfs dfs -ls -R /#----------------------------------------------------------------------------------------drwxr-xr-x - root supergroup 0 2023-12-29 10:07 /testdrwxr-xr-x - root supergroup 0 2023-12-29 10:07 /test/kb16drwxr-xr-x - root supergroup 0 2023-12-29 12:25 /test/kb16/hadoop-rw-r--r-- 1 root supergroup 678260987 2023-12-29 12:25 /test/kb16/hadoop/ratings.csv#---------------------------------------------------------------------------------------- 2.查看文件夹情况 #统计目录下个文件大小hdfs dfs -du #统计/test/kb16/hadoop/下文件大小hdfs dfs -du /test/hadoop/#--------------------------------------------------678260987 678260987 /test/hadoop/test1.csv#--------------------------------------------------#汇总统计目录下文件(夹)大小hdfs dfs -du -s #汇总统计目录下文件(夹)大小hdfs dfs -du -s /#----------------------678260987 678260987 /#----------------------#统计文件(夹)数量hdfs dfs -count [-q] #统计文件(夹)数量#-------------------10 1 678260987 /#------------------- 3.文件操作 #移动文件hdfs dfs -mv #将ratings.csv移动到/tmp/hadoop-yarn中hdfs dfs -mv /test/hadoop/ratings.csv /tmp/hadoop-yarn#--------------------------------------------------------------------------------------drwxr-xr-x - root supergroup 0 2023-12-29 10:07 /testdrwxr-xr-x - root supergroup 0 2023-12-29 10:07 /test/kb16drwxr-xr-x - root supergroup 0 2023-12-29 17:41 /test/kb16/hadoopdrwxrwx--- - root supergroup 0 2023-12-29 08:37 /tmpdrwxrwx--- - root supergroup 0 2023-12-29 17:41 /tmp/hadoop-yarn-rw-r--r-- 1 root supergroup 678260987 2023-12-29 12:25 /tmp/hadoop-yarn/ratings.csv#---------------------------------------------------------------------------------------#将指定路径文件复制到目标路径hdfs dfs -cp #将/test/kb16/hadoop下的ratings.csv复制到test/kb16中hdfs dfs -cp hdfs dfs -cp /test/hadoop/ratings.csv /test/kb16#------------------------------------------------------------------------------------2023-12-29 17:47:27,806 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:27,980 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:28,537 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:29,513 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:30,365 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:31,239 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:32,106 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false /test/kb162023-12-29 17:47:27,806 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:27,980 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:28,537 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:29,513 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:30,365 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:31,239 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:32,106 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#------------------------------------------------------------------------------------#删除文件/空白文件夹hdfs dfs -rm [-skiptrash] #删除/test/kb16下的ratings.csvhdfs dfs -rm /test/ratings.csv#-----------------------------Deleted /test/ratings.csv#-----------------------------#递归删除文件/空白文件夹hdfs dfs -rmr [-skiptrash] 4.上传文件 #上传文件到hadoop中hdfs dfs -put #上传文件到/test/kb16中hdfs dfs -put ratings.csv /test/#-------------------------------------------------------------------------------------2023-12-29 18:07:24,565 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:25,012 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:25,257 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:25,673 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:26,478 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:27,162 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#-------------------------------------------------------------------------------------#将本地文件移动到hdfs路径上hdfs dfs -copyfromlocal #将本地文件复制到hdfs路径上hdfs dfs -movefromlocal 5、获取文件 #将hdfs中路径文件下载到本地hdfs dfs -get #将hadoop中/test/kb16/hadoop下的ratings.csv下载到根目录中hdfs dfs -get /test/hadoop/ratings.csv ~/#-------------------------------------------------------------------------------------2023-12-29 18:15:14,441 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#-------------------------------------------------------------------------------------#将hdfs中路径文件合并到本地hdfs dfs -getmerge #hdfs dfs -getmerge /test/hadoop/ratings.csv ratings.csv #-------------------------------------------------------------------------------------2023-12-29 18:18:08,398 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#-------------------------------------------------------------------------------------#将文件从HDFS中复制到本地hdfs dfs -copytolocal [-ignorecrc] [-crc] [hdfs源路径] [linux目的路径] #将文件从HDFS中移动到本地hdfs dfs -movetolocal [-crc] 从本地移动 6.查看文件内容 #利用管道符进行文件的查看hdfs dfs -cat path|查询范围#利用text命令查看文件内容hdfs dfs -text 查看文件内容#查看文件尾部信息hdfs dfs -tail [-f] #查看文件头部信息hdfs dfs -head [-f] 7.创建目录 #创建多级文件目录hdfs dfs -mkdir -p path1/path2 8.修改副本数量修改hadoop备份的副本数量，默认是三份
#修改hadoop备份的副本数量hdfs dfs -setrep [-r] [-w] 9.创建空白文件（不推荐使用）利用-touchz命令创建空白文件的过程中可能会产生错误，因此不推荐使用这个命令
#在指定路径上创建创建空白文件hdfs dfs -touchz 10.显示文件统计信息 #显示文件统计信息hdfs dfs -stat -stat [format] #------------------2023-12-29 04:25:27#------------------ 11、修改权限 #修改文件权限hdfs dfs -chmod [-r] [路径]#修改文件的所有者hdfs dfs -chown [-r] [属主][:[属组]] 路径 #修改文件所属的用户组hdfs dfs -chgrp [-r] 属组名称 路径 12、查看指令的帮助信息 #查看指令的帮助信息hdfs dfs -help [命令选项] 1、安全模式安全模式：集群启动时，DN所有的DN都必须向MM汇报磁盘使用状态和block存储信息。在此之前出于对hdfs的保护，会禁止访问hdfs，此状态为安全模式
1.查看安全模式状态 #查看安全模式状态hdfs dfsasmin --safemode get#-状态-on|off#----- 2.手工开启安全模式状态 #手工进入安全模式hdfs dfsasmin --safemode enter 3.手工关闭安全模式状态 #手工退出安全模式hdfs dfsasmin --safemode leave 2、文件操作指令指令的一般格式如下：
hdfs dfs -CMD [-OPTION] [path1] ★★★#使用较多hadoop fs -CMD [-OPTION] [path1] 1.查看文件目录 #查看指定路径的当前目录结构hdfs dfs -ls #查看HDFS根目录结构的文件组成hdfs dfs -ls /#--------------------------------------------------------------Found 1 itemsdrwxrwx--- - root supergroup 0 2023-12-29 08:37 /tmp#--------------------------------------------------------------#递归查看指定路径的目录结构hdfs dfs -ls -R #递归根目录的目录结构hdfs dfs -lsr /hdfs dfs -ls -R /#----------------------------------------------------------------------------------------drwxr-xr-x - root supergroup 0 2023-12-29 10:07 /testdrwxr-xr-x - root supergroup 0 2023-12-29 10:07 /test/kb16drwxr-xr-x - root supergroup 0 2023-12-29 12:25 /test/kb16/hadoop-rw-r--r-- 1 root supergroup 678260987 2023-12-29 12:25 /test/kb16/hadoop/ratings.csv#---------------------------------------------------------------------------------------- 2.查看文件夹情况 #统计目录下个文件大小hdfs dfs -du #统计/test/kb16/hadoop/下文件大小hdfs dfs -du /test/kb16/hadoop/#--------------------------------------------------678260987 678260987 /test/kb16/hadoop/ratings.csv#--------------------------------------------------#汇总统计目录下文件(夹)大小hdfs dfs -du -s #汇总统计目录下文件(夹)大小hdfs dfs -du -s /#----------------------678260987 678260987 /#----------------------#统计文件(夹)数量hdfs dfs -count [-q] #统计文件(夹)数量#-------------------10 1 678260987 /#------------------- 3.文件操作 #移动文件hdfs dfs -mv #将ratings.csv移动到/tmp/hadoop-yarn中hdfs dfs -mv /test/kb16/hadoop/ratings.csv /tmp/hadoop-yarn#--------------------------------------------------------------------------------------drwxr-xr-x - root supergroup 0 2023-12-29 10:07 /testdrwxr-xr-x - root supergroup 0 2023-12-29 10:07 /test/kb16drwxr-xr-x - root supergroup 0 2023-12-29 17:41 /test/kb16/hadoopdrwxrwx--- - root supergroup 0 2023-12-29 08:37 /tmpdrwxrwx--- - root supergroup 0 2023-12-29 17:41 /tmp/hadoop-yarn-rw-r--r-- 1 root supergroup 678260987 2023-12-29 12:25 /tmp/hadoop-yarn/ratings.csv#---------------------------------------------------------------------------------------#将指定路径文件复制到目标路径hdfs dfs -cp #将/test/kb16/hadoop下的ratings.csv复制到test/kb16中hdfs dfs -cp hdfs dfs -cp /test/kb16/hadoop/ratings.csv /test/kb16#------------------------------------------------------------------------------------2023-12-29 17:47:27,806 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:27,980 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:28,537 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:29,513 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:30,365 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:31,239 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:32,106 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false /test/kb162023-12-29 17:47:27,806 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:27,980 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:28,537 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:29,513 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:30,365 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:31,239 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 17:47:32,106 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#------------------------------------------------------------------------------------#删除文件/空白文件夹hdfs dfs -rm [-skiptrash] #删除/test/kb16下的ratings.csvhdfs dfs -rm /test/kb16/ratings.csv#-----------------------------Deleted /test/kb16/ratings.csv#-----------------------------#递归删除文件/空白文件夹hdfs dfs -rmr [-skiptrash] 4.上传文件 #上传文件到hadoop中hdfs dfs -put #上传文件到/test/kb16中hdfs dfs -put ratings.csv /test/kb16#-------------------------------------------------------------------------------------2023-12-29 18:07:24,565 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:25,012 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:25,257 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:25,673 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:26,478 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false2023-12-29 18:07:27,162 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#-------------------------------------------------------------------------------------#将本地文件移动到hdfs路径上hdfs dfs -copyfromlocal #将本地文件复制到hdfs路径上hdfs dfs -movefromlocal 5、获取文件 #将hdfs中路径文件下载到本地hdfs dfs -get #将hadoop中/test/kb16/hadoop下的ratings.csv下载到根目录中hdfs dfs -get /test/kb16/hadoop/ratings.csv ~/#-------------------------------------------------------------------------------------2023-12-29 18:15:14,441 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#-------------------------------------------------------------------------------------#将hdfs中路径文件合并到本地hdfs dfs -getmerge #hdfs dfs -getmerge /test/kb16/hadoop/ratings.csv ratings.csv #-------------------------------------------------------------------------------------2023-12-29 18:18:08,398 INFO sasl.SaslDataTransferClient: SASL encryption trust check: localHostTrusted = false, remoteHostTrusted = false#-------------------------------------------------------------------------------------#将文件从HDFS中复制到本地hdfs dfs -copytolocal [-ignorecrc] [-crc] [hdfs源路径] [linux目的路径] #将文件从HDFS中移动到本地hdfs dfs -movetolocal [-crc] 从本地移动 6.查看文件内容 #利用管道符进行文件的查看hdfs dfs -cat path|查询范围#利用text命令查看文件内容hdfs dfs -text 查看文件内容#查看文件尾部信息hdfs dfs -tail [-f] #查看文件头部信息hdfs dfs -head [-f] 7.创建目录 #创建多级文件目录hdfs dfs -mkdir -p path1/path2 8.修改副本数量修改hadoop备份的副本数量，默认是三份
#修改hadoop备份的副本数量hdfs dfs -setrep [-r] [-w] 9.创建空白文件（不推荐使用）利用-touchz命令创建空白文件的过程中可能会产生错误，因此不推荐使用这个命令
#在指定路径上创建创建空白文件hdfs dfs -touchz 10.显示文件统计信息 #显示文件统计信息hdfs dfs -stat -stat [format] #------------------2023-12-29 04:25:27#------------------ 11、修改权限 #修改文件权限hdfs dfs -chmod [-r] [路径]#修改文件的所有者hdfs dfs -chown [-r] [属主][:[属组]] 路径 #修改文件所属的用户组hdfs dfs -chgrp [-r] 属组名称 路径 12、查看指令的帮助信息 #查看指令的帮助信息hdfs dfs -help [命令选项]
