[beifeng@beifeng-hadoop- hadoop-2.5.]$ bin/hdfs dfs

Usage: hadoop fs [generic options]

        [-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 | -p[topax]] <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>]

        [-getfattr [-R] {-n name | -d} [-e en] <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>]]

        [-setfattr {-n name [-v value] | -x name} <path>]

        [-setrep [-R] [-w] <rep> <path> ...]

        [-stat [format] <path> ...]

        [-tail [-f] <file>]

        [-test -[defsz] <path>]

        [-text [-ignoreCrc] <src> ...]

        [-touchz <path> ...]

        [-usage [cmd ...]]

Generic options supported are

-conf <configuration file>     specify an application configuration file

-D <property=value>            use value for given property

-fs <local|namenode:port>      specify a namenode

-jt <local|jobtracker:port>    specify a job tracker

-files <comma separated list of files>    specify comma separated files to be copied to the map reduce cluster

-libjars <comma separated list of jars>    specify comma separated jar files to include in the classpath.

-archives <comma separated list of archives>    specify comma separated archives to be unarchived on the compute machines.

The general command line syntax is

bin/hadoop command [genericOptions] [commandOptions]

[beifeng@beifeng-hadoop- hadoop-2.5.]$ bin/hdfs

Usage: hdfs [--config confdir] COMMAND

       where COMMAND is one of:

  dfs                  run a filesystem command on the file systems supported in Hadoop.

  namenode -format     format the DFS filesystem

  secondarynamenode    run the DFS secondary namenode

  namenode             run the DFS namenode

  journalnode          run the DFS journalnode

  zkfc                 run the ZK Failover Controller daemon

  datanode             run a DFS datanode

  dfsadmin             run a DFS admin client

  haadmin              run a DFS HA admin client

  fsck                 run a DFS filesystem checking utility

  balancer             run a cluster balancing utility

  jmxget               get JMX exported values from NameNode or DataNode.

  oiv                  apply the offline fsimage viewer to an fsimage

  oiv_legacy           apply the offline fsimage viewer to an legacy fsimage

  oev                  apply the offline edits viewer to an edits file

  fetchdt              fetch a delegation token from the NameNode

  getconf              get config values from configuration

  groups               get the groups which users belong to

  snapshotDiff         diff two snapshots of a directory or diff the

                       current directory contents with a snapshot

  lsSnapshottableDir   list all snapshottable dirs owned by the current user

                                                Use -help to see options

  portmap              run a portmap service

  nfs3                 run an NFS version  gateway

  cacheadmin           configure the HDFS cache

Most commands print help when invoked w/o parameters.

[beifeng@beifeng-hadoop- hadoop-2.5.]$ bin/hdfs dfsadmin

Usage: java DFSAdmin

Note: Administrative commands can only be run as the HDFS superuser.

           [-report]

           [-safemode enter | leave | get | wait]

           [-allowSnapshot <snapshotDir>]

           [-saveNamespace]

           [-rollEdits]

           [-restoreFailedStorage true|false|check]

           [-refreshNodes]

           [-finalizeUpgrade]

           [-rollingUpgrade [<query|prepare|finalize>]]

           [-metasave filename]

           [-refreshServiceAcl]

           [-refreshUserToGroupsMappings]

           [-refreshSuperUserGroupsConfiguration]

           [-refreshCallQueue]

           [-refresh]

           [-printTopology]

           [-refreshNamenodes datanodehost:port]

           [-deleteBlockPool datanode-host:port blockpoolId [force]]

           [-setQuota <quota> <dirname>...<dirname>]

           [-clrQuota <dirname>...<dirname>]

           [-setSpaceQuota <quota> <dirname>...<dirname>]

           [-clrSpaceQuota <dirname>...<dirname>]

           [-setBalancerBandwidth <bandwidth in bytes per second>]

           [-fetchImage <local directory>]

           [-shutdownDatanode <datanode_host:ipc_port> [upgrade]]

           [-getDatanodeInfo <datanode_host:ipc_port>]

           [-help [cmd]]

Generic options supported are

-conf <configuration file>     specify an application configuration file

-D <property=value>            use value for given property

-fs <local|namenode:port>      specify a namenode

-jt <local|jobtracker:port>    specify a job tracker

-files <comma separated list of files>    specify comma separated files to be copied to the map reduce cluster

-libjars <comma separated list of jars>    specify comma separated jar files to include in the classpath.

-archives <comma separated list of archives>    specify comma separated archives to be unarchived on the compute machines.

The general command line syntax is

bin/hadoop command [genericOptions] [commandOptions]

[beifeng@beifeng-hadoop- hadoop-2.5.]$

[beifeng@beifeng-hadoop- hadoop-2.5.]$ bin/hdfs dfsadmin

Usage: java DFSAdmin

Note: Administrative commands can only be run as the HDFS superuser.

           [-report]

           [-safemode enter | leave | get | wait]

           [-allowSnapshot <snapshotDir>]

           [-disallowSnapshot <snapshotDir>]

           [-saveNamespace]

           [-rollEdits]

           [-restoreFailedStorage true|false|check]

           [-refreshNodes]

           [-finalizeUpgrade]

           [-rollingUpgrade [<query|prepare|finalize>]]

           [-metasave filename]

           [-refreshServiceAcl]

           [-refreshUserToGroupsMappings]

           [-refreshSuperUserGroupsConfiguration]

           [-refreshCallQueue]

           [-refresh]

           [-printTopology]

           [-refreshNamenodes datanodehost:port]

           [-deleteBlockPool datanode-host:port blockpoolId [force]]

           [-setQuota <quota> <dirname>...<dirname>]

           [-clrQuota <dirname>...<dirname>]

           [-setSpaceQuota <quota> <dirname>...<dirname>]

           [-clrSpaceQuota <dirname>...<dirname>]

           [-setBalancerBandwidth <bandwidth in bytes per second>]

           [-fetchImage <local directory>]

           [-shutdownDatanode <datanode_host:ipc_port> [upgrade]]

           [-getDatanodeInfo <datanode_host:ipc_port>]

           [-help [cmd]]

Generic options supported are

-conf <configuration file>     specify an application configuration file

-D <property=value>            use value for given property

-fs <local|namenode:port>      specify a namenode

-jt <local|jobtracker:port>    specify a job tracker

-files <comma separated list of files>    specify comma separated files to be copied to the map reduce cluster

-libjars <comma separated list of jars>    specify comma separated jar files to include in the classpath.

-archives <comma separated list of archives>    specify comma separated archives to be unarchived on the compute machines.

The general command line syntax is

bin/hadoop command [genericOptions] [commandOptions]

[beifeng@beifeng-hadoop- hadoop-2.5.]$ bin/hdfs dfsadmin -safemode

Usage: java DFSAdmin [-safemode enter | leave | get | wait]