Several common commands of hadoop
Official document: http://hadoop.apache.org/docs/r1.2.1/file_system_shell.html
1. Log in to the primary node and switch to the hdfs user
[hdfs@cdhm1~] # su-hdfs
2. List the subdirectories and files of the current directory
[hdfs@cdhm1] $hadoop fs-ls / Found 2 itemsdrwxrwxrwt-hdfs supergroup 02017-05-23 16:39 / tmpdrwxr-xr-x-hdfs supergroup 02017-05-24 15:45 / user
3. In the Hadoop file system, create a test directory
[hdfs@cdhm1 ~] $hadoop fs-mkdir / user/hdfs/test
Check that there is a test directory under the directory, and it is created successfully.
[hdfs@cdhm1] $hadoop fs-ls / user/hdfs/Found 4 itemsdrwx--hdfs supergroup0 2017-05-26 08:00 / user/hdfs/.Trashdrwxr-xr-x-hdfs supergroup0 2017-06-05 15 15 paste 19Greater hdfsax. SparkStagingdrwx-- hdfs supergroup0 2017-05-24 15:46/user/hdfs/.stagingdrwxr-xr-x-hdfs supergroup0 2017-07-03 10:19 / user/hdfs/test
4. Delete the test directory
[hdfs@cdhm1 ~] $hadoop fs-rmr / user/hdfs/test17/07/03 10:46:06INFO fs.TrashPolicyDefault: Namenode trash configuration: Deletion interval = 1440 minutes, Emptier interval = 0 minutes.Moved:'hdfs://cdhm1:8020/user/hdfs/test' to trash at:hdfs://cdhm1:8020/user/hdfs/.Trash/Current
Check again that the test directory is gone.
[hdfs@cdhm1] $hadoop fs-ls / user/hdfs/Found 3 itemsdrwx--hdfs supergroup 0 2017-07-03 10:46 / user/hdfs/.Trashdrwxr-xr-x-hdfs supergroup 0 2017-06-05 1515 19UserUserUserCharger hdfsscar.sparkStagingdrwx-- hdfs supergroup 0 2017-05-24 15:46/user/hdfs/.staging
5. Download the files in the Hadoop file system to the local
[hdfs@cdhm1 ~] $hadoop fs-get / user/hdfs/test2
Check the local test2 download successfully
[hdfs@cdhm1 ~] $lstest2 test.txt
Upload local files to the Hadoop file system
[hdfs@cdhm1 ~] $hadoop fs-put test.txt / user/hdfs/
Check that test.txt has been uploaded successfully in hadoop
[hdfs@cdhm1] $hadoop fs-ls / user/hdfs/Found 5 itemsdrwx--hdfs supergroup 0 2017-07-03 10:46 / user/hdfs/.Trashdrwxr-xr-x-hdfs supergroup 0 2017-06-05 1515 hdfs 19user hdfs hdfs.sparkStagingdrwx-- hdfs supergroup 0 2017-05-24 15lace 46hand username hdfshand. Supergroup 0 2017-07-03 11:13 / user/hdfs/test.txtdrwxr-xr-x-hdfs supergroup 0 2017-07-03 11:04 / user/hdfs/test2
