Hadoop FS Chmod

In Hadoop HDFS (Hadoop Distributed File System), you can use the hadoop fs -chmod command to change the permissions of files and directories, similar to the chmod command in Unix-like file systems. This command allows you to control who can read, write, and execute files in HDFS. Here’s the basic syntax for using hadoop fs -chmod:

• <permissions>: A three-digit octal number that represents the new permissions you want to set for the file or directory. Each digit corresponds to read (4), write (2), and execute (1) permissions for the owner, group, and others. For example, 755 means read, write, and execute for the owner and read and execute for the group and others.
• <path>: The path to the file or directory in HDFS whose permissions you want to change.

Here are some examples of how to use hadoop fs -chmod:

1. To give read and execute permissions to the owner and read-only permissions to the group and others for a file named “datafile.txt” in HDFS:

2. To make a directory named “mydir” in HDFS writable by the owner and read-only for others:

3. To remove all permissions for the group and others on a directory named “logs”:

4. To give read and execute permissions to the owner and group and no permissions to others for all files in a directory:

The -R option is used for recursive permission changes, applying the specified permissions to all files and subdirectories within the given directory.