CODEWITHSUNDEEP
linuxhadooppermissionshdfs
Abhinav
Abhinav

Reputation: 666

How to edit a HDFS group?

I have a standalone cluster for practice purpose. I tried to add the root user to hdfs group by logging in as an HDFS user.

The command I used is:

hdfs dfs -chown -R root:hdfs /

Now, I am able to access hdfs dfs commands as a root. But I don't know how to delete root from HDFS group. I tried this command as hdfs user:

hdfs dfs -chown -R hdfs:hdfs /

and

groups

command as a root user. But root is not added to any other group except for it's Primary group.

How am I supposed to change it back to the way it was?

Upvotes: 1

Views: 5614

Answers (2)

sujit
sujit

Reputation: 2328

By doing hdfs dfs -chown -R <user>:<group> you are not adding any user to any group.
Rather you are changing the directory/file permissions recursively from the / directory.

I think you can try hdfs dfs -chown -R hdfs:hdfs / logged in as hdfs. Then it should go back to previous state.

Upvotes: 3

OneCricketeer
OneCricketeer

Reputation: 191738

Groups and users don't physically "exist" in HDFS. They only exist on the local operating system. (Assuming you're not using Kerberos + LDAP).

You didn't add anything. You just changed a metadata tag ownership of an HDFS file path. And if you have ACLs and permissions disabled anyway as part of the default properties, these aren't checked.

The namenode(s) are where you would establish user groups using appropriate groupadd and useradd commands on the OS, but the root user is part of all *nix groups, so I'm not sure why you'd want to delete it rather than just prevent access.

Upvotes: 0

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