New user group, user, user password, delete user group, user (for CentOS, Ubuntu)

This knowledge point, blurred for a long time.

In production, the habit is as follows:

Useradd, the default is to add a new user to the user group with the same name. For example, Useradd zhouls, after this command is executed, is added to the Zhouls user group with the same name by default.

However, in production, generally do not do so. Usually,useradd-m-G . Otherwise, when it appears, the user is established, but the home directory does not appear oh. Careful!!! (important words, say three times)

################### #CentOS系统里 ##########################

In the CentOS system, the root user executes the

First step:groupadd new user group

Groupadd Hadoop This is the creation of a Hadoop user group

Step Two:useradd-m-G created user group New user

Useradd-m-G Hadoop Hadoop This is a new Hadoop user and home directory also created and added to the Hadoop group

Step three:passwd has created a user

passwd Hadoop Hadoop User Password

Changing password for user Hadoop

New Password:

Retype new Password:

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################## #Ubuntu系统里 ###########################

Ubuntu system, root user execution, first how to open, see Ubuntu14.04 after installation of some configuration

First step:sudo groupadd new user group

sudo groupadd Spark This is the Create Spark user group

Step two:sudo useradd-m-G created user group New user

sudo useradd-m-G spark Spark This is a new spark user and home directory also created and added to the Spark group

Step three:sudo passwd user created

passwd Spark Spark User password

Changing password for user spark

New Password:

Retype new Password:

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deleted, here, not much to repeat. corresponding to, for Userdel, can.

Modified, here, also not much to repeat. corresponding to, for Usermod, can.

　　

New user group, user, user password, delete user group, user (for CentOS, Ubuntu)