User and Group Administration - Part 2

GROUP ADMINISTRATION

Few Restrictions on the Group Name:

1. Group names cannot start with the below signs:

• Dash or minus sign (-).
• Plus sign (+)
• At symbol (@)
• Tilde (~)

2. Groups cannot be named ALL or default, as these names are reserved for the AIX OS.
 
3. Group names cannot include :

• Colon (:)  
• Quotation marks—single or double (' or ")
• Pound or hash sign (#)
• Comma (,)
• Equal sign (=)
• Slashes—back or forward (\ or /)
• Question mark (?)
• Back quote or tick (`)
• White space (space or tab)
• New-line characters

4.  Group names can have max. 8 characters in AIX V 5.2 or earlier. Starting with AIX 5.3, you can have a
max. of 255 characters.



Now let us look at the configuration files for groups.


/etc/group :

This file contains the basic group configuration details in the following format.

Group Name : Password Flag : GID : User(s)

where
Password Flag - This field is not used in AIX.
GID                 - Group ID is the unique identification number for every group. 0 is the gid for system group.
User(s)             - List of users belonging to the group

/etc/security/group :

This file contains the extended attribtues for the groups.
Here are the parameters used in this file.

adms  - List of users with admin rights to ths group
admin - If set to true, this group will have administrative rights.

There are 4 main commands used in the administration of group :

mkgroup - Add a group
chgroup - Change an attribtue of a group
lsgroup  - List the attribtues of a group
rmgroup - Remove a group

These words can also be used as fastpaths for smitty.

For example, # smitty mkgroup will open a form to create a group.

For doing the whole group administration, you can use

# smitty group and go thru the menu items for various operations.


Now let us see the commands to administrate groups ...

1. To create a group called dba :

# mkgroup dba

2. To create a admin group called admin1 :

# mkgroup -a admin1

3. To create dba group and add jack as the admin :

# mkgroup adms=jack dba

4. To change the members of dba group, you can use any of the below commands :

# chgroup users=jack,tom,michelle dba

# chgrpmem dba

# chgrpmem -m + raja dba

5. To remove the membership of a user from the dba group :

# chgrpmem -m - jack dba

6. To add a user as admin for the dba group :

# chgrpmem -a + raja dba

7. To remove the group administrator :

# chgrpmem -a - raja dba

8. To list the attributes of a group :

# lsgroup dba

9. To remove a group from the system :

# rmgroup test