Linux 102|107 Admin

Guide

Topic 107: Administrative Tasks

107.1 Manage user and group accounts and related system files

Weight: 5

Key Knowledge Areas:

• • Add, modify and remove users and groups

  • Manage user/group info in password/group databases

  • Create and manage special purpose and limited accounts

Terms and Utilities:

MANAGE USER AND GROUP ACCOUNTS AND RELATED FILE SYSTEM

/etc/passwd /etc/shadow /etc/group /etc/skel

usedadd usermod userdel groupadd groupdel groupmod

chage passwd

USER ACCOUNTS

Each user will usually have their own account to the Linux System

The account will normally have a password

User accounts are stored in /etc/passwd

Password in /etc/shadow

User accounts are managed with

useradd

userdel

usermod

User ID Numbers below 100 are reserved for system accounts

/etc/skel

When users are created with useradd and their home directories, created, the contents on that home directory is copied from the skeleton directory /etc/skel

Any files you would like to be created in alll new users home directories then they can be added to /etc/skel

Adding files or content to /etc/skel does not effect existing user directories

GROUP ACCOUNTS

Group Accounts can simplify user access by allowing access to a group rather than each user

Group Accounts are stored in /etc/group

Group Accounts are managed with

groupadd

groupdel

groupmod

rex@bunturx:~$ id uid=1000(rex) gid=1000(rex) groups=1000(rex),4(adm),24(cdrom),27(sudo),30(dip),46(plugdev),111(lpadmin),112(sambashare)

rex@bunturx:~$ touch newfile rex@bunturx:~$ ls -l newfile -rw-rw-r-- 1 rex rex 0 Dec 15 12:37 newfile

rex@bunturx:~$ tail /etc/passwd syslog:x:101:103::/home/syslog:/bin/false messagebus:x:102:105::/var/run/dbus:/bin/false whoopsie:x:103:106::/nonexistent:/bin/false landscape:x:104:109::/var/lib/landscape:/bin/false rex:x:1000:1000:rex lacson,,,:/home/rex:/bin/bash sshd:x:105:65534::/var/run/sshd:/usr/sbin/nologin uno:x:1001:1001:uno ware,202020,404040,555 666 123,none:/home/uno:/bin/bash debian-tor:x:106:113::/var/lib/tor:/bin/bash postfix:x:107:115::/var/spool/postfix:/bin/false anthony:x:1002:1002::/home/anthony:/bin/sh

107.2 Automate system administration tasks by scheduling jobs

Weight: 4

Key Knowledge Areas:

• • Manage cron and at jobs

  • Configure user access to cron and at services

  • Configure anacron

Terms and Utilities:

107.3 Localisation and internationalisation

Weight: 3

Key Knowledge Areas:

• • Configure locale settings and environment variables

  • Configure timezone settings and environment variables

Terms and Utilities:

eof