#-->root user

$-->regular user

Web console is a system administration tool that provides a user interface for monitoring and administering servers through a web browser.

Web console enables to perform these tasks:

Monitoring basic system features, such as hardware, internet connection, or performance characteristics
Analyzing the content of the system log files
Configuring basic networking features, such as interfaces, network logs, packet sizes
Managing user accounts
Monitoring and configuring system services
Creating diagnostic reports
Setting kernel dump configuration Configuring SELinux
Managing system subscriptions
Accessing the terminal

Configuring the Date and Time:NTP protocol

chronyd The chronyd daemon is used by default. It is available from the chrony package.

ntpd The ntpd daemon is available from the ntp package.

Displaying the Current Date and Time:

~]$ date

~]$ timedatectl

Configuring the System Locale

System-wide locale settings are stored in the /etc/locale.conf file, which is read at early boot by the systemd daemon.

Listing available system locale settings:

~]$ localectl list-locales

Displaying current status of the system locales settings:

~]$ localectl status

Setting or changing the default system locale settings:

~]# localectl set-locale LANG=locale

Configuring the Keyboard Layout

Listing available keymaps:

~]$ localectl list-keymaps

Displaying current status of keymap settings:

~]$ localectl status

Setting or changing the default system keymap:

~]# localectl set-keymap

CONFIGURING AND INSPECTING NETWORK ACCESS: nmcli and nmutui

Managing Network Connections After the Installation Process Using :nmcli

To create a new connection:

~]# nmcli con add type type of the connection "con-name" connection name ifname ifname interfacename the name of the interface ipv4 address ipv4 address gw4 address gateway address

To modify the existing connection:

~]# nmcli con mod "con-name"

To display all connections:

~]# nmcli con show

To display the active connection:

~]# nmcli con show --active

To display all configuration settings of a particular connection:

~]# nmcli con show "con-name"

Using nmtui(NetworkManager text user interface (TUI) utility)

Managing Networking in web console

Registering the System after the Installation

~]# subscription-manager register

The command will prompt you to enter your Red Hat Customer Portal user name and password.

2. Determine the pool ID of a subscription that you require:

~]# subscription-manager list --available

This command displays all available subscriptions for your Red Hat account. For every subscription, various characteristics are displayed, including the pool ID.

3. Attach the appropriate subscription to your system by replacing pool_id with the pool ID determined in the previous step:

~]# subscription-manager attach --pool=pool_id

Registering a System to EUS Content

To access the Extended Update Support (EUS) content, register your system as follows:

Verify that EUS entitlements are available:

 ~]# subscription-manager list --available --matches="*Extended Update Support"

Attach the applicable subscription using the Pool identifier:

  ~]# subscription-manager attach --pool 8a99f9ac7238188b01723d9c8a8a06a9

Replace the default repositories enabled for the system with the EUS variants:
```
 ~]# subscription-manager repos --disable *
```
Enable the repositories which represent the EUS content set for the RHEL revision in use:
```
 ~]# subscription-manager repos --enable rhel-7-server-eus-rpms
```
Select the required and supported release for the end system:
1. ```
 ~]# subscription-manager release --set 7.6
```

Registering a System to E4S Content

Verify that E4S entitlements are available:

 ~]# subscription-manager list --available --matches="Update Services for SAP Solutions"

Attach the applicable subscription using the Pool identifier:
```
 ~]# subscription-manager attach --pool=#################
```
Replace the default repositories enabled for the system with the EUS variants:
```
  ~]# subscription-manager repos --disable="*"
```
Enable the repositories which represent the E4S content set for the RHEL revision in use:
```
 ~]# subscription-manager --enable=rhel-7-server-e4s-rpms
```
Clear the repository cache and release lock the system to a valid release for E4S which supports your SAP application:
```
 ~]# yum clean all && subscription-manager release --set=7.7
```

INSTALLING SOFTWARE

When a system is subscribed to the Red Hat Content Delivery Network, a repository file is created in the /etc/yum.repos.d/ directory.

Use the yum utility to manage package operations:

1.Searching information about packages

2.Installing packages

3.Updating packages

4.Removing packages

5.Checking the list of currently available repositories

6.Adding or removing a repository

7.Enabling or disabling a repository

Managing Basic Software Installation Tasks with Subscription Manager and Yum

Listing all available repositories:

~]# subscription-manager repos --list

Listing all currently enabled repositories:

~]$ yum repolist

Enabling or disabling a repository:

~]# subscription-manager repos --enable repository

~]# subscription-manager repos --disable repository

Searching for packages matching a specific string:

~]$ yum search string

Installing a package:

~]# yum install package_name

Updating all packages and their dependencies:

~]# yum update

Updating a package:

~]# yum update package_name

Uninstalling a package and any packages that depend on it:

~]# yum remove package_name

Listing information on all installed and available packages:

~]$ yum list all

Listing information on all installed packages:

~]$ yum list installed

Enabling or Disabling the Services

~]# systemctl enableservice_name
~]# systemctl disableservice_name

What SELinux Is and How It Enhances System Security

Security Enhanced Linux (SELinux) is an additional layer of system security that determines which process can access which files, directories, and ports.

SELinux States SELinux has two possible states:

Enabled

Disabled

When SELinux is disabled, only Discretionary Access Control (DAC) rules are used.

SELinux Modes

When SELinux is enabled, it can run in one of the following modes:

Enforcing

Permissive

Enforcing mode means that SELinux policies is enforced.

SELinux denies access based on SELinux policy rules, and enables only the interactions that are particularly allowed.

Enforcing mode is the default mode after the installation and it is also the safest SELinux mode.

Permissive mode means that SELinux policies is not enforced.

SELinux does not deny access, but denials are logged for actions that would have been denied if running in enforcing mode.

Permissive mode is the default mode during the installation.

Ensuring the Required State of SELinux

Display the current SELinux mode in effect:

~]$ getenforce

2. If needed, switch between the SELinux modes. The switch can be either temporary or permanent. A temporary switch is not persistent across reboots, while permanent switch is. To temporary switch to either enforcing or permissive mode:

~]# setenforce Enforcing

~]# setenforce Permissive

To permanently set the SELinux mode, modify the SELINUX variable in the /etc/selinux/config configuration file.

Managing SELinux in web console

Secure Shell (SSH)

Secure Shell (SSH) is a protocol which facilitates client-server communication and allows users to log in to any host system running SSH remotely. SSH encrypts the connection. The client transmits its authentication information to the server using encryption, and all data sent and received during a session are transferred under the encryption.

Creating the Key Files and Copying Them to the Server

~]$ ssh-keygen

Both keys are stored in the

~/.ssh/ directory:

~/.ssh/id_rsa.pub - public key

~/.ssh/id_rsa - private key

Copy the most recently modified public key to a remote machine you want to log into:

~]# ssh-copy-id USER@hostname

Disabling SSH Root Login

Access the /etc/ssh/sshd_config file:
```
 ~]# vi /etc/ssh/sshd_config
```
Change the line that reads

#PermitRootLogin yes <--to:--> PermitRootLogin no

Restart the sshd service:

~]# systemctl restart sshd

Most Basic Command-Line Tools to Manage User Accounts and Groups

Displaying user and group IDs:

```
 ~]# id
```

Creating a new user account:

~]# useradd [options] user_name

Assigning a new password to a user account belonging to username:

~]# passwd user_name

Adding a user to a group:

~]# usermod -a -G group_name user_name

Managing User Accounts in web console

What kdump Is and Which Tasks It Can Be Used

For In case of a system crash, you can use the Kernel crash dump mechanism called kdump that enables you to save the content of the system’s memory for later analysis.

The kdump mechanism relies on the kexec system call, which can be used to boot a Linux kernel from the context of another kernel, bypass BIOS, and preserve the contents of the first kernel’s memory that would otherwise be lost.

When kernel crash occurs, kdump uses kexec to boot into a second kernel (a capture kernel), which resides in a reserved part of the system memory that is inaccessible to the first kernel.

Ensuring That kdump Is Installed and Enabled

To check whether kdump is installed on your system:
```
 ~]$ rpm -q kexec-tools
```
If not installed, to install kdump, enter as the root user:
```
 ~]# yum install kexec-tools
```
If you need to install the graphical configuration tool:
```
 ~]# yum install system-config-kdump
```
ReaR Is and Which Tasks It Can Be Used For

ReaR is a disaster recovery and system migration utility which enables you to create the complete rescue system.

ReaR enables to perform the following tasks:

Booting a rescue system on the new hardware

Replicating the original storage layout

Restoring user and system files

To install ReaR, enter as the root user:
```
  ~]# yum install rear
```
/etc/rear/local.conf file to configure ReaR.

Quickstart to Creation of the Rescue System with ReaR
```
  ~]# rear mkrescue
```
To make ReaR use its internal backup method, add these lines to the /etc/rear/local.conf file:

BACKUP=NETFS

BACKUP_URL=backup location

USING THE LOG FILES TO TROUBLESHOOT PROBLEMS

Services Handling the syslog Messages

The syslog messages are handled by two services:

the systemd-journald daemon -

Collects messages from the kernel,

the early stages of the boot process,

standard output and error of daemons as they start up and run, and syslog, and forwards the messages to the rsyslog service for further processing. the rsyslog service - Sorts the syslog messages by type and priority, and writes them to the files in the /var/log directory, where the logs are persistently stored.

Subdirectories Storing the syslog Messages The syslog

var/log/messages - all syslog messages except those mentioned below var/log/secure - security and authentication-related messages and errors var/log/maillog - mail server-related messages and errors var/log/cron - log files related to periodically executed tasks var/log/boot.log - log files related to system startup

CHAPTER 2. SYSTEM LOCALE AND KEYBOARD CONFIGURATION

Modifying the /etc/locale.conf configuration file or by using the localectl utility.

Option Description

LANG Provides a default value for the system locale.

LC_COLLATE Changes the behavior of functions which compare

strings in the local alphabet.

LC_CTYPE Changes the behavior of the character handling and

classification functions and the multibyte character

functions.

LC_NUMERIC Describes the way numbers are usually printed, with

details such as decimal point versus decimal comma.

LC_TIME Changes the display of the current time, 24-hour

versus 12-hour clock.

LC_MESSAGES Determines the locale used for diagnostic messages

written to the standard error output.

Displaying the Current Status

localectl status

Listing Available Locales

localectl list-locales

Setting the Locale

To set the default system locale, use the following command as root:

localectl set-locale LANG=locale

Changing the Default Locale

 ~]# localectl set-locale LANG=en_GB.utf8

CHANGING THE KEYBOARD LAYOUT

localectl status

Listing Available Keymaps

localectl list-keymaps

Searching for a Particular Keymap

localectl list-keymaps | grep cz

Setting the Keymap

 localectl set-keymap map

CHAPTER 3. CONFIGURING THE DATE AND TIME

The timedatectl utility, which is new in Red Hat Enterprise Linux 7 and is part of systemd.

The traditional date command.

The hwclock utility for accessing the hardware clock.

USING THE TIMEDATECTL COMMAND

Displaying the Current Date and Time

timedatectl

Network Time Protocol (NTP) configuration

~]# systemctl restart systemd-timedated.service

Changing the Current Time

To change the current time, type the following at a shell prompt as root:

timedatectl set-time HH:MM:SS

The result it is similar to using both the date --set and hwclock --systohc commands.

To configure your system to maintain the clock in the local time, run the timedatectl command with the set-local-rtc option as root:

timedatectl set-local-rtc boolean

Changing the Current Date

timedatectl set-time YYYY-MM-DD

Changing the Current Date

~]# timedatectl set-time "2017-06-02 23:26:00"

Changing the Time Zone

To list all available time zones, type the following at a shell prompt:

timedatectl list-timezones

To change the currently used time zone, type as root:

timedatectl set-timezone time_zone

To change the time zone to Europe/Prague, type as root:

~]# timedatectl set-timezone Europe/Prague

Synchronizing the System Clock with a Remote Server

the timedatectl command also allows you to enable automatic synchronization of your system clock with a group of remote servers.

timedatectl set-ntp boolean

 ~]# timedatectl set-ntp yes

USING THE DATE COMMAND

Displaying the Current Date and Time

date
date --utc
date --u

You can also customize the format of the displayed information by providing the +"format" option on the command line:

date +"format"

Commonly Used Control Sequences

Control Sequence Description

%H The hour in the HH format (for example, 17).

%M The minute in the MM format (for example, 30).

%S The second in the SS format (for example, 24).

%d The day of the month in the DD format (for example,

16).

%m The month in the MM format (for example, 09).

%Y The year in the YYYY format (for example, 2016).

%Z The time zone abbreviation (for example, CEST).

%F The full date in the YYYY-MM-DD format (for

example, 2016-09-16). This option is equal to %Y-

%m-%d.

%T The full time in the HH:MM:SS format (for exam

Changing the Current Time

To change the current time, run the date command with the --set or -s option as root:

date --set HH:MM:SS
date --set HH:MM:SS --utc

Changing the Current Date

date --set YYYY-MM-DD
~]# date --set "2017-06-02 23:26:00"

USING THE HWCLOCK COMMAND

Displaying the Current Date and Time:hwclock

Setting the Date and Time

hwclock --set --date "dd mmm yyyy HH:MM"

Setting the Hardware Clock to a Specific Date and Time

~]# hwclock --set --date "21 Oct 2016 21:17" --utc

Synchronizing the Date and Time

hwclock --systohc
hwclock --hctosys

Synchronizing the Hardware Clock with System Time

~]# hwclock --systohc --localtime

CHAPTER 4. MANAGING USERS AND GROUPS

Each user is associated with a unique numerical identification number called a user ID (UID). Likewise, each group is associated with a group ID (GID).

Reserved User and Group IDs

cat /usr/share/doc/setup*/uidgid
/etc/login.defs

A list of all groups is stored in the /etc/group configuration file.

Shadow Passwords

In environments with multiple users, it is very important to use shadow passwords provided by the shadow-utils package to enhance the security of system authentication files.

Shadow passwords improve system security by moving encrypted password hashes from the world-readable /etc/passwd file to /etc/shadow, which is readable only by the root user.

The gpasswd utility for administrating the /etc/group file.

The usermod command with the -e, --expiredate or -f, --inactive option.

The useradd command with the -e, --expiredate or -f, --inactive option

The Super key appears in a variety of guises, depending on the keyboard

USING COMMAND-LINE TOOLS

Utilities	Description
id	Displays user and group IDs.
useradd, usermod, userdel	Standard utilities for adding, modifying, and deleting user accounts.

groupadd, groupmod, groupdel	Standard utilities for adding, modifying, and deleting groups.

gpasswd	Utility primarily used for modification of group password in the */etc/gshadow* file which is used by the *newgrp* command.
pwck, grpck	Utilities that can be used for verification of thepassword, group, and associated shadow files.
pwconv, pwunconv	Utilities that can be used for the conversion of passwords to shadow passwords, or back from shadow passwords to standard passwords.

grpconv, grpunconv Similar to the previous, these utilities can be used for conversion of shadowed information for group accounts.

Adding a New User

useradd options username
passwd username(adding password to username)

Adding a New Group

Adding an Existing User to an Existing Group

To override user’s primary group, run the following command as root:

~]# usermod -g group_name user_name

To override user’s supplementary groups, run the following command as root:

~]# usermod -G group_name1,group_name2,... user_name

Note that in this case all previous supplementary groups of the user are replaced by the new group or several new groups.

To add one or more groups to user’s supplementary groups, run one of the following commands as root:

~]# usermod -aG group_name1,group_name2,... user_name 
~]# usermod --append -G group_name1,group_name2,... user_name

Creating Group Directories

As root, create the /opt/myproject/ directory by typing the following at a shell prompt:

mkdir /opt/myproject

2. Add the myproject group to the system:

 groupadd myproject

3. Associate the contents of the /opt/myproject/ directory with the myproject group:

chown root:myproject /opt/myproject

4. Allow users in the group to create files within the directory and set the setgid bit:

chmod 2775 /opt/myproject

At this point, all members of the myproject group can create and edit files in the /opt/myproject/ directory without the administrator having to change file permissions every time users write new files. To verify that the permissions have been set correctly, run the following command:

~]# ls -ld /opt/myproject

5. Add users to the myproject group:

usermod -aG myproject username

Setting Default Permissions for New Files Using umask

-rw-rw-r--

bash has umask 0022 by default

A umask consists of bits corresponding to standard file permissions. For example, for umask 0137,

the digits mean that: 0 = no meaning, it is always 0 (umask does not affect special bits)

1 = for owner permissions, the execute bit is set

3 = for group permissions, the execute and write bits are set

7 = for others permissions, the execute, write, and read bits are set

Displaying the current mask :

 ~]$ umask 
To show the current umask in symbolic notation:
~]$ umask -S
To set umask for the current shell session using octal notation run:
~]$ umask octal_mask
Setting umask Using Octal Notation
~]$ umask 0337
To set umask for the current shell session using symbolic notation:
~]$ umask -S symbolic_mask
Setting umask Using Symbolic Notation
~]$ umask -S u=r,g=r,o=
Shells usually have a configuration file where their default umask is set. For bash, it is /etc/bashrc. To
show the default bash umask:
~]$ grep -i -B 1 umask /etc/bashrc
The output shows if umask is set, either using the umask command or the UMASK variable. In the
following example, umask is set to 022 using the umask command:
~]$ grep -i -B 1 umask /etc/bashrc
# By default, we want umask to get set. This sets it for non-login shell.
--
if [ $UID -gt 199 ] && [ “id -gn” = “id -un” ]; then
umask 002
else
umask 022
To change the default umask for bash, change the umask command call or the UMASK variable
assignment in /etc/bashrc. This example changes the default umask to 0227:
if [ $UID -gt 199 ] && [ “id -gn” = “id -un” ]; then
CHAPTER 4. MANAGING USERS AND GROUPS
71
umask 002
else
umask 227
Working with the default shell umask of a specific user
By default, bash umask of a new user defaults to the one defined in /etc/bashrc.
To change bash umaskfor a particular user, add a call to the umask command in $HOME/.bashrc file of
that user. For example, to change bash umask of user john to 0227:
john@server ~]$ echo 'umask 227' >> /home/john/.bashrc
Setting default permissions for newly created home directories
To change permissions with which user home directories are created, change the UMASK variable in the
/etc/login.defs file:
# The permission mask is initialized to this value. If not specified,
# the permission mask will be initialized to 022.
UMASK 077

ADDITIONAL RESOURCES

CHAPTER 5. ACCESS CONTROL LISTS

Along with support in the kernel, the acl package is required to implement ACLs. It contains the utilities used to add, modify, remove, and retrieve ACL information. The cp and mv commands copy or move any ACLs associated with files and directories.

MOUNTING FILE SYSTEMS

mount -t ext3 -o acl device-name partition
For example:
mount -t ext3 -o acl /dev/VolGroup00/LogVol02 /work

NFS By default, if the file system being exported by an NFS server supports ACLs and the NFS client can read ACLs, ACLs are utilized by the client system.

To disable ACLs on NFS shares when configuring the server, include the no_acl option in the /etc/exports file.

To disable ACLs on an NFS share when mounting it on a client, mount it with the no_acl option via the command line or the /etc/fstab file.

SETTING ACCESS ACLS

There are two types of ACLs: access ACLs and default ACLs. An access ACL is the access control list for a specific file or directory. A default ACL can only be associated with a directory; if a file within the directory does not have an access ACL, it uses the rules of the default ACL for the directory. Default ACLs are optional.

ACLs can be configured:

Per user
Per group
Via the effective rights mask
For users not in the user group for the file

The setfacl utility sets ACLs for files and directories. Use the -m option to add or modify the ACL of a file or directory:

setfacl -m rules files

Note:Multiple rules can be specified in the same command if they are separated by commas.

u:uid:perms
Sets the access ACL for a user. The user name or UID may be specified. The user may be any valid
user on the system.
g:gid:perms
Sets the access ACL for a group. The group name or GID may be specified. The group may be any
valid group on the system.
m:perms
Sets the effective rights mask. The mask is the union of all permissions of the owning group and all of
the user and group entries.
o:perms
Sets the access ACL for users other than the ones in the group for the file.
Permissions (perms) must be a combination of the characters r, w, and x for read, write, and execute.

Give read and write permissions For example, to give read and write permissions to user andrius:

setfacl -m u:andrius:rw /project/somefile

To remove all the permissions for a user, group, or others, use the -x option and do not specify any permissions:

setfacl -x rules files

Remove all permissions

For example, to remove all permissions from the user with UID 500:

setfacl -x u:500 /project/somefile

Setting default ACLs For example,

to set the default ACL for the /share/ directory to read and execute for users not in the user group (an access ACL for an individual file can override it):

setfacl -m d:o:rx /share

Retrieving ACLs

getfacl home/john/picture.png

ARCHIVING FILE SYSTEMS WITH ACLS

CHAPTER 6. GAINING PRIVILEGES

One of the simplest ways to do this is to add users to the special administrative group called wheel. To do this, type the following command as root: ~]#

usermod -a -G wheel username

You can also configure sudo users who do not need to provide any password by using the NOPASSWD option in the /etc/sudoers file:

user_name ALL=(ALL) NOPASSWD: ALL
sudo /bin/bash

ADDITIONAL RESOURCES

su(1) — The manual page for su provides information regarding the options available with this command.

sudo(8) — The manual page for sudo includes a detailed description of this command and lists options available for customizing its behavior.

pam(8) — The manual page describing the use of Pluggable Authentication Modules (PAM) for Linux.

REGISTERING THE SYSTEM AND MANAGING SUBSCRIPTIONS

Run the following command to register your system. You will be prompted to enter your user name and password. Note that the user name and password are the same as your login credentials for Red Hat Customer Portal.

subscription-manager register

Determine the pool ID of a subscription that you require. To do so, type the following at a shell prompt to display a list of all subscriptions that are available for your system:

subscription-manager list --available

Attach the appropriate subscription to your system by entering a command as follows:

subscription-manager attach --pool=pool_id

To verify the list of subscriptions your system has currently attached, at any time, run:

subscription-manager list --consumed

MANAGING SOFTWARE REPOSITORIES

To verify that, use yum to list all enabled repositories:

 yum repolist
To list all available repositories, use the following command:
subscription-manager repos --list
rhel-version-variant-rpms
rhel-version-variant-debug-rpms
rhel-version-variant-source-rpms

To enable a repository, enter a command as follows:

 subscription-manager repos --enable repository

to disable a repository, use the following command:

subscription-manager repos --disable repository

Enter a command as follows to remove the selected subscription:

subscription-manager remove --serial=serial_number

To remove all subscriptions attached to the system, run the following command: /

subscription-manager remove --all

CHAPTER 8. ACCESSING SUPPORT USING THE RED HAT SUPPORT TOOL

INSTALLING THE RED HAT SUPPORT TOOL

~]# yum install redhat-support-tool

REGISTERING THE RED HAT SUPPORT TOOL USING THE COMMAND LINE

~]# redhat-support-tool config user username

Where username is the user name of the Red Hat Customer Portal account.

~]# redhat-support-tool config password
Please enter the password for username:

USING THE RED HAT SUPPORT TOOL IN INTERACTIVE SHELL MODE

To start the tool in interactive mode, enter the following command:
~]$ redhat-support-tool

CONFIGURING THE RED HAT SUPPORT TOOL

config --help
- config user
- config user my-rhn-username
- config --unset user

Registering the Red Hat Support Tool Using Interactive Mode

1.Start the tool by entering the following command: 
~]# redhat-support-tool
2. Enter your Red Hat Customer Portal user name:

Command (? for help): config user username
To save your user name to the global configuration file, add the -g option.

3. Enter your Red Hat Customer Portal password:

Command (? for help): config password
Please enter the password for username:

~/.redhat-support-tool/redhat-support-tool.conf

config setting -g value

In order to be able to save settings globally, using the -g, --global option, the Red Hat Support Tool must be run as root because normal users do not have the permissions required to write to /etc/redhat-support-tool.conf.

config setting -u value

PART III. INSTALLING AND MANAGING SOFTWARE

Command Palette

Configuring the System Locale

CONFIGURING AND INSPECTING NETWORK ACCESS: nmcli and nmutui

Managing Network Connections After the Installation Process Using :nmcli

Managing Networking in web console

Registering the System after the Installation

Registering a System to EUS Content

To access the Extended Update Support (EUS) content, register your system as follows:

Registering a System to E4S Content

INSTALLING SOFTWARE

Managing Basic Software Installation Tasks with Subscription Manager and Yum

Enabling or Disabling the Services

What SELinux Is and How It Enhances System Security

Ensuring the Required State of SELinux

Managing SELinux in web console

Secure Shell (SSH)

Disabling SSH Root Login

Most Basic Command-Line Tools to Manage User Accounts and Groups

Managing User Accounts in web console

Ensuring That kdump Is Installed and Enabled

ReaR Is and Which Tasks It Can Be Used For

Quickstart to Creation of the Rescue System with ReaR

USING THE LOG FILES TO TROUBLESHOOT PROBLEMS

CHAPTER 2. SYSTEM LOCALE AND KEYBOARD CONFIGURATION

Displaying the Current Status

Listing Available Locales

Setting the Locale

Changing the Default Locale

CHANGING THE KEYBOARD LAYOUT

CHAPTER 3. CONFIGURING THE DATE AND TIME

USING THE TIMEDATECTL COMMAND

USING THE DATE COMMAND

Changing the Current Time

USING THE HWCLOCK COMMAND

Synchronizing the Date and Time

Synchronizing the Hardware Clock with System Time

CHAPTER 4. MANAGING USERS AND GROUPS

Shadow Passwords

USING COMMAND-LINE TOOLS

Adding a New User

Adding a New Group

Setting Default Permissions for New Files Using umask

ADDITIONAL RESOURCES

CHAPTER 5. ACCESS CONTROL LISTS

Remove all permissions

Setting default ACLs For example,

Retrieving ACLs

ARCHIVING FILE SYSTEMS WITH ACLS

CHAPTER 6. GAINING PRIVILEGES

ADDITIONAL RESOURCES

REGISTERING THE SYSTEM AND MANAGING SUBSCRIPTIONS

CHAPTER 8. ACCESSING SUPPORT USING THE RED HAT SUPPORT TOOL

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