استفاده و مدیریت لینوکس: جلد دوم، از صفر تا مدیر سیستم: موضوعات پیشرفته (ویرایش دوم)

In Using and Administering Linux: Volume 3 you’ll work with multiple VMs on a single physical host to create a network in which to sharpen your sysadmin skills. Chapters have been fully updated to Fedora Linux 38 with expanded content and figures as well brand new material on the BTRFS file system, using Zram for swap, NetworkManager, automation with Ansible, as well as systemd. Focusing on network and other advanced services, this second edition of the final series volume builds upon the skills you have learned so far in volumes 1&2 and will depend upon the virtual network and VMs created there. Start by reviewing the administration of Linux servers and install and configure various Linux server services such as DHCP, DNS, NTP, and SSH server that will be used to provide advanced network services. You’ll then learn to install and configure servers such as BIND for name services, DHCP for network host configuration, and SSH for secure logins to remote hosts. Other topics covered include public/private keypairs to further enhance security, SendMail and IMAP and antispam protection for email, using Apache and WordPress to create and manage web sites, NFS, SAMBA, and Chrony. This volume also covers SELinux and its use in making your systems even more secure., You will learn to build RPMs to be used to distribute automation scripts. All of these services are installed on a single server host over the course of the book and by the time you are finished you will have a single server that provides these services for your network. What You Will Learn Install, configure, and manage several Linux server services such as email with spam management and single and multiple web sites Work with NTP time synchronization, DHCP, SSH, and file sharing with Unix/Linux and Windows clients Create RPMs for distribution of scripts and administrative programs. Understand and work with enhanced security. Who This Book Is For Those who are already Linux power users – SysAdmins who ... Table of Contents About the Author About the Technical Reviewers Acknowledgments Introduction Chapter 20: Logical Volume Management (LVM) Objectives The Need for Logical Volume Management Running Out of Disk Space in VirtualBox Recovery LVM Structure Extending a Logical Volume Creating and Extending Volume Groups Create a New Volume Group Extend an Existing Volume Group Tips Advanced Capabilities Chapter Summary Exercises Chapter 21: File Managers Objectives Introduction Text-Mode Interface Graphical Interface Default File Manager Text-Mode File Managers Midnight Commander Other Text-Mode File Managers Vifm nnn Graphical File Managers Krusader Thunar Dolphin XFE Other File Managers Chapter Summary Exercises Chapter 22: Everything Is a File Objectives What Is a File? Device Files Device File Creation udev Simplification Naming Rules Rule Change Blues Device Data Flow Device File Classification Fun with Device Files Randomness, Zero, and More Back Up the Master Boot Record Implications of Everything Is a File Chapter Summary Exercises Chapter 23: Managing Processes Objectives Processes Process Scheduling in the Kernel Tools top Summary Section Process Section More About Load Averages ... ...and Signals CPU Hogs Process Scheduling Nice Numbers Killing Processes Other Interactive Tools atop Summary Section Process Section Configuration htop Summary Section Process Section Configuration Glances Summary Section Process Section Sidebar Configuration Other Tools The Impact of Measurement Chapter Summary Exercises Chapter 24: Special Filesystems Objectives Introduction The /proc Filesystem The /sys Filesystem Storage-Based Swap Space Types of Linux Swap Thrashing What Is the Right Amount of Storage-Based Swap Space? Adding More Swap Space on a Non-LVM Disk Partition Adding Swap to an LVM Disk Environment Other Swap Options with LVM Using Zram for Swap Space But Why? How Much Swap? Managing Zram Swap Creating Zram Swap Augmenting Zram Swap Tuning Swap Swap Size Recommendations Removing Traditional Swap Partitions and Files Chapter Summary Exercises Chapter 25: Regular Expressions Objectives Introducing Regular Expressions Getting Started The Mailing List The First Solution The Second Solution grep Data Flow REGEX Building Blocks Repetition Other Metacharacters sed Other Tools That Implement Regular Expressions Resources Chapter Summary Exercises Chapter 26: Printing Objectives Introduction About Printers Print Languages Printers and Linux CUPS Creating the Print Queue Printing to a PDF File File Conversion Tools a2ps ps2pdf pr ps2ascii Operating System–Related Conversion Tools unix2dos dos2unix unix2mac and mac2unix Miscellaneous Tools lpmove wvText and odt2txt Chapter Summary Exercises Chapter 27: Hardware Detection Objectives Introduction dmidecode lshw lsusb usb-devices lspci Cleanup Chapter Summary Exercises Chapter 28: Command-Line Programming Objectives Introduction Definition of a Program Simple CLI Programs Some Basic Syntax Output to the Display Something About Variables Control Operators Return Codes The Operators Program Flow Control true and false Logical Operators Syntax File Operators String Comparison Operators Numeric Comparison Operators Miscellaneous Operators Grouping Program Statements Expansions Brace Expansion Tilde Expansion Pathname Expansion Command Substitution Arithmetic Expansion for Loops Other Loops while until Chapter Summary Exercises Chapter 29: Automation with Bash Scripts Objectives Introduction Why I Use Shell Scripts Shell Scripts Scripts vs. Compiled Programs Updates About Updates Create a List of Requirements The CLI Program Security Convert the CLI Program to a Script Add Some Logic Limit to Root Add Command-Line Options Check for Updates Is a Reboot Required? Adding a Help Function Finishing the Script About Testing Testing in Production Fuzzy Testing Testing the Script Licensing Automated Testing Additional Levels of Automation Cleanup Chapter Summary Exercises Chapter 30: Automation with Ansible Objectives My First Day with Ansible The Ansible Strategy My Problem Getting Started Installing Ansible Configuration ansible.cfg Preparing to Use Ansible Ansible Facts The hosts File Creating the hosts File Modules Introduction to Playbooks Output Files Multiple Playbook Runs How to Create an Ansible Playbook What Is a Playbook? Updates Redux Defining the Requirements Syntax Creating the Playbook Ansible for Many Systems The Second Play The Third Play Final Thoughts Resources Exercises Chapter 31: Time and Automation Objectives Introduction Keeping Time with Chrony The NTP Server Hierarchy NTP Choices Chrony Structure Client Configuration chronyc As an Interactive Tool Using cron for Timely Automation The cron Daemon (crond) crontab cron Examples crontab Entries Creating the crontab File Other Scheduling Options /etc/cron.hourly anacron Thoughts About cron Scheduling Tips Security cron Resources at Syntax Time Specifications Security Setting the Hardware Clock About Time Zones Cleanup Chapter Summary Exercises Chapter 32: Networking Objectives Introduction About IPv6 Basic Networking Concepts Definitions MAC Address IP Address IP Address Assignments TCP/IP The TCP/IP Network Model A Simple Example CIDR: Network Notation and Configuration Network Classes Along Came CIDR Variable Length Subnet Masking DHCP Client Configuration NIC Naming Conventions How It Works, Sort Of Interface Configuration Files: Old Style When Is an Interface Configuration File Needed? The Interface Configuration File The networks File The network File (Deprecated) The route- File Name Services How a Name Search Works Using the /etc/hosts File Introduction to Network Routing The Routing Table iptraf-ng Chapter Summary Exercises Chapter 33: NetworkManager Introduction Network Startup The NetworkManager Service What NetworkManager Replaces What NetworkManager Does Viewing Interface Configuration Fixing the Found Problems Activate and Deactivate Network Connections NetworkManager Keyfiles Why Should I Migrate My Files? Migration Experiments What If I Don’t Have ifcfg Files? Reverting to DHCP Creating New Keyfiles Text Editor Using nmtui Using nmcli Using the GUI NetworkManager Connection Editor How to Manage Wireless Networks Using the Command Line Chapter Summary Chapter 34: BtrFS Objectives Introduction BtrFS vs. EXT4 BtrFS Advantages BtrFS and EXT4 Similarities EXT4 Advantages Filesystem Structure with BtrFS How It Works Creating BtrFS Filesystems BtrFS RAID Structure Mounting BtrFS Filesystems Exploring the BtrFS Volume Notes on an Edge-Case BtrFS Failure Simplification What Is a Subvolume? Using BtrFS Subvolumes Converting from EXT to BtrFS Using BtrFS as Swap Cleanup OpenZFS: An Alternative Chapter Summary Chapter 35: Getting Started with systemd Objectives Introduction Learning to Love systemd Linux Boot Controversy Why I Prefer SystemV Why I Prefer systemd The Real Issue Previous Work The systemd Plan to Take Over the World More Data for the Admin systemd Standardizes Configuration Sometimes, the Pain systemd Tasks Architecture Linux Startup with systemd systemd as PID 1 Exploring Startup GRUB Targets About the Current Target Using systemd Units The systemd Suite Unit Files systemctl Service Units Mounts the Old Way Creating a Mount Unit Chapter Summary Exercises Chapter 36: Advanced systemd Functions Objectives systemd Calendar and Time Spans Definitions Absolute Timestamp Accuracy Calendar Event Time Span Calendar Event Expressions Exploring systemd Time Syntax Using systemd Journals The Journal The systemd Journal Service Configuration About That Binary Data Format... Using journalctl Journal Storage Usage Journal File Rotation Analyzing systemd Startup and Configuration Startup Overview Managing Startup with systemd Chapter Summary Exercises Chapter 37: systemd Finale Objectives Introduction Calendar Event Expression Review systemd Timers Creating a Timer Timer Types Home Directory Security with systemd-homed What Is It? Creating Controlled Users The homectl Command Limitations But I Don’t Want It! Resource Management with systemd Using cgroups for Process Management Exploring the cgroup Hierarchy Managing cgroups with systemd Chapter Summary Exercises Chapter 38: D-Bus and udev Objectives /dev Chaos About D-Bus About udev Naming Rules Making udev Work A Basic Script Refining the Rule into Something Useful Security udev in the Real World Chapter Summary Exercises Chapter 39: Using Traditional Logs Objectives About Traditional Logs logrotate Log File Content messages secure dmesg Following Log Files logwatch Chapter Summary Exercises Chapter 40: Managing Users Objectives Introduction The Root Account Your User Account Your Home Directory User Accounts and Groups The /etc/passwd File nologin Shells The /etc/shadow File The /etc/group File The /etc/login.defs File Account Configuration Files Password Security Password Encryption Generating Good Passwords Password Quality Managing User Accounts Creating New Accounts The useradd Command Creating New Accounts by Editing the Files Locking a User Account Deleting User Accounts Forcing Account Logoff Setting Resource Limits Chapter Summary Exercises Chapter 41: Managing the Firewall Objectives Introducing Firewalls Ports Firewall Rules Firewall Tools Block (Almost) Everything Crunchy on the Outside firewalld firewalld Zones Exploring the Firewall Adding a New Zone Zones in a Complex Environment Adding and Deleting Services Adding a Service for a Specific Period of Time Wireless Using --reload Zone Files Minimum Usable Firewall Configuration Panic Mode firewall-config GUI nftables Outbound Blocking Fail2ban Chapter Summary Exercises Index Learn to be a Linux sysadmin and an expert user of the Linux operating system, even with no previous Linux experience. This second edition of the popular and highly rated Linux self-study training course has been fully updated to Fedora Linux 37 with expanded and revised content and figures as well new chapters on the BTRFS file system, using Zram for swap, NetworkManager, automation with Ansible, and systemd. Like the previous version, this edition has been reviewed for technical accuracy by a highly respected Linux expert and will prepare you to manage complex systems with ease and equip you for a new career. It has also been reviewed by a student who took this course to ensure its readability and flow for those with little or no previous experience with Linux. This second volume builds upon what you learned in the first and depends upon the virtual network and virtual machine created there. You’ll see how to manage and monitor running processes, discover the power of the special filesystems, monitor and tune the kernel while it is running – without a reboot. You’ll then turn to regular expressions and the power that using them for pattern matching can bring to the command line, and learn to manage printers and printing from the command line and unlock the secrets of the hardware on which your Linux operating system is running. Experiment with command line programming and how to automate various administrative tasks, networking, and the many services that are required in a Linux system. Use the logs and journals to look for clues to problems and confirmation that things are working correctly, and learn to enhance the security of your Linux systems and how to perform easy local and remote backups. What You Will Learn: • Understand Logical Volume Management, using file managers, and special filesystems • Exploit everything is a file • Perform command line programming and basic automation • Configure printers and manage other hardware • Manage system services with systemd, user management, security, and local and remote backups using simple and freely available tools Who This Book Is For: Anyone who wants to continue to learn Linux in depth as an advanced user and system administrator at the command line while using the GUI desktop to leverage productivity.