Essential System Administration. Tools and Techniques for Linux and Unix Administration. 3rd Edition Aeleen Frisch

Spis treści książki

• Essential System Administration, 3rd Edition
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  • Preface
    • The Unix Universe
      • Unix Versions Discussed in This Book
    • Audience
    • Organization
      • Chapter Descriptions
    • Conventions Used in This Book
    • Comments and Questions
    • Acknowledgments
  • 1. Introduction to System Administration
    • 1.1. Thinking About System Administration
    • 1.2. Becoming Superuser
      • 1.2.1. Controlling Access to the Superuser Account
      • 1.2.2. Running a Single Command as root
      • 1.2.3. sudo: Selective Access to Superuser Commands
    • 1.3. Communicating with Users
      • 1.3.1. Sending a Message
      • 1.3.2. Sending a Message to All Users
      • 1.3.3. The Message of the Day
      • 1.3.4. Specifying the Pre-Login Message
    • 1.4. About Menus and GUIs
      • 1.4.1. Ups and Downs
      • 1.4.2. AIX: SMIT and WSM
      • 1.4.3. HP-UX: SAM
      • 1.4.4. Solaris: admintool and Sun Management Console
      • 1.4.5. Linux: Linuxconf
      • 1.4.6. Red Hat Linux: redhat-config-*
      • 1.4.7. SuSE Linux: YaST2
      • 1.4.8. FreeBSD: sysinstall
      • 1.4.9. Tru64: SysMan
      • 1.4.10. Other Freely Available Administration Tools
        • 1.4.10.1. The Ximian Setup Tools
      • 1.4.11. VNC
    • 1.5. Where Does the Time Go?
  • 2. The Unix Way
    • 2.1. Files
      • 2.1.1. File Ownership
        • 2.1.1.1. Displaying file ownership
        • 2.1.1.2. Who owns new files?
        • 2.1.1.3. Changing file ownership
      • 2.1.2. File Protection
        • 2.1.2.1. Types of file and directory access
        • 2.1.2.2. Access classes
        • 2.1.2.3. Setting file protection
        • 2.1.2.4. Beyond the basics
        • 2.1.2.5. Specifying numeric file modes
        • 2.1.2.6. Specifying the default file mode
        • 2.1.2.7. Special-purpose access modes
        • 2.1.2.8. Save-text access on directories
        • 2.1.2.9. Setgid access on directories
        • 2.1.2.10. Numerical equivalents for special access modes
      • 2.1.3. How to Recognize a File Access Problem
      • 2.1.4. Mapping Files to Disks
        • 2.1.4.1. Regular files
        • 2.1.4.2. Directories
        • 2.1.4.3. Special files: character and block device files
        • 2.1.4.4. Links
          • 2.1.4.4.1. Tru64 Context-Dependent Symbolic Links
        • 2.1.4.5. Sockets
        • 2.1.4.6. Named pipes
        • 2.1.4.7. Using ls to identify file types
    • 2.2. Processes
      • 2.2.1. Interactive Processes
      • 2.2.2. Batch Processes
      • 2.2.3. Daemons
      • 2.2.4. Process Attributes
        • 2.2.4.1. The life cycle of a process
        • 2.2.4.2. Setuid and setgid file access and process execution
        • 2.2.4.3. The relationship between commands and files
    • 2.3. Devices
      • 2.3.1. An In-Depth Device Example: Disks
        • 2.3.1.1. Fixed-disk special files
      • 2.3.2. Special Files for Other Devices
        • 2.3.2.1. Commands for listing the devices on a system
        • 2.3.2.2. The AIX Object Data Manager
      • 2.3.3. The Unix Filesystem Layout
      • 2.3.4. The Root Directory
      • 2.3.5. The /usr Directory
      • 2.3.6. The /var Directory
  • 3. Essential AdministrativeTools and Techniques
    • 3.1. Getting the Most from Common Commands
      • 3.1.1. Getting Help
        • 3.1.1.1. Changing the search order
        • 3.1.1.2. Setting up man -k
      • 3.1.2. Piping into grep and awk
      • 3.1.3. Finding Files
      • 3.1.4. Repeating Commands
      • 3.1.5. Creating Several Directory Levels at Once
      • 3.1.6. Duplicating an Entire Directory Tree
      • 3.1.7. Comparing Directories
      • 3.1.8. Deleting Pesky Files
      • 3.1.9. Putting a Command in a Cage
      • 3.1.10. Starting at the End
      • 3.1.11. Be Creative
    • 3.2. Essential Administrative Techniques
      • 3.2.1. Periodic Program Execution: The cron Facility
        • 3.2.1.1. crontab files
          • 3.2.1.1.1. FreeBSD and Linux crontab entry format enhancements
        • 3.2.1.2. Adding crontab entries
        • 3.2.1.3. cron log files
        • 3.2.1.4. Using cron to automate system administration
          • 3.2.1.4.1. FreeBSD: The periodic command
          • 3.2.1.4.2. Linux: The /etc/cron.* directories
        • 3.2.1.5. cron security issues
      • 3.2.2. System Messages
        • 3.2.2.1. The syslog facility
        • 3.2.2.2. Configuring syslog
        • 3.2.2.3. Enhancements to syslog.conf
          • 3.2.2.3.1. AIX
          • 3.2.2.3.2. FreeBSD and Linux
          • 3.2.2.3.3. Solaris
          • 3.2.2.3.4. The Tru64 syslog log file hierarchy
        • 3.2.2.4. The logger utility
      • 3.2.3. Hardware Error Messages
        • 3.2.3.1. The AIX error log
          • 3.2.3.1.1. Viewing errors under HP-UX
          • 3.2.3.1.2. The Tru64 binary error logger
      • 3.2.4. Administering Log Files
        • 3.2.4.1. Managing log file disk requirements
        • 3.2.4.2. Monitoring log file contents
      • 3.2.5. Managing Software Packages
        • 3.2.5.1. HP-UX: Bundles, products, and subproducts
        • 3.2.5.2. AIX: Apply versus commit
        • 3.2.5.3. FreeBSD ports
      • 3.2.6. Building Software Packages from Source Code
        • 3.2.6.1. mtools: Using configure and accepting imperfections
        • 3.2.6.2. bzip2: Converting Linux-based make procedures
        • 3.2.6.3. jove: Configuration via make file settings
        • 3.2.6.4. Internet software archives
  • 4. Startup and Shutdown
    • 4.1. About the Unix Boot Process
      • 4.1.1. From Power On to Loading the Kernel
      • 4.1.2. Booting to Multiuser Mode
      • 4.1.3. Booting to Single-User Mode
        • 4.1.3.1. Password protection for single-user mode
        • 4.1.3.2. Firmware passwords
      • 4.1.4. Starting a Manual Boot
        • 4.1.4.1. AIX
        • 4.1.4.2. FreeBSD
        • 4.1.4.3. HP-UX
        • 4.1.4.4. Linux
        • 4.1.4.5. Tru64
        • 4.1.4.6. Solaris
        • 4.1.4.7. Booting from alternate media
      • 4.1.5. Boot Activities in Detail
        • 4.1.5.1. Boot messages
        • 4.1.5.2. Saved boot log files
        • 4.1.5.3. General considerations
        • 4.1.5.4. Preliminaries
        • 4.1.5.5. Preparing filesystems
        • 4.1.5.6. Checking and mounting the root filesystem
        • 4.1.5.7. Preparing other local filesystems
        • 4.1.5.8. Saving a crash dump
        • 4.1.5.9. Starting paging
        • 4.1.5.10. Security-related activities
        • 4.1.5.11. Checking disk quotas
        • 4.1.5.12. Starting servers and initializing local subsystems
          • 4.1.5.12.1. The AIX System Resource Controller
        • 4.1.5.13. Connecting to the network
        • 4.1.5.14. Housekeeping activities
        • 4.1.5.15. Allowing users onto the system
    • 4.2. Initialization Files and Boot Scripts
      • 4.2.1. Initialization Files Under FreeBSD
      • 4.2.2. Initialization Files on System V Systems
        • 4.2.2.1. System V run levels
        • 4.2.2.2. Using the telinit command to change run levels
        • 4.2.2.3. Initialization files overview
        • 4.2.2.4. The init configuration file
        • 4.2.2.5. The rcn initialization scripts
        • 4.2.2.6. Boot script configuration files
        • 4.2.2.7. File location summary
        • 4.2.2.8. Solaris initialization scripts
        • 4.2.2.9. Tru64 initialization scripts
        • 4.2.2.10. Linux initialization scripts
        • 4.2.2.11. AIX: Making System V work like BSD
      • 4.2.3. Customizing the Boot Process
        • 4.2.3.1. Adding to the boot scripts
        • 4.2.3.2. Eliminating certain boot-time activities
        • 4.2.3.3. Modifying standard scripts
        • 4.2.3.4. Guidelines for writing initialization scripts
    • 4.3. Shutting Down a Unix System
      • 4.3.1. The System V shutdown Command
        • 4.3.1.1. HP-UX shutdown security
      • 4.3.2. The BSD-Style shutdown Command
      • 4.3.3. The Linux shutdown Command
      • 4.3.4. Ensuring Disk Accuracy with the sync Command
      • 4.3.5. Aborting a Shutdown
    • 4.4. Troubleshooting: Handling Crashes and Boot Failures
      • 4.4.1. Power-Failure Scripts
      • 4.4.2. When the System Wont Boot
        • 4.4.2.1. Bad or flaky hardware
        • 4.4.2.2. Unreadable filesystems on working disks
        • 4.4.2.3. Damage to non-filesystem areas of a disk
        • 4.4.2.4. Incompatible hardware
        • 4.4.2.5. System configuration errors
  • 5. TCP/IP Networking
    • 5.1. Understanding TCP/IP Networking
      • 5.1.1. Media and Topologies
        • 5.1.1.1. Identifying network adapters
      • 5.1.2. Protocols and Layers
      • 5.1.3. Ports, Services, and Daemons
      • 5.1.4. Administrative Commands
      • 5.1.5. A Sample TCP/IP Conversation
      • 5.1.6. Names and Addresses
      • 5.1.7. Subnets and Supernets
        • 5.1.7.1. Introducing IPv6 host addresses
      • 5.1.8. Connecting Network Segments
    • 5.2. Adding a New Network Host
      • 5.2.1. Configuring the Network Interface with ifconfig
        • 5.2.1.1. Ethernet interface names
        • 5.2.1.2. Other uses of ifconfig
        • 5.2.1.3. ifconfig on Solaris systems
        • 5.2.1.4. Interface configuration at boot time
      • 5.2.2. Dynamic IP Address Assignment with DHCP
        • 5.2.2.1. AIX
        • 5.2.2.2. FreeBSD
        • 5.2.2.3. HP-UX
        • 5.2.2.4. Linux
        • 5.2.2.5. Solaris
        • 5.2.2.6. Tru64
      • 5.2.3. Name Resolution Options
        • 5.2.3.1. The /etc/hosts file
        • 5.2.3.2. Configuring a DNS client
        • 5.2.3.3. The name service switch file
      • 5.2.4. Routing Options
        • 5.2.4.1. AIX
        • 5.2.4.2. FreeBSD
        • 5.2.4.3. HP-UX
        • 5.2.4.4. Linux
        • 5.2.4.5. Solaris
        • 5.2.4.6. Tru64
    • 5.3. Network Testing and Troubleshooting
  • 6. Managing Users and Groups
    • 6.1. Unix Users and Groups
      • 6.1.1. The Password File, /etc/passwd
      • 6.1.2. The Shadow Password File, /etc/shadow
        • 6.1.2.1. The FreeBSD /etc/ master.passwd file
        • 6.1.2.2. The protected password database under HP-UX and Tru64
      • 6.1.3. The Group File, /etc/group
        • 6.1.3.1. User-private groups
      • 6.1.4. Dynamic Group Memberships
        • 6.1.4.1. The Linux group shadow file, /etc/gshadow
        • 6.1.4.2. The HP-UX /etc/logingroup file
        • 6.1.4.3. AIX group sets
      • 6.1.5. User Account Database File Protections
      • 6.1.6. Standard Unix Users and Groups
      • 6.1.7. Using Groups Effectively
    • 6.2. Managing User Accounts
      • 6.2.1. Adding a New User Account
      • 6.2.2. Defining a New User Account
      • 6.2.3. Assigning a Shell
        • 6.2.3.1. Captive accounts
      • 6.2.4. Assigning a Password
      • 6.2.5. Creating a Home Directory
      • 6.2.6. User Environment Initialization Files
        • 6.2.6.1. Sample login initialization files
        • 6.2.6.2. Sample shell initialization files
        • 6.2.6.3. The AIX /etc/security/environ file
        • 6.2.6.4. Desktop environment initialization files
        • 6.2.6.5. Systemwide initialization files
      • 6.2.7. Setting File Ownership
      • 6.2.8. Adding the User to Other System Facilities
      • 6.2.9. Specifying Other User Account Controls
        • 6.2.9.1. AIX user account controls
        • 6.2.9.2. FreeBSD user account controls
        • 6.2.9.3. Linux user account controls
        • 6.2.9.4. Solaris login process settings
        • 6.2.9.5. Specifying login time restrictions under HP-UX and Tru64
      • 6.2.10. Testing the New Account
        • 6.2.10.1. Using su to re-create a user's environment
      • 6.2.11. Disabling and Removing User Accounts
        • 6.2.11.1. Removing a user account
    • 6.3. Administrative Tools for Managing User Accounts
      • 6.3.1. Command-Line Utilities
        • 6.3.1.1. The useradd command: HP-UX, Linux, Solaris, and Tru64
          • 6.3.1.1.1. Setting useradd's defaults
          • 6.3.1.1.2. Modifying accounts with usermod
          • 6.3.1.1.3. Removing accounts with userdel
        • 6.3.1.2. Commands for managing groups
        • 6.3.1.3. The Linux gpasswd command
        • 6.3.1.4. The FreeBSD user account utilities
        • 6.3.1.5. The AIX user account utilities
          • 6.3.1.5.1. Removing user accounts
          • 6.3.1.5.2. Utilities for managing groups
      • 6.3.2. Graphical User Account Managers
        • 6.3.2.1. Managing users with SMIT under AIX
        • 6.3.2.2. Managing users with SAM under HP-UX
          • 6.3.2.2.1. HP-UX account and file exclusion
        • 6.3.2.3. Linux graphical user managers
          • 6.3.2.3.1. Managing users with Linuxconf
          • 6.3.2.3.2. The KDE User Manager
          • 6.3.2.3.3. The Red Hat User Manager
        • 6.3.2.4. Solaris GUI tools for managing user accounts
        • 6.3.2.5. Managing user accounts with dxaccounts under Tru64
      • 6.3.3. Automation You Have to Do Yourself
    • 6.4. Administering User Passwords
      • 6.4.1. Selecting Effective Passwords
        • 6.4.1.1. Forcing a password change
        • 6.4.1.2. Managing dozens of passwords
      • 6.4.2. Educating Users About Selecting Effective Passwords
        • 6.4.2.1. Password advice in the age of the Internet
      • 6.4.3. Setting Password Restrictions
        • 6.4.3.1. Password aging
        • 6.4.3.2. Password triviality checks
          • 6.4.3.2.1. Tru64
          • 6.4.3.2.2. AIX
          • 6.4.3.2.3. Linux
          • 6.4.3.2.4. FreeBSD
        • 6.4.3.3. The freely available npasswd command
        • 6.4.3.4. Password history lists
        • 6.4.3.5. Password settings default values
      • 6.4.4. Testing User Passwords for Weaknesses
        • 6.4.4.1. John the Ripper
        • 6.4.4.2. Using Crack to find poorly chosen passwords
        • 6.4.4.3. How well do they do?
    • 6.5. User Authentication with PAM
      • 6.5.1. PAM Defaults
      • 6.5.2. PAM Modules Under Linux
        • 6.5.2.1. Checking passwords at selection time
        • 6.5.2.2. Specifying allowed times and locations for system access
        • 6.5.2.3. MD5 passwords
      • 6.5.3. PAM Modules Provided by Other Unix Systems
      • 6.5.4. More Complex PAM Configuration
    • 6.6. LDAP: Using a Directory Service for User Authentication
      • 6.6.1. About LDAP
      • 6.6.2. LDAP Directories
        • 6.6.2.1. About schemas
      • 6.6.3. Installing and Configuring OpenLDAP: An Overview
        • 6.6.3.1. More about LDAP searching
      • 6.6.4. Using OpenLDAP for User Authentication
        • 6.6.4.1. Select an appropriate schema
        • 6.6.4.2. Convert existing user account data
        • 6.6.4.3. Specify the name service search order
          • 6.6.4.3.1. Configure PAM to use OpenLDAP
        • 6.6.4.4. Configure directory access control
        • 6.6.4.5. OpenLDAP access control
      • 6.6.5. Securing OpenLDAP Authentication
      • 6.6.6. Wither NIS?
  • 7. Security
    • 7.1. Prelude: What's Wrong with This Picture?
    • 7.2. Thinking About Security
      • 7.2.1. Security Policies and Plans
        • 7.2.1.1. Security policies
        • 7.2.1.2. Security plans
      • 7.2.2. Unix Lines of Defense
        • 7.2.2.1. Physical security
        • 7.2.2.2. Firewalls and network filters
        • 7.2.2.3. Passwords
        • 7.2.2.4. Encrypting data
        • 7.2.2.5. Backups
      • 7.2.3. Version-Specific Security Facilities
    • 7.3. User Authentication Revisited
      • 7.3.1. Smart Cards
      • 7.3.2. One-Time Passwords
      • 7.3.3. Solaris and HP-UX Dialup Passwords
      • 7.3.4. AIX Secondary Authentication Programs
      • 7.3.5. Better Network Authentication: Kerberos
    • 7.4. Protecting Files and the Filesystem
      • 7.4.1. Search Path Issues
      • 7.4.2. Small Mistakes Compound into Large Holes
      • 7.4.3. The setuid and setgid Access Modes
        • 7.4.3.1. Writing setuid/setgid programs
      • 7.4.4. Access Control Lists
        • 7.4.4.1. Introducing access control lists
        • 7.4.4.2. Manipulating AIX ACLs
        • 7.4.4.3. HP-UX ACLs
        • 7.4.4.4. POSIX access control lists: Linux, Solaris, and Tru64
      • 7.4.5. Encryption
        • 7.4.5.1. The crypt command
        • 7.4.5.2. Public key encryption: PGP and GnuPG
        • 7.4.5.3. Selecting passphrases
    • 7.5. Role-Based Access Control
      • 7.5.1. AIX Roles
      • 7.5.2. Solaris Role-Based Access Control
    • 7.6. Network Security
      • 7.6.1. Establishing Trust
        • 7.6.1.1. The implications of trust
      • 7.6.2. The Secure Shell
      • 7.6.3. Securing Network Daemons
        • 7.6.3.1. TCP Wrappers: Better inetd access control and logging
        • 7.6.3.2. xinetd
        • 7.6.3.3. Disable what you don't need
      • 7.6.4. Port Scanning
      • 7.6.5. Defending the Border: Firewalls and Packet Filtering
    • 7.7. Hardening Unix Systems
      • 7.7.1. Plan Before Acting
      • 7.7.2. Secure the Physical System
      • 7.7.3. Install the Operating System
      • 7.7.4. Secure Local Filesystems
      • 7.7.5. Securing Services
      • 7.7.6. Restrict root Access
      • 7.7.7. Configure User Authentication and Account Defaults
      • 7.7.8. Set up Remote Authentication
      • 7.7.9. Install and Configure Ongoing Monitoring
      • 7.7.10. Backup
      • 7.7.11. Other Activities
    • 7.8. Detecting Problems
      • 7.8.1. Password File Issues
      • 7.8.2. Monitoring the Filesystem
        • 7.8.2.1. Checking file ownership and protection
        • 7.8.2.2. Looking for setuid and setgid files
        • 7.8.2.3. Checking modification dates and inode numbers
        • 7.8.2.4. Computing checksums
        • 7.8.2.5. Run fsck occasionally
      • 7.8.3. Automating Security Monitoring
        • 7.8.3.1. Trusted computing base checking
        • 7.8.3.2. System integrity checking with Tripwire
        • 7.8.3.3. Vulnerability scanning
          • 7.8.3.3.1. General system security monitoring via COPS
        • 7.8.3.4. Scanning for network vulnerabilities
      • 7.8.4. What to Do if You Find a Problem
      • 7.8.5. Investigating System Activity
        • 7.8.5.1. Monitoring unsuccessful login attempts
        • 7.8.5.2. su log files
        • 7.8.5.3. History on the root account
        • 7.8.5.4. Tracking user activities
        • 7.8.5.5. Event-auditing systems
      • 7.8.6. Intruders Can Read
  • 8. Managing Network Services
    • 8.1. Managing DNS Servers
      • 8.1.1. Zones
      • 8.1.2. Name Server Types
      • 8.1.3. About BIND
      • 8.1.4. Configuring named
        • 8.1.4.1. The master configuration file: named.conf
        • 8.1.4.2. The root hints file
        • 8.1.4.3. Zone files
          • 8.1.4.3.1. Reverse zone files and PTR records
          • 8.1.4.3.2. IPv6 zone file resource records
        • 8.1.4.4. Common mistakes to avoid
        • 8.1.4.5. Using subdomains
          • 8.1.4.5.1. Reverse zone files with arbitrary subnetting
        • 8.1.4.6. Forwarders
        • 8.1.4.7. Slave name server notifications
        • 8.1.4.8. Dynamic updates
        • 8.1.4.9. Incremental zone transfers
        • 8.1.4.10. Access control
        • 8.1.4.11. Securing DNS communications
          • 8.1.4.11.1. BIND 9 security futures
        • 8.1.4.12. BIND 9 views
        • 8.1.4.13. Securing the named process
        • 8.1.4.14. Configuring logging
      • 8.1.5. Name Server Maintenance and Troubleshooting
        • 8.1.5.1. Controlling the named server process
        • 8.1.5.2. Using the nslookup and dig utilities
    • 8.2. Routing Daemons
      • 8.2.1. Routing Concepts and Protocols
        • 8.2.1.1. Configuring routed
        • 8.2.1.2. Configuring gated
          • 8.2.1.2.1. Vendor specifics
    • 8.3. Configuring a DHCP Server
      • 8.3.1. AIX
      • 8.3.2. ISC DHCP: FreeBSD and Linux
      • 8.3.3. HP-UX
      • 8.3.4. Solaris
      • 8.3.5. Tru64
    • 8.4. Time Synchronization with NTP
      • 8.4.1. How NTP Works
      • 8.4.2. Setting Up NTP
        • 8.4.2.1. Enabling ntpd under FreeBSD
      • 8.4.3. A Simple Authentic Time Option
    • 8.5. Managing Network Daemons under AIX
    • 8.6. Monitoring the Network
      • 8.6.1. Standard Networking Utilities
      • 8.6.2. Packet Sniffers
        • 8.6.2.1. The Solaris snoop command
        • 8.6.2.2. Packet collecting under AIX and HP-UX
      • 8.6.3. The Simple Network Management Protocol
        • 8.6.3.1. SNMP concepts and constructs
        • 8.6.3.2. SNMP implementations
        • 8.6.3.3. Net-SNMP client utilities
          • 8.6.3.3.1. Generating traps
          • 8.6.3.3.2. AIX and Tru64 clients
        • 8.6.3.4. Configuring SNMP agents
          • 8.6.3.4.1. Net-SNMP snmpd daemon (FreeBSD and Linux)
          • 8.6.3.4.2. Net-SNMP access control
          • 8.6.3.4.3. The Net-SNMP trap daemon
          • 8.6.3.4.4. Configuring SNMP nder HP-UX
          • 8.6.3.4.5. Configuring SNMP under Solaris
          • 8.6.3.4.6. The AIX snmpd daemon
          • 8.6.3.4.7. The Tru64 snmpd daemon
        • 8.6.3.5. SNMP and security
      • 8.6.4. Network Management Packages
        • 8.6.4.1. Proactive network monitoring
          • 8.6.4.1.1. NetSaint
        • 8.6.4.2. Identifying trends over time
          • 8.6.4.2.1. MRTG and RRDtool
          • 8.6.4.2.2. Using Cricket to feed RRDtool
  • 9. Electronic Mail
    • 9.1. About Electronic Mail
      • 9.1.1. Mail Addressing and Delivery
        • 9.1.1.1. DNS MX records
        • 9.1.1.2. Mail aliases
        • 9.1.1.3. Mail forwarding
        • 9.1.1.4. Putting it all together
      • 9.1.2. Electronic Mail Policies
    • 9.2. Configuring User Mail Programs
      • 9.2.1. Automated Email Message Encryption
    • 9.3. Configuring Access Agents
      • 9.3.1. Setting Up User Agents to Use POP and IMAP
    • 9.4. Configuring the Transport Agent
      • 9.4.1. sendmail
        • 9.4.1.1. Configuring sendmail
        • 9.4.1.2. Getting started: A sample mail client configuration
        • 9.4.1.3. Building sendmail.cf
        • 9.4.1.4. Configuring the mail hub
        • 9.4.1.5. Selecting mailers
          • 9.4.1.5.1. More about pipes to files and programs
        • 9.4.1.6. Some client and mail hub variations
          • 9.4.1.6.1. An isolated internal network
          • 9.4.1.6.2. A null client
          • 9.4.1.6.3. Mailer-specific and other local relays
        • 9.4.1.7. More addressing options
          • 9.4.1.7.1. Sender aliasing
          • 9.4.1.7.2. Using LDAP for incoming mail addresses
          • 9.4.1.7.3. The redirect feature
        • 9.4.1.8. Virtual hosting
        • 9.4.1.9. The services switch file
        • 9.4.1.10. Spam suppression
          • 9.4.1.10.1. Message relaying
        • 9.4.1.11. Public blacklists and the access database
        • 9.4.1.12. sendmail security
          • 9.4.1.12.1. The sendmail default user
          • 9.4.1.12.2. Privacy options
          • 9.4.1.12.3. SASL authentication
          • 9.4.1.12.4. Reducing the sendmail daemon's privileges
        • 9.4.1.13. Monitoring ongoing operation
        • 9.4.1.14. Performance
        • 9.4.1.15. Debugging techniques
        • 9.4.1.16. Macro summary
      • 9.4.2. Postfix
        • 9.4.2.1. Installing Postfix
        • 9.4.2.2. Configuring Postfix
          • 9.4.2.2.1. Notifying the daemon
          • 9.4.2.2.2. Client systems
          • 9.4.2.2.3. The mail hub
          • 9.4.2.2.4. The local delivery agent
          • 9.4.2.2.5. Systems with intermittent Internet connections
          • 9.4.2.2.6. Address transformations
          • 9.4.2.2.7. Virtual domains
          • 9.4.2.2.8. LDAP lookups
        • 9.4.2.3. Access control and spam suppression
        • 9.4.2.4. Postfix security
        • 9.4.2.5. Monitoring and performance
        • 9.4.2.6. Debugging
    • 9.5. Retrieving Mail Messages
    • 9.6. Mail Filtering with procmail
      • 9.6.1. Configuring procmail
        • 9.6.1.1. Other procmail disposition options
        • 9.6.1.2. Using procmail to discard spam
        • 9.6.1.3. Using procmail for security scanning
        • 9.6.1.4. Debugging procmail
        • 9.6.1.5. Additional information
    • 9.7. A Few Final Tools
  • 10. Filesystems and Disks
    • 10.1. Filesystem Types
      • 10.1.1. About Unix Filesystems: Moments from History
        • 10.1.1.1. Journaled filesystems
        • 10.1.1.2. BSD soft updates
      • 10.1.2. Default Local Filesystems
    • 10.2. Managing Filesystems
      • 10.2.1. Mounting and Dismounting Filesystems
      • 10.2.2. Disk Special File Naming Conventions
      • 10.2.3. The mount and umount Commands
      • 10.2.4. Figuring Out Who's Using a File
      • 10.2.5. The Filesystem Configuration File
        • 10.2.5.1. Solaris: /etc/vfstab
        • 10.2.5.2. AIX: /etc/filesystems and /etc/swapspaces
      • 10.2.6. Automatic Filesystem Mounting
      • 10.2.7. Using fsck to Validate a Filesystem
        • 10.2.7.1. After fsck
    • 10.3. From Disks to Filesystems
      • 10.3.1. Defining Disk Partitions
      • 10.3.2. Adding Disks
        • 10.3.2.1. Preparing and connecting the disk
        • 10.3.2.2. Making special files
        • 10.3.2.3. FreeBSD
        • 10.3.2.4. Linux
          • 10.3.2.4.1. The Reiser filesystem
        • 10.3.2.5. Solaris
        • 10.3.2.6. AIX, HP-UX, and Tru64
        • 10.3.2.7. Remaking an existing filesystem
      • 10.3.3. Logical Volume Managers
        • 10.3.3.1. Disks, volume groups, and logical volumes
        • 10.3.3.2. Disk striping
        • 10.3.3.3. Disk mirroring and RAID
        • 10.3.3.4. AIX
          • 10.3.3.4.1. Replacing a failed disk
          • 10.3.3.4.2. Getting information from the LVM
          • 10.3.3.4.3. Disk striping and disk mirroring
        • 10.3.3.5. HP-UX
          • 10.3.3.5.1. Displaying LVM information
          • 10.3.3.5.2. Disk striping and mirroring
        • 10.3.3.6. Tru64
          • 10.3.3.6.1. AdvFS
          • 10.3.3.6.2. LSM
        • 10.3.3.7. Solaris
        • 10.3.3.8. Linux
        • 10.3.3.9. FreeBSD
      • 10.3.4. Floppy Disks
        • 10.3.4.1. Floppy disk special files
        • 10.3.4.2. Using DOS disks on Unix systems
        • 10.3.4.3. The Mtools utilities
        • 10.3.4.4. Stupid DOS partition tricks
      • 10.3.5. CD-ROM Devices
        • 10.3.5.1. CD-ROM drives under AIX
        • 10.3.5.2. The Solaris media-handling daemon
    • 10.4. Sharing Filesystems
      • 10.4.1. NFS
        • 10.4.1.1. Mounting remote directories
        • 10.4.1.2. Exporting local filesystems
          • 10.4.1.2.1. Exporting directories under Linux
          • 10.4.1.2.2. Exporting filesystems under Solaris
      • 10.4.2. The NFS Automounter
      • 10.4.3. Samba
        • 10.4.3.1. Samba authentication
          • 10.4.3.1.1. Mounting Windows filesystems under Linux and FreeBSD
  • 11. Backup and Restore
    • 11.1. Planning for Disasters and Everyday Needs
      • 11.1.1. Backup Capacity Planning
      • 11.1.2. Backup Strategies
        • 11.1.2.1. Unattended backups
        • 11.1.2.2. Data verification
        • 11.1.2.3. Storing backup media
        • 11.1.2.4. Off-site and long-term storage
    • 11.2. Backup Media
      • 11.2.1. Magnetic tape
      • 11.2.2. Magneto-optical disks
      • 11.2.3. CDs and DVDs
      • 11.2.4. Removable disks: Zip and Jaz
      • 11.2.5. Floppy disks
      • 11.2.6. Hard disks
      • 11.2.7. Stackers, jukeboxes, and similar devices
      • 11.2.8. Media Lifetime
      • 11.2.9. Comparing Backup Media
      • 11.2.10. Tape Special Files
        • 11.2.10.1. AIX tape device attributes
    • 11.3. Backing Up Files and Filesystems
      • 11.3.1. When tar or cpio Is Enough
        • 11.3.1.1. The tar command
          • 11.3.1.1.1. Solaris enhancements to the tar command
          • 11.3.1.1.2. The GNU tar utility: Linux and FreeBSD
        • 11.3.1.2. The cpio command
        • 11.3.1.3. Incremental backups with tar and cpio
        • 11.3.1.4. pax: Detente between tar and cpio
      • 11.3.2. Backing Up Individual Filesystems with dump
        • 11.3.2.1. The HP-UX fbackup utility
      • 11.3.3. Related Tape Utilities
        • 11.3.3.1. Data copying and conversion with dd
        • 11.3.3.2. Tape manipulation with mt
    • 11.4. Restoring Files from Backups
      • 11.4.1. Restores from tar and cpio Archives
      • 11.4.2. Restoring from dump Archives
        • 11.4.2.1. The restore utility's interactive mode
        • 11.4.2.2. The HP-UX frecover utility
      • 11.4.3. Moving Data Between Systems
    • 11.5. Making Table of Contents Files
    • 11.6. Network Backup Systems
      • 11.6.1. Remote Backups and Restores
      • 11.6.2. The Amanda Facility
        • 11.6.2.1. About Amanda
        • 11.6.2.2. How Amanda works
        • 11.6.2.3. Doing the math
        • 11.6.2.4. Configuring Amanda
          • 11.6.2.4.1. Setting up an Amanda client
          • 11.6.2.4.2. Selecting an Amanda server
          • 11.6.2.4.3. Setting up the Amanda server
        • 11.6.2.5. Amanda reports and logs
        • 11.6.2.6. Restoring files from an Amanda backup
      • 11.6.3. Commercial Backup Packages
    • 11.7. Backing Up and Restoring the System Filesystems
      • 11.7.1. AIX: mksysb and savevg
        • 11.7.1.1. Restoring individual files from a mksysb tape
        • 11.7.1.2. Saving and restoring AIX user volume groups
      • 11.7.2. FreeBSD
      • 11.7.3. HP-UX: make_recovery
      • 11.7.4. Linux
      • 11.7.5. Solaris
      • 11.7.6. Tru64: btcreate
  • 12. Serial Lines and Devices
    • 12.1. About Serial Lines
      • 12.1.1. Device Files for Serial Lines
      • 12.1.2. The tty Command
    • 12.2. Specifying Terminal Characteristics
      • 12.2.1. termcap and terminfo
        • 12.2.1.1. termcap entries
        • 12.2.1.2. terminfo entries
        • 12.2.1.3. Modifying entries
      • 12.2.2. The tset Command
      • 12.2.3. The stty Command
    • 12.3. Adding a New Serial Device
      • 12.3.1. Making the Physical Connection
        • 12.3.1.1. Hardware handshaking and flow control
      • 12.3.2. Terminal Line Configuration
        • 12.3.2.1. FreeBSD configuration files
          • 12.3.2.1.1. Secure terminal lines
          • 12.3.2.1.2. The /etc/gettytab file
        • 12.3.2.2. System V configuration files
          • 12.3.2.2.1. The /etc/gettydefs file
          • 12.3.2.2.2. Setting terminal line types under HP-UX
          • 12.3.2.2.3. The Linux mgetty configuration files
          • 12.3.2.2.4. Configuring terminal lines under AIX
      • 12.3.3. Starting the Terminal Line
      • 12.3.4. Terminal Handling Under Solaris
        • 12.3.4.1. Structure of the Service Access Facility
        • 12.3.4.2. Port monitors
        • 12.3.4.3. Creating port monitors with pmadm
        • 12.3.4.4. The ttydefs file
        • 12.3.4.5. Using admintool to configure serial lines
    • 12.4. Troubleshooting Terminal Problems
    • 12.5. Controlling Access to Serial Lines
    • 12.6. HP-UX and Tru64 Terminal Line Attributes
    • 12.7. The HylaFAX Fax Service
      • 12.7.1. Sending Faxes
      • 12.7.2. Managing Faxes
      • 12.7.3. HylaFAX Configuration Files
      • 12.7.4. Controlling Access to HylaFAX
    • 12.8. USB Devices
      • 12.8.1. FreeBSD USB Support
      • 12.8.2. Linux USB Support
      • 12.8.3. Solaris USB Support
  • 13. Printers and the Spooling Subsystem
    • 13.1. The BSD Spooling Facility
      • 13.1.1. User Commands
      • 13.1.2. Manipulating Print Jobs
      • 13.1.3. Managing Queues
      • 13.1.4. The Spooling Daemon
      • 13.1.5. Configuring Queues: The printcap File
        • 13.1.5.1. Spooling directories
        • 13.1.5.2. Restricting printer access
        • 13.1.5.3. A filter program
      • 13.1.6. Remote Printing
      • 13.1.7. Adding a New Printer
      • 13.1.8. LPD Variations
        • 13.1.8.1. FreeBSD
        • 13.1.8.2. Tru64
        • 13.1.8.3. Linux
    • 13.2. System V Printing
      • 13.2.1. User Commands
        • 13.2.1.1. The system default printer
        • 13.2.1.2. Device classes
        • 13.2.1.3. Getting status information
      • 13.2.2. Manipulating Individual Print Requests
      • 13.2.3. Managing Queues
      • 13.2.4. Starting and Stopping the Print Service
      • 13.2.5. Managing Printers and Destination Classes
        • 13.2.5.1. Defining or modifying a printer
        • 13.2.5.2. Deleting printers
        • 13.2.5.3. Managing device classes
        • 13.2.5.4. In-queue priorities
          • 13.2.5.4.1. Priorities under HP-UX
          • 13.2.5.4.2. Priorities under Solaris
        • 13.2.5.5. Printer interface programs
      • 13.2.6. Remote Printing
        • 13.2.6.1. HP-UX remote printing
        • 13.2.6.2. Solaris remote printing
      • 13.2.7. Adding a New Printer
      • 13.2.8. System V Spooling System Variations
        • 13.2.8.1. Solaris: Additional configuration files
        • 13.2.8.2. Solaris: Controlling printer access
        • 13.2.8.3. Solaris: Forms and filters
        • 13.2.8.4. HP-UX: Altering pending print jobs
        • 13.2.8.5. HP-UX: Analyzing printer usage
        • 13.2.8.6. Graphical administration tools
    • 13.3. The AIX Spooling Facility
      • 13.3.1. Manipulating Print Jobs
        • 13.3.1.1. Job numbers
        • 13.3.1.2. The default print queue under AIX
        • 13.3.1.3. Displaying job and queue status information
        • 13.3.1.4. Deleting print jobs
        • 13.3.1.5. Moving jobs between queues
        • 13.3.1.6. Suspending print jobs
        • 13.3.1.7. Print job priorities
      • 13.3.2. Managing Queues and Devices
      • 13.3.3. The qdaemon Server Process
      • 13.3.4. Configuring Queues: The /etc/qconfig File
        • 13.3.4.1. Creating and modifying print queues
      • 13.3.5. Remote Printing
      • 13.3.6. Adding a New Printer
      • 13.3.7. Using the Queueing System as a Batch Service
    • 13.4. Troubleshooting Printers
    • 13.5. Sharing Printers with Windows Systems
      • 13.5.1. Printing to a Windows Printer from a Unix System
      • 13.5.2. Accepting Incoming Windows Print Jobs via Samba
        • 13.5.2.1. Creating queues for the Samba printers under Windows
    • 13.6. LPRng
      • 13.6.1. Enhancements to the lpc Command
        • 13.6.1.1. Print classes and job priorities
      • 13.6.2. Configuring LPRng
        • 13.6.2.1. Separate client and server entries
        • 13.6.2.2. Using a common printcap file for many hosts
        • 13.6.2.3. Special-purpose queues
          • 13.6.2.3.1. Bounce queues
          • 13.6.2.3.2. Printer pools
        • 13.6.2.4. Filters
        • 13.6.2.5. Other printcap entry options
      • 13.6.3. Global Print Spooler Settings
      • 13.6.4. Printer Access Control
        • 13.6.4.1. Other LPRng capabilities
    • 13.7. CUPS
      • 13.7.1. Printer Administration
        • 13.7.1.1. CUPS configuration files
        • 13.7.1.2. Access control and authentication
    • 13.8. Font Management Under X
      • 13.8.1. Font Basics
      • 13.8.2. Managing Fonts under X
      • 13.8.3. Adding Fonts to X
        • 13.8.3.1. Printing support
      • 13.8.4. Handling TrueType Fonts
  • 14. Automating Administrative Tasks
    • 14.1. Creating Effective Shell Scripts
      • 14.1.1. Password File Security
      • 14.1.2. Monitoring Disk Usage
      • 14.1.3. Root Filesystem Backups and System Snapshots
      • 14.1.4. A Few More Tricks
      • 14.1.5. Testing and Debugging Scripts
    • 14.2. Perl: An Alternate Administrative Language
      • 14.2.1. A Quick Introduction
      • 14.2.2. A Walking Tour of Perl
      • 14.2.3. Perl Reports
      • 14.2.4. Graphical Interfaces with Perl
    • 14.3. Expect: Automating Interactive Programs
      • 14.3.1. A First Example: Testing User Environments
      • 14.3.2. A Timed Prompt
      • 14.3.3. Repeating a Command Over and Over
      • 14.3.4. Automating Configuration File Distribution
      • 14.3.5. Keep Trying Until It Works
    • 14.4. When Only C Will Do
    • 14.5. Automating Complex Configuration Tasks with Cfengine
      • 14.5.1. About Cfengine
      • 14.5.2. Actions
      • 14.5.3. Classes
      • 14.5.4. Configuring cfservd
      • 14.5.5. Running Cfengine
    • 14.6. Stem: Simplified Creation of Client-Server Applications
    • 14.7. Adding Local man Pages
  • 15. Managing System Resources
    • 15.1. Thinking About System Performance
      • 15.1.1. The Tuning Process
        • 15.1.1.1. Define the problem in as much detail as you can.
        • 15.1.1.2. Determine what's causing the problem.
        • 15.1.1.3. Formulate explicit performance improvement goals.
        • 15.1.1.4. Design and implement modifications to the system and applications to achieve those goals.
        • 15.1.1.5. Monitor the system to determine how well the changes worked.
        • 15.1.1.6. Return to the first step and begin again.
      • 15.1.2. Some Tuning Caveats
    • 15.2. Monitoring and Controlling Processes
      • 15.2.1. The ps Command
      • 15.2.2. Other Process Listing Utilities
      • 15.2.3. The /proc Filesystem
      • 15.2.4. Kernel Idle Processes
      • 15.2.5. Process Resource Limits
      • 15.2.6. Process Resource Limits Under AIX
      • 15.2.7. Signaling and Killing Processes
        • 15.2.7.1. Killing multiple processes with killall
        • 15.2.7.2. Processes that won't die
        • 15.2.7.3. Pausing and restarting processes
    • 15.3. Managing CPU Resources
      • 15.3.1. Nice Numbers and Process Priorities
      • 15.3.2. Monitoring CPU Usage
        • 15.3.2.1. Recognizing a CPU shortage
      • 15.3.3. Changing a Process's Nice Number
        • 15.3.3.1. renice under AIX, HP-UX, and Tru64
        • 15.3.3.2. Changing process priorities under Solaris
        • 15.3.3.3. Setting a user's default nice numbers under Tru64
      • 15.3.4. Configuring the System Scheduler
        • 15.3.4.1. The AIX scheduler
        • 15.3.4.2. The Solaris scheduler
        • 15.3.4.3. Tru64
      • 15.3.5. Unix Batch-Processing Facilities
    • 15.4. Managing Memory
      • 15.4.1. Monitoring Memory Use and Paging Activity
        • 15.4.1.1. Determining the amount of physical memory
        • 15.4.1.2. Monitoring memory use
        • 15.4.1.3. Recognizing memory problems
        • 15.4.1.4. The filesystem cache
      • 15.4.2. Configuring the Virtual Memory Manager
        • 15.4.2.1. AIX
        • 15.4.2.2. FreeBSD
        • 15.4.2.3. HP-UX
        • 15.4.2.4. Linux
        • 15.4.2.5. Solaris
        • 15.4.2.6. Tru64
      • 15.4.3. Managing Paging Space
        • 15.4.3.1. How much paging space?
        • 15.4.3.2. Listing paging areas
        • 15.4.3.3. Activating paging areas
        • 15.4.3.4. Creating new paging areas
        • 15.4.3.5. Filesystem paging
        • 15.4.3.6. Linux and HP-UX paging space priorities
        • 15.4.3.7. Removing paging areas
    • 15.5. Disk I/O Performance Issues
      • 15.5.1. Monitoring Disk I/O Performance
      • 15.5.2. Getting the Most From the Disk Subsystem
        • 15.5.2.1. Disk hardware
        • 15.5.2.2. Distributing the data among the available disks
        • 15.5.2.3. Data placement on disk
      • 15.5.3. Tuning Disk I/O Performance
        • 15.5.3.1. Sequential read-ahead
          • 15.5.3.1.1. AIX
          • 15.5.3.1.2. Linux
        • 15.5.3.2. Disk I/O pacing
    • 15.6. Monitoring and Managing Disk Space Usage
      • 15.6.1. Where Did It All Go?
      • 15.6.2. Handling Disk Shortage Problems
        • 15.6.2.1. Using find to locate or remove wasted space
        • 15.6.2.2. Limiting the growth of log files
      • 15.6.3. Controlling Disk Usage with Disk Quotas
        • 15.6.3.1. Preparing filesystems for quotas
        • 15.6.3.2. Setting users' quota limits
        • 15.6.3.3. Setting the soft limit expiration period
        • 15.6.3.4. Enabling quota checking
        • 15.6.3.5. Quota consistency checking
        • 15.6.3.6. Disk quota reports
        • 15.6.3.7. Group-based quotas (AIX, FreeBSD, Tru64 and Linux)
    • 15.7. Network Performance
      • 15.7.1. Basic Network Performance Monitoring
      • 15.7.2. General TCP/IP Network Performance Principles
        • 15.7.2.1. Two TCP parameters
      • 15.7.3. DNS Performance
      • 15.7.4. NFS Performance
        • 15.7.4.1. NFS Version 3 performance improvements
        • 15.7.4.2. NFS performance principles
  • 16. Configuring and Building Kernels
    • 16.1. FreeBSD and Tru64
      • 16.1.1. Changing FreeBSD Kernel Parameters
      • 16.1.2. FreeBSD Kernel Modules
      • 16.1.3. Installing the FreeBSD Boot Loader
      • 16.1.4. Tru64 Dynamic Kernel Configuration
    • 16.2. HP-UX
    • 16.3. Linux
      • 16.3.1. Using lilo
        • 16.3.1.1. Using a graphical message screen
        • 16.3.1.2. lilo and Windows
        • 16.3.1.3. More complex booting scenarios
        • 16.3.1.4. lilo's -r option
        • 16.3.1.5. The boot.message file
      • 16.3.2. The Grub Boot Loader
      • 16.3.3. Booting a Linux System with syslinux
      • 16.3.4. Restoring the DOS Master Boot Program
      • 16.3.5. Booting Alpha Linux Systems
      • 16.3.6. Linux Loadable Modules
    • 16.4. Solaris
    • 16.5. AIX System Parameters
  • 17. Accounting
    • 17.1. Standard Accounting Files
    • 17.2. BSD-Style Accounting: FreeBSD, Linux, and AIX
      • 17.2.1. Enabling and Disabling Accounting
      • 17.2.2. Merging Accounting Records into the Summary Files
      • 17.2.3. After a Crash
      • 17.2.4. Image-Based Resource Use Reporting: sa
      • 17.2.5. Connect Time Reporting: ac
    • 17.3. System V-Style Accounting: AIX, HP-UX, and Solaris
      • 17.3.1. Setting Up Accounting
      • 17.3.2. Accounting Reports
      • 17.3.3. Solaris Project-Based Extended Accounting
      • 17.3.4. The upacct Package
    • 17.4. Printing Accounting
      • 17.4.1. Printer Accounting Under LPRng
  • 18. The Profession of System Administration
    • SAGE: The System Administrators Guild
    • Administrative Virtues
  • A. Administrative Shell Programming
    • A.1. Basic Syntax
      • A.1.1. I/O Redirection
      • A.1.2. The dot Command
      • A.1.3. Return Codes and the exit Command
      • A.1.4. Compound Commands
      • A.1.5. Command Substitution
      • A.1.6. Argument Symbols and Other $ Abbreviations
      • A.1.7. Variable Substitution
        • A.1.7.1. bash variable substitution extensions
      • A.1.8. Variable Double Dereferencing
    • A.2. The if Statement
      • A.2.1. The test Command (a.k.a. [ )
    • A.3. Other Control Structures
      • A.3.1. The while and until Commands
      • A.3.2. The case Command
      • A.3.3. The for Command
        • A.3.3.1. The bash arithmetic for loop
      • A.3.4. The Null Command
    • A.4. Getting Input: The read Command
      • A.4.1. The bash select command
    • A.5. Other Useful Commands
      • A.5.1. set
      • A.5.2. eval
      • A.5.3. printf
      • A.5.4. expr
        • A.5.4.1. bash integer arithmetic
        • A.5.4.2. bash arrays
    • A.6. Shell Functions
      • A.6.1. bash Local Variables
  • Colophon
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