Essential System Administration · 3rd Edition by Frisch, Æleen -- Read -- Imperial Library of Trantor

Index

Essential System Administration, 3rd Edition

SPECIAL OFFER: Upgrade this ebook with O’Reilly 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 Won't 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 SPECIAL OFFER: Upgrade this ebook with O’Reilly

← Prev
Back
Next →

← Prev
Back
Next →