Absolute BSD—The Ultimate Guide to FreeBSD

Table of Contents
Absolute BSD—The Ultimate Guide to FreeBSD............................................................................	1
Dedication..........................................................................................................................................	3
Foreword............................................................................................................................................	4
Introduction........................................................................................................................................	5
What Is FreeBSD?...................................................................................................................	5
How Did FreeBSD Get Here?..................................................................................................	5
The BSD License: BSD Goes Public.......................................................................................	6
The Birth of Modern FreeBSD.................................................................................................	6
FreeBSD Development............................................................................................................	7
Committers.........................................................................................................................	7
Contributors........................................................................................................................	8
Users..................................................................................................................................	8
Other BSDs..............................................................................................................................	8
NetBSD..............................................................................................................................	8
OpenBSD...........................................................................................................................	9
BSD/OS..............................................................................................................................	9
Mac OS X...........................................................................................................................	9
Other UNIXes...........................................................................................................................	9
Solaris................................................................................................................................	9
AIX...................................................................................................................................	10
Linux................................................................................................................................	10
IRIX, HPUX, etc...............................................................................................................	10
FreeBSD's Strengths.............................................................................................................	10
Portability.........................................................................................................................	10
Power...............................................................................................................................	10
Simplified Software Management....................................................................................	11
Optimized Upgrade Process............................................................................................	11
Filesystem........................................................................................................................	11
Who Should Use FreeBSD....................................................................................................	11
FreeBSD as Your Desktop.....................................................................................................	11
Who Should Run Another BSD..............................................................................................	12
Who Should Run a Proprietary Operating System................................................................	12
How to Read This Book.........................................................................................................	13
What Must You Know?..........................................................................................................	13
How to Think About UNIX......................................................................................................	14
Channels of Communication............................................................................................	14
Working with Channels....................................................................................................	14
The Command Line..........................................................................................................	14
Chapter 1: Installation.....................................................................................................................	16
FreeBSD Hardware................................................................................................................	16
Processor.........................................................................................................................	16
Memory (RAM).................................................................................................................	16
Hard Drives......................................................................................................................	16
Downloading FreeBSD..........................................................................................................	17
Installing by FTP..............................................................................................................	18
Other FTP Install Information...........................................................................................	19
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Table of Contents
Chapter 1: Installation
Hardware Setup.....................................................................................................................	19
Actually Installing FreeBSD...................................................................................................	20
Configuring the Kernel for ISA Cards...............................................................................	21
Sysinstall: The Ugly FreeBSD Installer............................................................................	21
Disk Usage.......................................................................................................................	22
Partitioning.............................................................................................................................	24
Root.......................................................................................................................................	25
Swap Space...........................................................................................................................	25
Swap Splitting..................................................................................................................	26
/var, /usr, and /home..............................................................................................................	26
A Second Hard Drive.............................................................................................................	27
Soft Updates....................................................................................................................	28
Block Size........................................................................................................................	28
What to Install..................................................................................................................	28
Installation Media.............................................................................................................	29
Committing.......................................................................................................................	30
Post−Install Setup..................................................................................................................	30
Root Password.................................................................................................................	30
Adding Users....................................................................................................................	31
Time Zone........................................................................................................................	32
Mouse..............................................................................................................................	32
Configuring Network Cards..............................................................................................	33
Xfree86............................................................................................................................	35
Software...........................................................................................................................	35
Restart...................................................................................................................................	36
A Note on Editors...................................................................................................................	37
Chapter 2: Getting More Help.........................................................................................................	38
Why Not Mail First?................................................................................................................	38
The FreeBSD Attitude............................................................................................................	38
Man Pages.............................................................................................................................	39
The FreeBSD Manual......................................................................................................	40
Man Page Headings.........................................................................................................	41
The FreeBSD Documentation................................................................................................	42
The Mailing List Archives.......................................................................................................	42
Other Web Sites.....................................................................................................................	43
Using FreeBSD Problem−Solving Resources........................................................................	43
Checking the Handbook/FAQ..........................................................................................	43
Checking the Man Pages.................................................................................................	43
Checking the Mailing List Archives..................................................................................	45
Using Your Answer..........................................................................................................	45
Mailing for Help................................................................................................................	45
Chapter 3: Read This Before You Break Something Else! (Backup and Recovery).................	48
Overview................................................................................................................................	48
System Backups....................................................................................................................	48
Tape Devices.........................................................................................................................	49
How to Read Dmesg.boot................................................................................................	49
Controlling Your Tape Drive...................................................................................................	50
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Table of Contents
Chapter 3: Read This Before You Break Something Else! (Backup and Recovery)
Device Nodes...................................................................................................................	50
Using the TAPE Variable.................................................................................................	50
The mt Command............................................................................................................	51
Backup Programs..................................................................................................................	52
Tar....................................................................................................................................	52
Dump/Restore..................................................................................................................	55
Restoring from an Archive.....................................................................................................	58
Checking the Contents of an Archive...............................................................................	58
Extracting Data from an Archive......................................................................................	58
Restoring Interactively......................................................................................................	59
Recording What Happened....................................................................................................	60
Revision Control.....................................................................................................................	61
Getting Older Versions.....................................................................................................	63
Breaking Locks.................................................................................................................	64
Viewing Log Messages....................................................................................................	64
Reviewing a File's Revision History.................................................................................	65
Ident and ident Strings.....................................................................................................	65
Going Further...................................................................................................................	66
Single−User Mode.................................................................................................................	66
The Fixit Disk.........................................................................................................................	68
Chapter 4: Kernel Games................................................................................................................	70
Overview................................................................................................................................	70
What Is the Kernel?...............................................................................................................	70
Configuring Your Kernel.........................................................................................................	71
Sysctl................................................................................................................................	71
Changing Sysctls.............................................................................................................	74
Setting Sysctls at Boot.....................................................................................................	74
Kernel Configuration with Loader.conf.............................................................................	75
Manually Configuring the Loader.....................................................................................	77
Loading and Unloading Modules in Multi−User Mode...........................................................	78
Viewing Loaded Modules.................................................................................................	78
Loading and Unloading Modules......................................................................................	79
Customizing the Kernel..........................................................................................................	79
Preparation.......................................................................................................................	79
Your Backup Kernel.........................................................................................................	80
Editing Kernel Files..........................................................................................................	80
Basic Options...................................................................................................................	83
Multiple Processors..........................................................................................................	86
Device Entries..................................................................................................................	86
Building Your Kernel..............................................................................................................	89
Troubleshooting Kernel Builds.........................................................................................	90
Booting an Alternate Kernel...................................................................................................	91
Adding to the Kernel..............................................................................................................	92
LINT.................................................................................................................................	92
Fixing Errors with Options................................................................................................	93
Tweaking Kernel Performance...............................................................................................	94
Sharing Kernels.....................................................................................................................	96

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Table of Contents
Chapter 5: Networking....................................................................................................................	97
Overview................................................................................................................................	97
Network Layers......................................................................................................................	97
The Physical Layer...........................................................................................................	98
The Physical Protocol Layer............................................................................................	98
The Logical Protocol Layer..............................................................................................	99
The Application Layer....................................................................................................	100
The Network in Practice.......................................................................................................	100
Mbufs.............................................................................................................................	101
What Is a Bit?.................................................................................................................	101
Ethernet...............................................................................................................................	102
Broadcasting..................................................................................................................	103
Address Resolution........................................................................................................	103
Hubs and Switches........................................................................................................	103
Netmasks.......................................................................................................................	104
Netmask Tricks..............................................................................................................	105
Hexadecimal Netmasks.................................................................................................	105
Unusable IP Addresses..................................................................................................	106
Routing...........................................................................................................................	106
UDP and TCP................................................................................................................	107
Network Ports.................................................................................................................	107
Connecting to an Ethernet Network.....................................................................................	108
Multiple IP Addresses on One Interface.........................................................................	110
Using Netstat..................................................................................................................	111
Chapter 6: Upgrading FreeBSD....................................................................................................	116
Overview..............................................................................................................................	116
FreeBSD Versions...............................................................................................................	116
Release..........................................................................................................................	116
FreeBSD−current...........................................................................................................	117
FreeBSD−stable.............................................................................................................	117
Snapshots......................................................................................................................	118
Security Updates............................................................................................................	118
Which Release Should You Use?..................................................................................	119
Upgrade Methods................................................................................................................	119
Upgrading via Sysinstall.................................................................................................	119
Upgrading via CVSup.....................................................................................................	120
Simplifying the CVSup Upgrade Process.......................................................................	130
Building a Local CVSup Server............................................................................................	132
Controlling Access.........................................................................................................	134
Authentication................................................................................................................	135
Combining Authentication and Access...........................................................................	137
Chapter 7: Securing Your System................................................................................................	138
Overview..............................................................................................................................	138
Who Is the Enemy?..............................................................................................................	138
Script Kiddies.................................................................................................................	139
Disaffected Users...........................................................................................................	139
Skilled Attackers.............................................................................................................	139
FreeBSD Security Announcements.....................................................................................	139
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Table of Contents
Chapter 7: Securing Your System
Subscribing....................................................................................................................	140
What You'll Get..............................................................................................................	140
Installation Security Profiles.................................................................................................	141
Moderate........................................................................................................................	141
Extreme..........................................................................................................................	141
Root, Groups, and Permissions...........................................................................................	141
The root Password.........................................................................................................	142
Groups of Users.............................................................................................................	142
Primary Group................................................................................................................	143
Some Interesting Default Groups...................................................................................	143
Group Permissions.........................................................................................................	144
Changing Permissions.........................................................................................................	145
Changing File Ownership...............................................................................................	146
Assigning Permissions...................................................................................................	147
File Flags.............................................................................................................................	148
Viewing a File's Flags....................................................................................................	149
Setting Flags..................................................................................................................	149
Securelevels........................................................................................................................	150
Setting Securelevels......................................................................................................	150
Which Securelevel Do You Need?.................................................................................	152
What Won't Securelevel and File Flags Do?..................................................................	152
Living with Securelevels.................................................................................................	153
Programs That Can Be Hacked...........................................................................................	153
Putting It All Together..........................................................................................................	156
Chapter 8: Advanced Security Features......................................................................................	157
Traffic Control......................................................................................................................	157
Default Accept vs. Default Deny....................................................................................	157
TCP Wrappers.....................................................................................................................	158
Configuring Wrappers....................................................................................................	158
Daemon Name...............................................................................................................	158
The Client List................................................................................................................	159
Putting It All Together.....................................................................................................	165
Packet Filtering....................................................................................................................	166
IPFilter............................................................................................................................	166
IPFW..............................................................................................................................	167
Default Accept and Default Deny in Packet Filtering.....................................................	167
Basic Concepts of Packet Filtering................................................................................	167
Implementing IPFilter.....................................................................................................	168
Configuring Your Server to Use Jail...............................................................................	176
Configuring Your Kernel to Use Jail...............................................................................	177
Client Setup....................................................................................................................	178
Final Jail Setup...............................................................................................................	181
Starting the Jail..............................................................................................................	182
Managing Jails...............................................................................................................	182
Shutting Down a Jail......................................................................................................	183
Monitoring System Security.................................................................................................	183
If You're Hacked...................................................................................................................	184

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Table of Contents
Chapter 9: Too Much Information About /etc..............................................................................	185
Overview..............................................................................................................................	185
Varieties of /etc Files............................................................................................................	185
Default Files.........................................................................................................................	185
/etc/defaults/rc.conf........................................................................................................	186
/etc/adduser.conf............................................................................................................	186
/etc/crontab....................................................................................................................	188
/etc/csh.*........................................................................................................................	191
/etc/dhclient.conf............................................................................................................	191
/etc/fstab........................................................................................................................	192
/etc/ftp.*..........................................................................................................................	192
/etc/hosts.allow...............................................................................................................	193
/etc/hosts.equiv..............................................................................................................	193
/etc/hosts.lpd..................................................................................................................	193
/etc/inetd.conf.................................................................................................................	194
/etc/locate.rc...................................................................................................................	194
/etc/login.access.............................................................................................................	194
/etc/login.conf.................................................................................................................	197
Specifying Default Environment Settings.......................................................................	199
/etc/mail/mailer.conf.......................................................................................................	202
/etc/make.conf and /etc/defaults/make.conf...................................................................	202
/etc/master.passwd........................................................................................................	207
/etc/motd........................................................................................................................	208
/etc/mtree/*.....................................................................................................................	208
/etc/namedb/*.................................................................................................................	208
/etc/newsyslog.conf........................................................................................................	208
/etc/passwd....................................................................................................................	209
/etc/periodic.conf and /etc/defaults/periodic.conf...........................................................	209
/etc/printcap....................................................................................................................	210
Working with Printcap Entries........................................................................................	210
/etc/profile.......................................................................................................................	212
/etc/protocols..................................................................................................................	213
/etc/pwd.db.....................................................................................................................	213
/etc/rc.............................................................................................................................	214
/etc/rc.conf and /etc/defaults/rc.conf..............................................................................	215
/etc/resolv.conf...............................................................................................................	221
/etc/security....................................................................................................................	221
/etc/services...................................................................................................................	222
/etc/shells.......................................................................................................................	222
/etc/spwd.db...................................................................................................................	222
/etc/ssh...........................................................................................................................	222
/etc/sysctl.conf................................................................................................................	222
/etc/syslog.conf..............................................................................................................	222
Chapter 10: Making Your System Useful.....................................................................................	223
Overview..............................................................................................................................	223
Making Software..................................................................................................................	223
The Pain and Pleasure of Source Code.........................................................................	224
Debugging......................................................................................................................	225
The Ports and Packages System.........................................................................................	225
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Table of Contents
Chapter 10: Making Your System Useful
Ports...............................................................................................................................	225
Finding Software............................................................................................................	227
Legal Restrictions...........................................................................................................	229
Using Packages...................................................................................................................	229
Installing from CD−ROM................................................................................................	230
Installing via FTP............................................................................................................	231
What Does a Package Install?.......................................................................................	232
Uninstalling Packages....................................................................................................	234
Package Information......................................................................................................	234
Controlling Pkg_add.......................................................................................................	235
Package Problems.........................................................................................................	236
Forcing an Install............................................................................................................	237
Using Ports..........................................................................................................................	238
Installing a Port..............................................................................................................	239
Using Make Install..........................................................................................................	239
Built−In Port Features....................................................................................................	240
Uninstalling and Reinstalling..........................................................................................	243
Cleaning Up with Make Clean........................................................................................	244
Building Packages..........................................................................................................	244
Changing the Install Path...............................................................................................	245
Setting Make Options Permanently................................................................................	245
Upgrading Ports and Packages...........................................................................................	245
Upgrading the Ports Collection......................................................................................	246
Ports Collection Upgrade Issues....................................................................................	247
Checking Software Versions..........................................................................................	247
Hints for Upgrading........................................................................................................	248
Chapter 11: Advanced Software Management............................................................................	250
Overview..............................................................................................................................	250
Startup and Shutdown Scripts.............................................................................................	250
Typical Startup Script.....................................................................................................	251
Using Scripts to Manage Running Programs.................................................................	252
Managing Shared Libraries..................................................................................................	252
Ldconfig.........................................................................................................................	253
Running Software from the Wrong OS................................................................................	256
Recompilation................................................................................................................	256
Emulation.......................................................................................................................	257
ABI Implementation........................................................................................................	257
Foreign Software Libraries.............................................................................................	259
Installing and Enabling Linux Mode.....................................................................................	259
Identifying Programs......................................................................................................	260
What Is Linux_base?......................................................................................................	261
Adding to Linux_base.....................................................................................................	261
Configuring Linux Shared Libraries................................................................................	262
Installing Extra Linux Packages as RPMs......................................................................	263
Using Multiple Processors—SMP........................................................................................	263
What Is SMP?................................................................................................................	263
Kernel Assumptions.......................................................................................................	264
FreeBSD 3.0 SMP..........................................................................................................	265
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Table of Contents
Chapter 11: Advanced Software Management
FreeBSD 5 SMP.............................................................................................................	265
Using SMP.....................................................................................................................	266
SMP and Upgrades........................................................................................................	266
Chapter 12: Finding Hosts With DNS...........................................................................................	268
How DNS Works..................................................................................................................	268
Basic DNS Tools..................................................................................................................	269
The Host Command.......................................................................................................	269
Getting Detailed Information with Dig.............................................................................	269
Looking Up Hostnames with Dig....................................................................................	271
More Dig Options...........................................................................................................	272
Configuring a DNS Client: The Resolver.............................................................................	273
Domain or Search Keywords.........................................................................................	274
The Nameserver List......................................................................................................	275
DNS Information Sources....................................................................................................	275
The Hosts File................................................................................................................	275
The Named Daemon......................................................................................................	276
Zone Files......................................................................................................................	282
A Real Sample Zone............................................................................................................	286
named.conf....................................................................................................................	286
/var/named/master/absolutebsd.com.............................................................................	286
Making Changes Work.........................................................................................................	288
Starting Named at Boottime.................................................................................................	289
Checking DNS.....................................................................................................................	289
Named Configuration Errors..........................................................................................	290
Named Security...................................................................................................................	290
Controlling Information Order...............................................................................................	291
More About BIND.................................................................................................................	292
Chapter 13: Managing Small Network Services..........................................................................	293
Bandwidth Control................................................................................................................	293
Configuring IPFW...........................................................................................................	294
Reviewing IPFW Rules..................................................................................................	297
Dummynet Queues........................................................................................................	297
Directional Traffic Shaping.............................................................................................	298
Public−Key Encryption.........................................................................................................	298
Certificates.....................................................................................................................	299
Create a Request...........................................................................................................	299
Being Your Own CA.......................................................................................................	302
SSH......................................................................................................................................	303
Testing SSH...................................................................................................................	304
Enabling SSH.................................................................................................................	304
Basics of SSH................................................................................................................	304
Creating Keys.................................................................................................................	304
Confirming SSH Identity.................................................................................................	305
SSH Clients....................................................................................................................	305
Connecting via SSH.......................................................................................................	306
Configuring SSH............................................................................................................	306
System Time........................................................................................................................	309
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Chapter 13: Managing Small Network Services
Setting the Time Zone....................................................................................................	309
Network Time Protocol...................................................................................................	309
Ntpdate..........................................................................................................................	310
Ntpd...............................................................................................................................	310
Inetd.....................................................................................................................................	311
/etc/inetd.conf.................................................................................................................	311
Configuring Programs in Inetd.......................................................................................	312
Inetd Security.................................................................................................................	313
Starting Inetd..................................................................................................................	313
Changing Inetd's Behavior.............................................................................................	314
Chapter 14: Email Services...........................................................................................................	315
Email Overview....................................................................................................................	315
Where FreeBSD Fits In..................................................................................................	315
The Email Protocol.........................................................................................................	315
Email Programs...................................................................................................................	318
Who Needs Sendmail?..................................................................................................	319
Replacing Sendmail.......................................................................................................	319
Installing Postfix.............................................................................................................	319
Pieces of Postfix.............................................................................................................	319
Configuring Postfix.........................................................................................................	320
Email Aliases..................................................................................................................	323
Email Logging................................................................................................................	324
Virtual Domains..............................................................................................................	325
Postfix Commands.........................................................................................................	326
Finding the Correct Mail Host.........................................................................................	326
Undeliverable Mail..........................................................................................................	326
POP3...................................................................................................................................	327
Installing POP3..............................................................................................................	327
Testing POP3.................................................................................................................	327
POP3 Logging................................................................................................................	328
POP3 Modes..................................................................................................................	328
Qpopper Preconfiguration Questions.............................................................................	329
Default Qpopper Configuration......................................................................................	329
APOP Setup...................................................................................................................	332
Configuring Pop3ssl.......................................................................................................	333
Qpopper Security...........................................................................................................	334
Chapter 15: Web and FTP Services.............................................................................................	335
Overview..............................................................................................................................	335
How a Web Server Works....................................................................................................	335
The Apache Web Server......................................................................................................	336
Apache Configuration Files............................................................................................	336
Configuring Apache........................................................................................................	337
Controlling Apache.........................................................................................................	352
Virtual Hosting......................................................................................................................	355
Name−Based Virtual Hosts............................................................................................	356
IP−Based Virtual Hosts..................................................................................................	357
Tweaking Virtual Hosts..................................................................................................	357
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Table of Contents
Chapter 15: Web and FTP Services
.NET on FreeBSD................................................................................................................	359
Installing the SSCLI........................................................................................................	359
FTP......................................................................................................................................	360
FTP Security..................................................................................................................	360
The FTP Client...............................................................................................................	360
The FTP Server..............................................................................................................	362
Chapter 16: Filsystems and Disks...............................................................................................	367
Device Nodes.......................................................................................................................	367
Hard Disks and Partitions...............................................................................................	367
The /etc/fstab File................................................................................................................	368
Disk Basics..........................................................................................................................	369
The Fast File System...........................................................................................................	370
Vnodes...........................................................................................................................	371
FFS Mount Types...........................................................................................................	371
FFS Mount Options........................................................................................................	372
What's Mounted Now?.........................................................................................................	373
Dirty Disks............................................................................................................................	373
Fsck................................................................................................................................	373
Mounting and Unmounting Disks.........................................................................................	375
Mounting Standard Filesystems.....................................................................................	375
Mounting with Options....................................................................................................	375
Forcing Read−Write Mounts..........................................................................................	375
Mounting All Standard Filesystems................................................................................	376
Mounting at Nonstandard Locations..............................................................................	376
Unmounting....................................................................................................................	376
Soft Updates........................................................................................................................	376
Enabling Soft Updates...................................................................................................	377
IDE Write Caching and Soft Updates.............................................................................	377
Virtual Memory Directory Caching.......................................................................................	378
Mounting Foreign Filesystems.............................................................................................	378
Using Foreign Mounts....................................................................................................	378
Foreign Filesystem Types..............................................................................................	379
Mount Options and Foreign Filesystems........................................................................	380
Filesystem Permissions.......................................................................................................	380
Removable Media and /etc/fstab.........................................................................................	381
Creating a Floppy.................................................................................................................	381
Low−Level Formatting....................................................................................................	381
Creating an FFS Filesystem...........................................................................................	381
Creating an MS−DOS Filesystem..................................................................................	382
The Basics of SCSI..............................................................................................................	382
SCSI Types....................................................................................................................	383
SCSI Adapters...............................................................................................................	383
SCSI Buses....................................................................................................................	383
Termination and Cabling................................................................................................	383
SCSI IDs and LUNs.......................................................................................................	384
FreeBSD and SCSI..............................................................................................................	384
Boot−Time Delay...........................................................................................................	384
Wiring Down Devices.....................................................................................................	385
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Table of Contents
Chapter 16: Filsystems and Disks
Adding New Hard Disks.......................................................................................................	386
Creating Slices...............................................................................................................	386
Creating Partitions..........................................................................................................	387
Configuring /etc/fstab.....................................................................................................	388
Installing Existing Files onto New Disks.........................................................................	388
Temporary Mounts.........................................................................................................	388
Moving Files...................................................................................................................	389
Stackable Mounts...........................................................................................................	389
Chapter 17: RAID...........................................................................................................................	391
Hardware vs. Software RAID...............................................................................................	391
RAID Levels.........................................................................................................................	391
Software RAID.....................................................................................................................	392
Vinum Disk Components................................................................................................	392
Vinum Plex Types..........................................................................................................	393
RAID−5 Plex..................................................................................................................	393
Preparing Vinum Drives.................................................................................................	393
Dedicating Partitions to Vinum.......................................................................................	394
Configuring Vinum..........................................................................................................	395
Concatenated Plex.........................................................................................................	396
Removing Vinum Configuration.....................................................................................	398
Striped Volumes.............................................................................................................	399
Mirrored Volumes...........................................................................................................	400
Starting Vinum at Boot...................................................................................................	401
Other Vinum Commands................................................................................................	402
Replacing a Failed Mirrored Plex...................................................................................	402
Chapter 18: System Performance................................................................................................	406
Overview..............................................................................................................................	406
Computer Resources...........................................................................................................	406
Disk Input/Output.................................................................................................................	407
Network Bandwidth..............................................................................................................	407
CPU and Memory................................................................................................................	407
Using Top.......................................................................................................................	408
Memory Usage...............................................................................................................	411
Swap Space Usage........................................................................................................	411
CPU Usage....................................................................................................................	412
When Swap Goes Bad.........................................................................................................	414
Paging............................................................................................................................	414
Swapping.......................................................................................................................	415
Are You Swapping or Paging?.......................................................................................	415
Real−World Performance Tuning.........................................................................................	418
Fairness in Benchmarking..............................................................................................	418
The Initial Test................................................................................................................	418
Using Both CPUs...........................................................................................................	420
Directory Caching...........................................................................................................	421
Moving /usr/obj...............................................................................................................	421
Lessons Learned.................................................................................................................	423

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Chapter 19: Now What's It Doing?...............................................................................................	424
Status Mails.........................................................................................................................	424
Forwarding Reports........................................................................................................	424
Logging with Syslogd...........................................................................................................	424
Facilities.........................................................................................................................	424
Levels.............................................................................................................................	425
Syslog.conf.....................................................................................................................	426
Wildcards.......................................................................................................................	426
Rotating Logs with Newsyslog.conf...............................................................................	429
Reporting with SNMP...........................................................................................................	433
Basics of SNMP.............................................................................................................	433
MIBs...............................................................................................................................	433
Net−snmp.......................................................................................................................	434
Snmpwalk.......................................................................................................................	435
Specific Snmpwalk Queries...........................................................................................	435
Translating Between Numbers and Names...................................................................	436
Setting Up Snmpd..........................................................................................................	437
Index Numbers...............................................................................................................	441
Long−Term Monitoring with MRTG......................................................................................	441
Configuring MRTG.........................................................................................................	442
Sample mrtg.cfg Entry....................................................................................................	442
Testing MRTG................................................................................................................	444
Tracking Other System Values......................................................................................	445
Useful Net−snmp MIBs..................................................................................................	445
Monitoring a Single MIB.................................................................................................	446
Customizing MRTG........................................................................................................	447
MRTG Index Page.........................................................................................................	448
Sample MRTG Configurations.......................................................................................	448
Monitoring Non−BSD Systems......................................................................................	450
Chapter 20: System Crashes and Panics....................................................................................	452
What Causes Panics?..........................................................................................................	452
What Does a Panic Look Like?......................................................................................	452
Responding to a Panic.........................................................................................................	453
Prerequisites..................................................................................................................	454
Crash Dump Process.....................................................................................................	454
The Debugging Kernel...................................................................................................	454
Post−Panic Behavior......................................................................................................	455
kernel.debug..................................................................................................................	455
Dumpon..........................................................................................................................	456
Savecore........................................................................................................................	456
Upon a Crash.................................................................................................................	456
Dumps and Bad Kernels................................................................................................	456
Using the Dump...................................................................................................................	457
Advanced Kernel Debugging.........................................................................................	459
Examining Lines.............................................................................................................	460
Examining Variables......................................................................................................	460
Apparent Gdb Weirdness...............................................................................................	462
Results...........................................................................................................................	462
Vmcore and Security......................................................................................................	463
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Table of Contents
Chapter 20: System Crashes and Panics
Symbols vs. No Symbols...............................................................................................	463
Serial Consoles....................................................................................................................	465
Hardware Serial Console...............................................................................................	465
Software Serial Console.................................................................................................	465
Changing the Configuration...........................................................................................	466
Using a Serial Console...................................................................................................	467
Serial Login....................................................................................................................	469
Emergency Logon Setup................................................................................................	469
Disconnecting the Serial Console..................................................................................	470
Submitting a Problem Report...............................................................................................	471
Problem Report System.................................................................................................	471
What's in a PR?.............................................................................................................	471
Using Send−pr...............................................................................................................	471
Filling Out the Form........................................................................................................	472
PR Results.....................................................................................................................	474
Chapter 21: Desktop FreeBSD......................................................................................................	475
Overview..............................................................................................................................	475
Accessing File Shares.........................................................................................................	475
Prerequisites..................................................................................................................	475
Character Sets...............................................................................................................	476
Kernel Support for CIFS.................................................................................................	476
SMB Tools......................................................................................................................	476
Configuring CIFS............................................................................................................	476
Minimum Configuration: Name Resolution.....................................................................	478
Other smbutil Functions.................................................................................................	478
Mounting a Share...........................................................................................................	479
Other mount_smbfs Options..........................................................................................	480
Sample nsmb.conf Entries.............................................................................................	480
CIFS File Ownership......................................................................................................	481
Serving Windows File Shares..............................................................................................	481
Accessing Print Servers.......................................................................................................	482
Lpd.................................................................................................................................	482
Running a Local Lpd......................................................................................................	483
Printer Testing................................................................................................................	483
Local Printers.......................................................................................................................	484
X: A Graphic Interface..........................................................................................................	484
X Prerequisites...............................................................................................................	484
X Versions......................................................................................................................	484
Configuring X.................................................................................................................	485
Making X Look Decent...................................................................................................	485
Desktop Applications...........................................................................................................	486
Web Browsers................................................................................................................	486
Email Readers................................................................................................................	486
Office Suites...................................................................................................................	487
Music..............................................................................................................................	488
Graphics.........................................................................................................................	488
Desk Utilities..................................................................................................................	488
Games............................................................................................................................	489
xiii

Table of Contents
Afterword........................................................................................................................................	491
Overview..............................................................................................................................	491
The Community....................................................................................................................	491
What Can You Do?..............................................................................................................	492
If Nothing Else …...........................................................................................................492
Getting Things Done............................................................................................................	493
Second Opinions............................................................................................................	493
Do It!....................................................................................................................................	494
Appendix: Some Useful SYSCTL MIBs........................................................................................	495
List of Figures................................................................................................................................	507
Chapter 1: Installation..........................................................................................................	507
Chapter 5: Networking.........................................................................................................	507
Chapter 6: Upgrading FreeBSD...........................................................................................	507
Chapter 19: Now What's It Doing?.......................................................................................	507
List of Tables..................................................................................................................................	508
Chapter 4: Kernel Games....................................................................................................	508
Chapter 5: Networking.........................................................................................................	508
Chapter 8: Advanced Security Features..............................................................................	508
Chapter 9: Too Much Information About /etc.......................................................................	508
List of Sidebars..............................................................................................................................	509
Chapter 15: Web and FTP Services....................................................................................	509

xiv

Absolute BSD—The Ultimate Guide to FreeBSD

Michael Lucas

NO STARCH PRESS San Francisco

Copyright © 2002 Michael Lucas

All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher.

1 2 3 4 5 6 7 8 9 10–05 04 03 02

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Library of Congress Cataloguing−in−Publication Data

Lucas, Michael, 1967−

Absolute BSD : the ultimate guide to FreeBSD / Michael Lucas.

p. cm.

1

Includes index.

1−886411−74−3 (pbk.)

1. FreeBSD. 2. UNIX (Computer file) 3. Internet service

providers−−Computer programs. 4. Web servers−−Computer programs. 5.

Client/server computing. I. Title.

QA76.76.O63 L83 2002

005.4'4769−−dc21

2