Linux Samba Server Administration - arsamandish.com

635 Pages·2009·3.88 MB·English

Linux Samba Server
Administration
Roderick W. Smith
San Francisco Paris Düsseldorf Soest London
Associate Publisher: Neil Edde
Contracts and Licensing Manager: Kristine O’Callaghan
Acquisitions Editor: Maureen Adams
Developmental Editor: Thomas Cirtin
Editors: Carol Henry, Pete Gaughan
Production Editor: Shannon Murphy
Technical Editor: Elizabeth Zinkann
Book Designer: Bill Gibson
Graphic Illustrator: Tony Jonick
Electronic Publishing Specialist: Nila Nichols
Proofreaders: Jennifer Campbell, Erika Donald, Nanette Duffy, Laurie O’Connell, Nancy Riddiough,
Nathan Whiteside
Indexer: Nancy Guenther
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Cover Illustrator: Ingalls & Associates
Copyright © 2001 SYBEX Inc., 1151 Marina Village Parkway, Alameda, CA 94501. World rights reserved.
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Library of Congress Card Number: 00-107350
ISBN: 0-7821-2740-1
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Foreword
Microsoft Windows holds the lion’s share of the desktop operating system market. The
majority of clients connecting to a Linux server are Microsoft Windows clients. Effec-
tively serving those clients is a major task for every Linux system administrator. Samba
is an important tool for tackling that task.
Most of the network services provided by a Linux server are standard Internet services.
Apache, DHCP, DNS, and sendmail are all topics covered in the Craig Hunt Linux
Library and are all services built on standard Internet protocols. Samba is different. It
implements the NetBIOS and Server Message Block (SMB) protocols that Microsoft uses
for its proprietary networking. Samba integrates a Linux server into a Microsoft network
almost seamlessly. This makes Samba an extremely important component of the Linux
system administrator’s toolkit.
In 1999, I attended two talks given by Andrew Tridgell at the Open Source Software Con-
vention. Because I already knew I wanted to include a book about Samba in the Craig Hunt
Linux Library, I was struck by something he said. Andrew, a leader of the Samba devel-
opment team, said that people were always asking him to write a book about Samba but
that he thought the best book about Samba would be written by a system administrator,
not a software developer. I had to agree with him, and I was lucky enough to find an
author with system administration skills who really knows how to write. That author is
Rod Smith.
Rod is the author of several books, all of which focus on Linux. He has written about
Linux hardware, Linux networking, and Linux applications, and all of his books are
highly rated. I was pleased to find an author of his skill who also understands the impor-
tance of producing top-quality books for the Linux system administrator—which is the
entire reason the Craig Hunt Linux Library was created. By the time I had finished his
first chapter, I knew we had found the right person to write Linux Samba Server Admin-
istration. I hope you enjoy reading Rod’s book as much as I did.
Craig Hunt
October 2000
Acknowledgments
A book doesn’t just happen. At every point along the way from project beginning to fin-
ished product, many people other than the author have their influence. This book began
with Craig Hunt’s conception for a series of Linux system administration titles, and his
influence on this book has continued through his comments and suggestions on each
chapter. Maureen Adams, acquisitions editor, helped set the book on course at its incep-
tion. Tom Cirtin, development editor, guided the book’s development, especially for the
critical first few chapters. As production editor, Shannon Murphy coordinated the work
of the many others who contributed their thoughts to the book. Editors Carol Henry and
Pete Gaughan and proofreaders Jennifer Campbell, Erika Donald, Nanette Duffy, Laurie
O’Connell, Nancy Riddiough, and Nathan Whiteside helped keep my grammar and spell-
ing on track. Elizabeth Zinkann, the technical editor, scrutinized the text for technical
errors and to be sure it was complete. Nila Nichols, electronic publishing specialist, trans-
formed my plain manuscript into the beautiful book you are now holding. I am grateful
to them all.
Roderick Smith
October 2000
Contents at a Glance
Introduction . . . . . . . . . . . . . . . . . . . . . . . xx
Part 1 How Things Work 1
Chapter 1 An Introduction to SMB/CIFS . . . . . . . . . . . . . . . . . . . . 3
Chapter 2 Integrating SMB/CIFS into Linux . . . . . . . . . . . . . . . . . . .33
Part 2 Essential Configuration 59
Chapter 3 Installing Samba . . . . . . . . . . . . . . . . . . . . . . . .61
Chapter 4 GUI Configuration Tools and the smb.conf File. . . . . . . . . . . . . .87
Chapter 5 Configuring File Sharing . . . . . . . . . . . . . . . . . . . . 125
Chapter 6 Configuring Printer Sharing . . . . . . . . . . . . . . . . . . . 157
Chapter 7 Using Linux as an SMB/CIFS Client . . . . . . . . . . . . . . . . . 195
Part 3 Advanced Configurations 225
Chapter 8 Automation. . . . . . . . . . . . . . . . . . . . . . . . . 227
Chapter 9 Samba as an NBNS Server. . . . . . . . . . . . . . . . . . . . 247
Chapter 10 Configuring Domains . . . . . . . . . . . . . . . . . . . . . 263
Chapter 11 Local and Routed Browsing . . . . . . . . . . . . . . . . . . . 285
Chapter 12 Tuning Samba for Optimum Performance . . . . . . . . . . . . . . 315
Chapter 13 Integrating Samba into a Broader Network . . . . . . . . . . . . . . 349
Part 4 Maintaining a Healthy System 377
Chapter 14 Samba Security Considerations . . . . . . . . . . . . . . . . . . 379
Chapter 15 Managing Accounts . . . . . . . . . . . . . . . . . . . . . . 425
Chapter 16 Backups . . . . . . . . . . . . . . . . . . . . . . . . . . 443
Chapter 17 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . 491
Appendices 523
Appendix A Configuration Reference Guide . . . . . . . . . . . . . . . . . . 525
Appendix B OS-Specific Issues . . . . . . . . . . . . . . . . . . . . . . 557
Appendix C The GNU GPL . . . . . . . . . . . . . . . . . . . . . . . . 593
Index. . . . . . . . . . . . . . . . . . . . . . . . . . 601
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . xx
Part 1 How Things Work 1
Chapter 1 An Introduction to SMB/CIFS . . . . . . . . . . . . 3
Windows Networking and the Development of Samba . . . . 4
The Basic Protocols: NetBIOS, NetBEUI, and SMB . . . . 4
The Evolution of SMB Protocols . . . . . . . . . . 6
The Emergence of Samba . . . . . . . . . . . . 7
SMB/CIFS in Various Environments . . . . . . . . . 8
Integration of TCP/IP and SMB/CIFS . . . . . . . . . . 13
SMB/CIFS Terminology . . . . . . . . . . . . . . 16
Clients, Servers, and Shares . . . . . . . . . . . 16
Workgroups and Domains . . . . . . . . . . . . 17
Network Browsing. . . . . . . . . . . . . . . 20
The Structure of an SMB/CIFS Network . . . . . . . . . 21
Naming of NetBIOS Computers and Networks . . . . . 21
A Named Hierarchy in a Flat Space . . . . . . . . . 22
Resource Types. . . . . . . . . . . . . . . . 24
The Role of PDCs . . . . . . . . . . . . . . . 28
The Role of NBNS Servers . . . . . . . . . . . . 28
NetBIOS Browsing. . . . . . . . . . . . . . . 29
Samba’s Capabilities . . . . . . . . . . . . . . 30
Summary . . . . . . . . . . . . . . . . . . . 32
Chapter 2 Integrating SMB/CIFS into Linux . . . . . . . . . . . 33
SMB/CIFS over TCP/IP . . . . . . . . . . . . . . . 33
TCP/IP vs. NetBEUI as a Transport Protocol . . . . . . 34
Binding SMB/CIFS to TCP/IP in Windows . . . . . . . 36
Linux Features Required for Samba . . . . . . . . . 43
The Samba Daemons . . . . . . . . . . . . . . . 44
Samba 2.0.x . . . . . . . . . . . . . . . . . 45
Samba TNG . . . . . . . . . . . . . . . . . 48
x Contents
Resolving Filesystem Feature Conflicts . . . . . . . . . 50
Filename Length and Case Retention . . . . . . . . 50
FAT-Style File Attributes . . . . . . . . . . . . 51
Ownership and Permission . . . . . . . . . . . 52
Partitions, Mount Points, and Shares . . . . . . . . 56
Summary. . . . . . . . . . . . . . . . . . . 58
Part 2 Essential Configuration 59
Chapter 3 Installing Samba . . . . . . . . . . . . . . . . 61
Obtaining Samba . . . . . . . . . . . . . . . . 61
Samba with Your Linux Distribution . . . . . . . . 62
Updates from Your Linux Distributor . . . . . . . . 64
Getting the Most Up-to-Date Samba . . . . . . . . 65
Installing a Binary Package . . . . . . . . . . . . . 66
Installing an RPM. . . . . . . . . . . . . . . 66
Installing a Debian Package . . . . . . . . . . . 69
Installing a Tarball . . . . . . . . . . . . . . 69
Compiling the Source Code. . . . . . . . . . . . . 70
Compiling a Source RPM . . . . . . . . . . . . 70
Compiling Source from a Tarball . . . . . . . . . 71
Locating Important Files . . . . . . . . . . . . . . 75
Common Installation Directories. . . . . . . . . . 75
Configuration Files . . . . . . . . . . . . . . 76
Running Samba. . . . . . . . . . . . . . . . . 77
Running Samba Manually. . . . . . . . . . . . 78
Common Distribution Startup Scripts . . . . . . . . 80
Running Samba from inetd . . . . . . . . . . . 84
Summary. . . . . . . . . . . . . . . . . . . 86
Chapter 4 GUI Configuration Tools and the smb.conf File . . . . . . 87
Editing smb.conf to Configure Samba . . . . . . . . . 87
Structure of the smb.conf File . . . . . . . . . . 88
Keeping Your Configuration File Readable . . . . . . 93
Testing Your Configuration File . . . . . . . . . . 93
Contents xi
Using Red Hat’s linuxconf to Configure Samba . . . . . . 94
Using linuxconf Locally or Remotely . . . . . . . . 95
A Tour of linuxconf Samba Options . . . . . . . . . 98
Tips Concerning linuxconf Configuration . . . . . . .104
Using SWAT to Configure Samba . . . . . . . . . . .105
Initial SWAT Configuration . . . . . . . . . . . .106
Limiting SWAT Access . . . . . . . . . . . . .107
A Tour of SWAT Options. . . . . . . . . . . . .109
Recommendations for Working with SWAT . . . . . .114
Important General Configuration Options . . . . . . . .115
Server Identification . . . . . . . . . . . . . .115
Logging Options . . . . . . . . . . . . . . .118
An Overview of Security Issues . . . . . . . . . .120
Summary . . . . . . . . . . . . . . . . . . .123
Chapter 5 Configuring File Sharing . . . . . . . . . . . . . .125
Configuring File Shares . . . . . . . . . . . . . .125
A Basic File Share Example. . . . . . . . . . . .126
Home Directory Shares . . . . . . . . . . . . .127
Browsing Options . . . . . . . . . . . . . . .129
Filename Options . . . . . . . . . . . . . . .130
File Locking . . . . . . . . . . . . . . . . .134
Setting Ownership and Permissions . . . . . . . . . .136
Samba Ownership and Permission Options . . . . . .137
Interactions with Other Services . . . . . . . . . .141
Storing FAT-Style File Attributes . . . . . . . . . .142
A Network Security Preview . . . . . . . . . . .144
Some Common File-Sharing Scenarios . . . . . . . . .148
Shared Program and File Server . . . . . . . . . .148
User Files on a High-Security Central Server . . . . . .150
Serving Files to Legacy DOS Systems . . . . . . . .152
Sharing Files Using Multiple Protocols . . . . . . . .154
Summary . . . . . . . . . . . . . . . . . . .156
xii Contents
Chapter 6 Configuring Printer Sharing. . . . . . . . . . . . . 157
Creating Print Queues. . . . . . . . . . . . . . . 158
Ghostscript and PostScript Printing. . . . . . . . . 158
Raw Queues . . . . . . . . . . . . . . . . 166
Fax Queues. . . . . . . . . . . . . . . . . 167
Configuring Printer Shares . . . . . . . . . . . . . 170
A Basic Printer-Sharing Example . . . . . . . . . 170
Sharing All or Some Printers . . . . . . . . . . . 172
Samba Options for Printer Shares . . . . . . . . . 174
Windows Printer Driver Installation. . . . . . . . . 177
Controlling Access to Printers . . . . . . . . . . . . 184
Security Options and Printer Shares . . . . . . . . 185
Interaction of Samba Options with lpd Options . . . . . 186
Some Common Printer-Sharing Scenarios . . . . . . . . 187
Sharing All Local Printers with Variations. . . . . . . 187
Re-Exporting a Remote Printer . . . . . . . . . . 188
Using Samba as a PostScript Processor . . . . . . . 190
Summary. . . . . . . . . . . . . . . . . . . 193
Chapter 7 Using Linux as an SMB/CIFS Client . . . . . . . . . . 195
When to Use Samba as a Client . . . . . . . . . . . 196
Accessing Resources on a Windows Network . . . . . 196
Linux as a Translator . . . . . . . . . . . . . 197
Using Linux Programs on Windows Files. . . . . . . 199
Linux as a Backup Server . . . . . . . . . . . . 200
Using smbclient to Access Remote Files . . . . . . . . 201
Accessing Remote Computers . . . . . . . . . . 201
Transferring Files. . . . . . . . . . . . . . . 205
Manipulating Remote Files . . . . . . . . . . . 207
Mounting Remote Filesystems. . . . . . . . . . . . 208
The Evolution of smbmount . . . . . . . . . . . 209
Mounting Remote Shares . . . . . . . . . . . . 211
Access Quirks of a Mounted Share . . . . . . . . . 214
GUI Browsers . . . . . . . . . . . . . . . . 215
Contents xiii
Printing Files on Remote Printers . . . . . . . . . . .219
Printing a File Using smbclient. . . . . . . . . . .219
Configuring a Linux Printer Queue to Use smbprint. . . .220
Security Implications of smbprint. . . . . . . . . .222
Summary . . . . . . . . . . . . . . . . . . .224
Part 3 Advanced Configurations 225
Chapter 8 Automation . . . . . . . . . . . . . . . . . .227
Uses for Automation . . . . . . . . . . . . . . .228
Dynamically Configuring Samba . . . . . . . . . .228
Dynamically Configuring Windows . . . . . . . . .228
Performing Linux Tasks from Windows. . . . . . . .229
Server-Side Automation . . . . . . . . . . . . . .229
A Review of Variables. . . . . . . . . . . . . .229
Using preexec and postexec . . . . . . . . . . .231
Using Pseudo-Printers . . . . . . . . . . . . .234
Using Magic Scripts . . . . . . . . . . . . . .238
Client Network Scripts . . . . . . . . . . . . . . .238
Basic Domain Controller Configuration . . . . . . . .239
Creating a Logon Script . . . . . . . . . . . . .240
Setting Up Roaming Profiles . . . . . . . . . . .241
Using Roaming Profiles from Windows Clients . . . . .243
Caveats about Logon Scripts and User Profiles . . . . .244
Summary . . . . . . . . . . . . . . . . . . .245
Chapter 9 Samba as an NBNS Server . . . . . . . . . . . . .247
Understanding NBNS . . . . . . . . . . . . . . .248
The Function of NBNS . . . . . . . . . . . . .248
NBNS and DNS. . . . . . . . . . . . . . . .251
NBNS and lmhosts . . . . . . . . . . . . . .252
Setting the Node Type . . . . . . . . . . . . .254
Samba NBNS Operations . . . . . . . . . . . . . .255
Configuring Samba as an NBNS Server. . . . . . . .255
Name Resolution Order . . . . . . . . . . . . .257