Linux Samba Server Administration (Craig Hunt Linux Library)

652 Pages·2000·4.2 MB·English

by  Roderick W. Smith

Linux Samba Server
Administration
Roderick W. Smith
SYBEX®
Linux Samba Server
Administration
Roderick W. Smith
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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