1

SMB and NFS Protocol

Architecture and

Administration

SMB and NFS Protocol

Architecture and

Administration

Rob Bradbury, Sales Engineer

September 26, 2000

Introduction to

SMB and NFS

Comparison of

SMB and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

2

Enterprises contain heterogeneous systems that use different protocols for remote file system access.

The Interoperability Challenge

Unix SystemsNetwork File System (NFS)

WindowsServer Message Block (SMB)

Common Internet File System (CIFS)

NetWareNetWare Core Protocol (NCP)

MacintoshAppleTalk Filing Protocol (AFP)

Today we’ll focus on Unix and Windows Interop

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

3

Origin of NFS and SMB Protocols

NFS

Developed by Sun in

the early 1980’s

Licensed free to the

industry in 1984

Quickly became de

facto for UNIX file

sharing

SMB

Developed in early 1980’s

by Microsoft, IBM, Intel,

and others

Early specifications

published by X/Open,

Microsoft and Intel

Became standard for PC

networking

Incompatibility created the need for interoperability solutions

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

4

SMB (CIFS) servers running on Unix- Syntax TotalNET Advanced Server, Samba

NFS client software installed on PC systems

- Hummingbird NFS Maestro, Intergraph DiskAccess,

MS Windows Services for Unix NFS Client,

and many more

Multi-protocol network attached storage (NAS)

- MetaStor, EMC, Network Appliance, Auspex

Common Windows/UNIX Interoperability Solutions

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

5

SMB Solution

Unix ServerInterfaces

Ethernet, FDDI,ATM, Token Ring

Standard with OS SMB software

PC System

Client forMicrosoftNetworks

(redirector)

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

TCP UDP

IP

NetBEUI

SMB

NetBIOS

Agenda

TCP UDP

IP

TCP UDP

IP

TCP UDP

IPNetBEUI

SMB

NetBIOS

Unix Server

SMB

6

Client forMicrosoftNetworks

(redirector)

PC-NFS Solution

Unix Server

InterfacesEthernet, FDDI,

ATM, Token Ring

Standard with OS

PC System

PC-NFS Software

NFS ServerProcess

PC System

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Client forMicrosoftNetworks

(redirector)

TCP UDP

IP

NFS

PC-NFSClient

NFS

TCP UDP

IP

NFS

Agenda

TCP UDP

IP

7

Network Attached Storage Solution

Standard with OS NAS

PC System

SMB Server

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Unix ServerInterfaces

Ethernet, FDDI,ATM, Token Ring

NFS Client

TCP UDP

IP

NFS

Client forMicrosoftNetworks

(redirector)

NFS

SMB

NFS Server

Agenda

TCP UDP

IP

8

Comparison of SMB & NFS Administration

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

NFS

Client installation

Uses PC resources

More transparent to Unix

system administrators

PCs can access NFS &

SMB servers

SMB

Server centric

Uses server resources

More transparent to

users/PC applications

PCs can only access

SMB servers

Agenda

9

SMB & NFS Protocol Differences

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

NFS

Stateless protocol

Synchronous writes

Authentication

external to protocol

Network Lock

Manager

SMB

Stateful protocol

Asynchronous writes

Authentication mechanism

built-in to protocol

Locking built-in - native

PC locking

Agenda

10

NetBIOS Protocol

NetBIOS (Network Basic Input/Output System)– Protocol that establishes names and maintains sessions– Specified in RFCs 1001/1002– Uses well know ports 137, 138, 139

NetBIOS name resolution methods– WINS server– lmhosts file– subnet broadcasts– DNS

Establishing a NetBIOS session is the first step to making an SMB connection.

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

11

SMB Protocol Details

SMBnegprot (Negotiate)

– always the first SMB packet

– Negotiates SMB dialect (NT LM 0.12 is

latest)

– Server returns security level

SMBsessetup (Session Setup)

– user is authenticated

SMBtcon (Tree Connect)

– Connect to a device - file service, print

spooler, IPC

SMBopen, SMBread, SMBwrite,…

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

12

SMB Authentication Options

User mode authentication

– local authentication encrypted clear text

– proxy authentication user/password is forwarded to 3rd party system

(generally NT PDC)

Share mode

– users connect with a common password

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

13

NT Authentication Server

Domain A

No user found Domain A----User logon passed to trusted

Domain B for validation

SMB server sends Usernameand password to

Authentication Server

SMB server forwards

response to the client

Proxy Authentication

Client ConnectionRequest

AuthenticationRequest

AuthenticationResponse

AuthenticationResponse

SMB Server

Client (SMB/CIFS)

TRUSTED &TRUSTINGAuthentication Response

from B to A

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

NT Authentication Server

Domain B

Agenda

14

ClearCase in a Mixed Environment

Rational’s recommendations for when to use

ClearCase in a mixed environment.

Windows and Unix developers work on the same

source code

A group of developers maintains code base for Unix

and Windows

Windows developers work primarily on separate

source code but keep VOB on Unix for administrative

purposes

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

15

ClearCase Capabilities in a Mixed Environment

Makes Unix VOB/View Server available to your

NT users

Allows Unix and NT users to access the same

VOBs

Allows Unix and NT users to access the same

Views

Provides a secure and reliable repository for the

common source code

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

16

Interoperability Solutions for ClearCase

Rational certified solutions for ClearCase Interop

SMB servers– Syntax TotalNET Advanced Server

PC-NFS – Intergraph DiskAccess– Hummingbird NFS Maestro – Microsoft Windows NT Services for UNIX Client for NFS Products (SFU)

Network Attached Storage– Not supported in an interop environment

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

17

TAS Server(VOB Server)

NT

(VOB)

VersionTree

Meta Data

Unix WorkstationClearCase

NT ClearCase users can access Unix VOB and View Servers using their native NT environment.

TAS Server(ClearCase View Server)

bin src

foo.cbar.c

project

View

Example Solution using TAS

Install TAS on every VOB/View Server Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

18

Role of TAS in a ClearCase Environment

TAS allows NT clients to access Unix VOB and View storage directories

Do this using TAS volumes

TAS volume - short name for a directory path in

the Unix file system

Example:

– TAS volume “vobstore” refers to the VOB

storage directory - /export/vobstore

Clients access using UNC path name

– \\<servername>\vobstore\vob.vbs

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

19

Configuring TAS

Volume Configuration Provide path to VOB/View storage directories

– Example: /ccstore/vobstore, /ccstore/viewstore

Set umask to 002 Set Filename Case to Preserve Disable oplocks

– Oplocks (opportunistic locks) are an SMB protocol performance enhancement. A client holding an exclusive oplock on a given file can read or write to a local cache instead of having to commit all changes to the server through the network.

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

20

Configuring TAS Cont.

Username map Map ClearCase service account to appropriate

UNIX user

NT, clearcase_albd UNIX, vobadmin

Authentication Configure TAS to use NT PDC as proxy

– minimizes maintenance Can also use local authentication

– Must add users to TAS password file

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

21

Configuring a ClearCase Client

Step-by-step TAS instructions for use with ClearCase available at:

http://clearcase.rational.com/literature/TAS.html

MVFS performance settings

– Set Maximum number of mnodes to keep on

the free list and and Maximum number of

mnodes to keep for cleartext free list to 800.

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

22

ClearCaseRegion Synchronizer

Use the UNC path and not the NFS path!

The region synchronizer

automatically shows the

NFS path found in the registry.

This path has to be changed!

Change the path from: \\fileservice\export\vobstore\john_maestro_test.vbs

to: \\fileservice\vobstore\john_maestro_test.vbs

Makes Unix VOBs/Views accessible to Windows

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

23

Implementation Issues

Introduction to SMB

and NFS

Comparison of SMB

and NFS

SMB - Under the

Hood

ClearCase in a

Mixed Environment

TAS in a ClearCase

Environment

Agenda

Watch for conflicts between PC-NFS and SMB

redirectors

check network access order

UNIX and NT usernames and primary group

must match

check with credmap utility

Set VOB/View permissions correctly

Synchronize paths for VOBs/Views using UNC

names

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Questions?