The Team That Wins Together

1
Agenda

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

2
The Interoperability Challenge

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

Agenda

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

Windows Server Message Block (SMB) Common
Internet File System (CIFS)
Unix Systems Network File System (NFS)
Macintosh AppleTalk Filing Protocol (AFP)
NetWare NetWare Core Protocol (NCP)
Today well focus on Unix and Windows Interop
3
Origin of NFS and SMB Protocols

• NFS
• Developed by Sun in the early 1980s
• Licensed free to the industry in 1984
• Quickly became de facto for UNIX file sharing

• SMB
• Developed in early 1980s by Microsoft, IBM,
  Intel, and others
• Early specifications published by X/Open,
  Microsoft and Intel
• Became standard for PC networking

Agenda

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

Incompatibility created the need for
interoperability solutions
4
Common Windows/UNIX Interoperability Solutions
Agenda

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

• 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

5
SMB Solution
Agenda
Standard with OS
SMB software

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

Interfaces Ethernet, FDDI, ATM, Token Ring
Unix Server
SMB
Client for Microsoft Networks (redirector)
PC System
Unix Server
6
PC-NFS Solution
Standard with OS
PC-NFS Software
Agenda

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

Interfaces Ethernet, FDDI, ATM, Token Ring
Unix Server
NFS Server Process
NFS
PC-NFS Client
Client for Microsoft Networks (redirector)
Client for Microsoft Networks (redirector)
PC System
PC System
7
Network Attached Storage Solution
Standard with OS
NAS
Agenda

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

Interfaces Ethernet, FDDI, ATM, Token Ring
Unix Server
NFS Client
NFS
NFS Server
SMB
Client for Microsoft Networks (redirector)
SMB Server
PC System
8
Comparison of SMB NFS Administration
Agenda

• 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

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

9
SMB NFS Protocol Differences
Agenda

• 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

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

10
NetBIOS Protocol
Agenda
Establishing a NetBIOS session is the first step
to making an SMB connection.

• 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

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

11
SMB Protocol Details
Agenda

• 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

12
SMB Authentication Options
Agenda

• 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

13
Proxy Authentication
Agenda

• 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
No user found Domain A---- User logon passed to
trusted Domain B for validation
TRUSTED TRUSTING
SMB server sends Username and password
to Authentication Server
NT Authentication Server Domain A
Authentication Request
SMB Server
Authentication Response
SMB server forwards response to the client
Client Connection Request
Client (SMB/CIFS)
14
ClearCase in a Mixed Environment
Agenda

• Rationals 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

15
ClearCase Capabilities in a Mixed Environment
Agenda

• 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

16
Interoperability Solutions for ClearCase
Agenda

• 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

17
Example Solution using TAS
Agenda
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

TAS Server(ClearCase View Server)
TAS Server(VOB Server)
(VOB)
View
project
bin
src
Version Tree
Meta Data
foo.c
bar.c
NT ClearCase users can access Unix VOB and View
Servers using their native NT environment.
ClearCase
18
Role of TAS in a ClearCase Environment
Agenda
TAS allows NT clients to access Unix VOB and
View storage directories

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

• 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
• \\ltservernamegt\vobstore\vob.vbs

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Configuring TAS
Agenda

• 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

20
Configuring TAS Cont.
Agenda

• Username map
• Map ClearCase service account to appropriate UNIX
  user

• 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, 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

21
Configuring a ClearCase Client
Agenda

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

• 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.

Step-by-step TAS instructions for use with
ClearCase available at http//clearcase.rational.
com/literature/TAS.html
22
ClearCase Region Synchronizer
Agenda
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

• 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\vobs
  tore\john_maestro_test.vbs
• to
  \\fileservice\vobstore\john_maestro_test.vbs

23
Implementation Issues
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

• Introduction to SMB and NFS
• Comparison of SMB and NFS
• SMB - Under the Hood
• ClearCase in a Mixed Environment
• TAS in a ClearCase Environment

24
Questions?