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 Systems Network File System (NFS) Windows Server Message Block (SMB) Common Internet File System (CIFS) NetWare NetWare Core Protocol (NCP) Macintosh AppleTalk 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 Server Interfaces Ethernet, FDDI, ATM, Token Ring Standard with OS SMB software PC System Client for Microsoft Networks (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 IP NetBEUI SMB NetBIOS Unix Server SMB

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

7 Network Attached Storage Solution Standard with OSNAS 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 Server Interfaces Ethernet, FDDI, ATM, Token Ring NFS Client TCP UDP IP NFS Client for Microsoft Networks (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 Username and password to Authentication Server SMB server forwards response to the client Proxy Authentication Client Connection Request Authentication Request Authentication Response Authentication Response SMB Server Client (SMB/CIFS) TRUSTED & TRUSTING Authentication 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) Version Tree Meta Data Unix Workstation ClearCase NT ClearCase users can access Unix VOB and View Servers using their native NT environment. TAS Server (ClearCase View Server) bin src foo.c bar.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 –\\ \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_albdUNIX, 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:  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 ClearCase Region 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

24 Questions?