Chapter 31. Migration from NT4 PDC to Samba-3 PDC

In the IT world there is often a saying that all problems are encountered because of poor planning. The corollary to this saying is that not all problems can be anticipated and planned for. Then again, good planning will anticipate most show stopper type situations. @@ -9,7 +10,7 @@ and planned for. Then again, good planning will anticipate most show stopper typ Those wishing to migrate from MS Windows NT4 domain control to a Samba-3 domain control environment would do well to develop a detailed migration plan. So here are a few pointers to help migration get under way. -

Objectives

The key objective for most organisations will be to make the migration from MS Windows NT4 to Samba-3 domain control as painless as possible. One of the challenges you may experience in your migration process may well be one of convincing management that the new environment @@ -36,7 +37,7 @@ Before migrating a network from MS Windows NT4 to Samba-3 it is vital that all n considered. Users should be educated about changes they may experience so that the change will be a welcome one and not become an obstacle to the work they need to do. The following are some of the factors that will go into a successful migration: -

Domain Layout

Samba-3 can be configured as a domain controller, a back-up domain controller (probably best called a secondary controller), a domain member, or as a stand-alone server. The Windows network security domain context should be sized and scoped before implementation. Particular attention needs to be @@ -57,7 +58,7 @@ designed to serve multiple routed network segments may result in severe performa response time (eg: ping timing) between the remote segment and the PDC is more than 100 ms. In situations where the delay is too long it is highly recommended to locate a backup controller (BDC) to serve as the local authentication and access control server. -

Server Share and Directory Layout

There are few cardinal rules to effective network design that can be broken with impunity. The most important rule of effective network management is that simplicity is king in every well controlled network. Every part of the infrastructure must be managed, the more complex @@ -82,7 +83,7 @@ complex mess that has been inherited. Remember, apparent job security through co and implementation may ultimately cause loss of operations and downtime to users as the new administrator learns to untangle your web. Keep access controls simple and effective and make sure that users will never be interrupted by the stupidity of complexity. -

Logon Scripts

Please refer to the section of this document on Advanced Network Administration for information regarding the network logon script options for Samba-3. Logon scripts can help to ensure that all users gain share and printer connections they need. @@ -96,20 +97,20 @@ Some sites prefer to use a tool such as kixstart to estab user environment. In any case you may wish to do a google search for logon script process controls. In particular, you may wish to explore the use of the Microsoft knowledgebase article KB189105 that deals with how to add printers without user intervention via the logon script process. -

Profile Migration/Creation

User and Group Profiles may be migrated using the tools described in the section titled Desktop Profile Management.

Profiles may also be managed using the Samba-3 tool profiles. This tool allows the MS Windows NT style security identifiers (SIDs) that are stored inside the profile NTuser.DAT file to be changed to the SID of the Samba-3 domain. -

User and Group Accounts

It is possible to migrate all account settings from an MS Windows NT4 domain to Samba-3. Before attempting to migrate user and group accounts it is STRONGLY advised to create in Samba-3 the groups that are present on the MS Windows NT4 domain AND to connect these to suitable Unix/Linux groups. Following this simple advice will mean that all user and group attributes should migrate painlessly. -

Steps In Migration Process

The approximate migration process is described below.

You will have an NT4 PDC that has the users, groups, policies and profiles to be migrated @@ -118,11 +119,11 @@ Samba-3 set up as a DC with netlogon share, profile share, etc.

Procedure 31.1. The Account Migration Process

Create a BDC account for the samba server using NT Server Manager
1. Samba must NOT be running
rpcclient NT4PDC -U Administrator%passwd
1. lsaquery
2. Note the SID returned
net getsid -S NT4PDC -w DOMNAME -U Administrator%passwd
1. Note the SID
net getlocalsid
1. Note the SID, now check that all three SIDS reported are the same!
net rpc join -S NT4PDC -w DOMNAME -U Administrator%passwd
net rpc vampire -S NT4PDC -U administrator%passwd
pdbedit -L
1. Note - did the users migrate?
initGrps.sh DOMNAME
net groupmap list
1. Now check that all groups are recognised
net rpc vampire -S NT4PDC -U administrator%passwd
pdbedit -Lv
1. Note - check that all group membership has been migrated

Now it is time to migrate all the profiles, then migrate all policy files. More later. -

Migration Options

Based on feedback from many sites as well as from actual installation and maintenance experience sites that wish to migrate from MS Windows NT4 Domain Control to a Samba based solution fit into three basic categories. -

Table 31.1. The 3 Major Site Types

Number of Users	Description
< 50	Want simple conversion with NO pain
50 - 250	Want new features, can manage some in-house complexity
> 250	Solution/Implementation MUST scale well, complex needs. Cross departmental decision process. Local expertise in most areas

Planning for Success

Table 31.1. The 3 Major Site Types

Number of Users	Description
< 50	Want simple conversion with NO pain
50 - 250	Want new features, can manage some in-house complexity
> 250	Solution/Implementation MUST scale well, complex needs. Cross departmental decision process. Local expertise in most areas

Planning for Success

There are three basic choices for sites that intend to migrate from MS Windows NT4 to Samba-3.

@@ -141,7 +142,7 @@ No matter what choice you make, the following rules will minimise down-stream pr Test ALL assumptions
Test full roll-out program, including workstation deployment -

Table 31.2. Nature of the Conversion Choices

Simple	Upgraded	Redesign
Make use of minimal OS specific features	Translate NT4 features to new host OS features	Decide:
Suck all accounts from NT4 into Samba-3	Copy and improve:	Authentication Regime (database location and access)
Make least number of operational changes	Make progressive improvements	Desktop Management Methods
Take least amount of time to migrate	Minimise user impact	Better Control of Desktops / Users
Live versus Isolated Conversion	Maximise functionality	Identify Needs for: Manageability, Scalability, Security, Availability
Integrate Samba-3 then migrate while users are active, then Change of control (ie: swap out)	Take advantage of lower maintenance opportunity

Samba Implementation Choices

Table 31.2. Nature of the Conversion Choices

Simple	Upgraded	Redesign
Make use of minimal OS specific features	Translate NT4 features to new host OS features	Decide:
Suck all accounts from NT4 into Samba-3	Copy and improve:	Authentication Regime (database location and access)
Make least number of operational changes	Make progressive improvements	Desktop Management Methods
Take least amount of time to migrate	Minimise user impact	Better Control of Desktops / Users
Live versus Isolated Conversion	Maximise functionality	Identify Needs for: Manageability, Scalability, Security, Availability
Integrate Samba-3 then migrate while users are active, then Change of control (ie: swap out)	Take advantage of lower maintenance opportunity

Samba Implementation Choices

 Authentication database back end
 	Winbind (external Samba or NT4/200x server)
 	Can use pam_mkhomedir.so to auto-create home dirs
@@ -198,5 +199,5 @@ Migration Tools
 
 Authentication
 	New SAM back end (smbpasswd, tdbsam, ldapsam, mysqlsam)
-

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