Determining Domain Migration Strategies
Determining Domain Migration Strategies |
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In any planning process it is normal to make and refine important decisions. The choices you make while planning your migration might cause you to defer deployment of some of the system features until a later date. The first steps in creating your migration roadmap are to identify and prioritize your migration goals and to understand the implications of your choices.
In choosing to migrate to Windows 2000, you no doubt have identified certain features and benefits that you are eager to deploy. The following section lists some typical migration goals and explains key concepts and their implications for these goals. After finishing this section, you should have enough information to complete your Migration Project Roadmap.
Your migration planning needs to reflect your primary migration goals. These goals might be business related or they might relate to the migration itself.
In most cases, business-related goals drive the initial migration decision. Examples of such goals are greater scalability and improved security. Business-related goals are involved when making implementation choices, and can be used to evaluate possible tradeoffs. Usually some form of compliance table is prepared, which in later stages is used to identify the technologies and product features to be implemented in the final platform. These technologies and features will help you to achieve your business-related goals.
Migration-related goals could include such concerns as the effect of disruption on production systems, final system performance, and ways to increase mean time between failures. These goals can determine how test plans and acceptance criteria are formulated.
Migration-related goals are not driven by the need to implement specific technical features of Windows 2000 Server; but rather are concerned with the migration process itself. Some migration-related goals are listed in Table 10.1.
Table 10.1 Migration-Related Goals
| Goals | Implications for Migration Process |
|---|---|
| Minimize disruption to the production environment | User access to data, resources, and applications needs to be maintained during and after the migration.
The user's familiar environment needs to be maintained during and after the migration. |
| Maintain system performance | User access to data, resources, and applications needs to be maintained during and after the migration.
The user's familiar environment needs to be maintained during and after the migration |
| Increase mean time between failures | User access to data, resources, and applications needs to be maintained during and after the migration.
The user's familiar environment needs to be maintained during and after the migration |
| Minimize administrative overhead | There needs to be seamless migration of user accounts. |
| If possible, users need to be able to retain their passwords. | |
| Administrators should only have to visit the client computer a minimum number of times. |
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| There needs to be minimal setup of new permissions for resources. | |
| Maximize "quick wins" | The enterprise needs to obtain earliest access to key features of the new platform. |
| Maintain system security | There needs to be minimal impact on security policy. |
To receive maximum benefit from Windows 2000 technologies and fully realize your migration-related goals, it is recommended that you switch your Windows 2000 domains to native mode as soon as possible. However, depending on your existing network configuration, you might not be able to switch to native mode until you have completely eliminated Windows NT backup domain controllers (BDCs) from your domain. For a definition of native mode, see "Determining When to Move to Native Mode" later in this chapter.
Note that you can still deploy Windows 2000 clients and member servers before upgrading the domain infrastructure. See "Upgrading Clients and Servers" later in this chapter.
There are two ways to arrive at your desired infrastructure:
A domain upgrade is the process of upgrading the Primary Domain Controller (PDC) and the BDCs of a Windows NT domain from Windows NT Server to Windows 2000 Server.
A domain restructure is a complete redesign of the domain structure, usually resulting in fewer, larger domains. This choice is for those who are dissatisfied with their current domain structure or who feel that they cannot manage an upgrade without serious impact to their production environment.
Upgrade and restructure are not mutually exclusive; some organizations might upgrade first and then restructure, while others might restructure from the start. Both require careful thought and planning before choices are implemented.
Though the focus of this chapter is domain upgrade and restructure, do not interpret this to mean that you must postpone deployment of Windows 2000 clients and member servers until you have upgraded the domain infrastructure. You can use Windows 2000 clients and servers in your existing Windows NT environment and still gain a number of benefits from the new technologies. Table 10.2 lists some of the benefits gained simply by upgrading clients and servers to Windows 2000.
Table 10.2 Benefits from Simple Client or Server Upgrade
| Benefit | Features |
|---|---|
| Manageability | Plug and Play |
| Hardware wizard with Device Manager | |
| Support for Universal Serial Bus | |
| Microsoft Management Console | |
| New Backup utility | |
| Setup and troubleshooting tools | Automatic application installation allows an administrator to specify a set of applications that are always available to a user or group of users. If a required application is not available when needed, it is automatically installed in the system. |
| File system support | NTFS 5.0 enhancements include support for disk quotas, the ability to defragment directory structures, and compressed network I/O |
| FAT32 | |
| Application services | Win32® Driver Model |
| DirectX® 5.0 | |
| Windows Script Host | |
| Information sharing and publishing | Microsoft Distributed file system (Dfs) for Windows 2000 Server makes it easier for users to find and manage data on the network. |
| Integrated Internet Shell | |
| Print server services | Easier location of printer through Active Directory Printing from the Internet |
| Scalability and availability | Improved Symmetric Multiprocessor support |
| Security | Encrypting File System |