Lesson 3: Upgrading Domain Controllers and Member Servers

In Windows NT 4.0, the PDC and the BDCs authenticate domain logons and maintain the directory database for the domain. You upgrade domain controllers and member servers running previous versions of Windows NT to either Windows 2000 Server or Windows 2000 Advanced Server. Once you upgrade all of your domain controllers to Windows 2000, you can take full advantage of the enhanced administrative features offered in Windows 2000 by switching the domain from mixed mode to native mode. This allows the domain to fully use the new features of Active Directory directory services.

You upgrade domain controllers and member servers running previous versions of Windows NT to either Windows 2000 Server or Windows 2000 Advanced Server. Table 13.1 lists the upgrade paths for server operating systems.

Table 13.1 Windows 2000 Upgrade Paths for Member Servers

Upgrade from	Upgrade to
PDC or BDC running Windows NT Server 3.51 or 4.0	Domain controller, Windows 2000 Server, or Windows 2000 Advanced Server.
Member server running Windows NT Server 3.51 or 4.0	Windows 2000 Server or Windows 2000 Advanced Server. After the upgrade, you can change it to a domain controller if required.
Windows NT Advanced Server 3.1, Windows NT Server version 3.5	Windows NT Server, version 3.51 or 4.0 first, then upgrade to Windows 2000 Server or Windows 2000 Advanced Server.

In Windows 2000 networks, all domain controllers running Windows 2000 have equal status in the domain. When you upgrade Windows NT 4.0 or 3.51 PDCs and BDCs to Windows 2000, there is no longer a distinction between PDCs and BDCs. Instead, they become peer domain controllers.

You also upgrade member servers running Windows NT Server 3.51 and 4.0 to Windows 2000. This allows them to take advantage of Active Directory directory services. You can promote these member servers to domain controllers as necessary.

Before you start the upgrade process, there are a couple of things you need to do to prepare to upgrade your domain controllers and member servers. First of all, make sure that all your computers meet the minimum hardware requirements for Windows 2000 Server and Advanced Server. Then prepare a rollback strategy in case there are any upgrade problems. Finally prepare the domain controllers and member servers for the upgrade.

Before you upgrade a domain controller or a member server to Windows 2000, make sure that the computers on the network meet the minimum hardware requirements. Table 13.2 describes the hardware requirements.

Table 13.2 Windows 2000 Server Minimum Hardware Requirements

Hardware	Minimum requirements
Processor	Intel Pentium 166 MHz or higher Compaq Alpha AXP
Memory	Pentium-based: 64 MB for member servers, 128 MB or higher for domain controllers
Compaq	Alpha-based: 96 MB for member servers, or 128 or higher for domain controllers
Hard Disk	Up to 1.2 GB of free space on the boot partition, depending upon the file system, and 6 MB of free space on the system partition.
Video	VGA or higher video card and monitor.
Other Components	Compact disc installation: CD-ROM or DVD-ROM drive.
Networking	Network adapter card and related cables.
Accessories	Keyboard and mouse or other pointing device.

To create a rollback strategy, preserve one BDC with the current directory database. To do this, synchronize a BDC with the PDC, and then take the fully synchronized BDC offline. Keep this BDC available until you are certain the upgrade is successful. If problems occur during the upgrade, you can reinstate the offline BDC, promote it to a PDC, and recover your system state.

There are some steps you should do to prepare your domain controllers and member servers to be upgraded. Before you start the Windows 2000 Setup wizard, you should do the following:

1. Remove any virus scanners, third-party network service, or client software. Read the Release Notes file (Relnotes on the Windows 2000 CD-ROM) for information about any known problems with specific applications.
2. Disconnect the serial cable that connects an uninterruptible power supply (UPS) device. During setup, Windows 2000 attempts to detect devices connected to serial ports, which can cause problems with UPS equipment.
3. If your system contains Industry Standard Architecture (ISA) devices that are non-Plug and Play, set your system basic input/output system (BIOS) to reserve all interrupt requests (IRQs) currently in use by non-Plug and Play ISA devices. Failure to do so might result in the error message INACCESSABLE_BOOT_DEVICE. In some cases, the non-Plug and Play ISA devices might not function.

You upgrade the PDC to Windows 2000 first, and then use the Active Directory Installation wizard to configure the new domain.

To complete the domain controller upgrade process, you would do the following:

1. If you are upgrading from a CD-ROM, insert the Windows 2000 CD-ROM into the CD-ROM drive. The Windows 2000 Setup wizard starts automatically.

If you are upgrading from the network, run Winnt32.exe, which is located in the shared folder that contains the Windows 2000 installation files.

2. The setup program upgrades the operating system.
3. The computer reboots and automatically logs on as Administrator.
4. The Active Directory Installation wizard automatically runs.
5. Configure the new domain using the guidelines explained below.

When the setup program finishes, the computer restarts and Windows 2000 automatically logs on as Administrator. The Active Directory Installation wizard (Dcpromo.exe) starts and helps you to configure the new domain environment and to migrate user, group, and computer accounts to Active Directory directory services.

To use the Active Directory Installation wizard to configure the new domain environment, follow the on-screen instructions. When prompted, select the appropriate configuration options.

Table 13.3 describes the configuration options in the Active Directory Installation wizard when configuring a domain environment:

Table 13.3 Windows 2000 Upgrade Paths for Member Servers

Select this option	If you are upgrading
Domain Controller For A New domain	A PDC. This option creates a new Windows 2000 domain.
Create A New Domain Tree or Create A New Child Domain In An Existing Domain Tree	A PDC in the first Windows 2000 domain in a tree. A PDC in a new domain in an existing tree
Create A New Forest Of Domain Trees or Place This New Domain Tree In An Existing Forest	A PDC in a new domain in an existing tree. A PDC in a new domain tree in an existing forest. This option enables users to access resources in the other trees.

In this practice, you upgrade a computer running Windows NT 4.0 server that is configured as a Primary Domain Controller (PDC) to Windows 2000 Server using a CD-ROM. You install Active Directory directory services, create a new Windows 2000 domain, and install DNS on this computer. You will then use the Active Directory Users and Computers snap-in to view your domain controller.

1. Log on to the PDC as Administrator.
2. Insert the Windows 2000 Server CD-ROM into the CD-ROM drive.

A Microsoft Windows 2000 CD message box appears indicating that the CD-ROM contains a newer version of Windows than the one you are presently running and asks if you would like to upgrade to Windows 2000.

3. Click Yes to begin the upgrade.

Setup displays the Welcome To The Windows 2000 Setup Wizard screen.

4. Ensure that Upgrade To Windows 2000 (Recommended) is selected, and then click Next to continue.

Setup displays the License Agreement screen.

5. Read the license agreement, click I Accept This Agreement, and then click Next to agree with the licensing terms.

The Upgrading To The Windows 2000 NTFS File System dialog box appears asking you if you want Setup to upgrade the drive to NTFS.

6. Click Yes, Upgrade My Drive, and then click Next.

The Report System Compatibility screen appears and lists any items found that are not compatible with Windows 2000.

7. Review the information provided on the Report System Compatibility screen, and then click Next.

Setup copies some installation files and then restarts the computer.

Setup loads some additional files, and then Windows 2000 starts.

Setup copies files to the Windows 2000 installation folders. This may take several minutes.

Setup initializes your Windows 2000 configuration and then restarts the computer a second time.

Setup detects and installs devices on the computer. This may take several minutes.

Setup installs the Networking components.

Setup installs the Windows 2000 components.

Setup performs the final tasks: Installing Start menu items, Registers components, Saves Settings, and Removes any temporary files used.

Setup restarts your computer. The Welcome To The Active Directory Installation wizard appears.

1. On the Welcome To The Active Directory Installation Wizard screen, click Next.

The Create Tree Or Child Domain page appears.

2. Ensure that Create A New Domain Tree is selected, and then click Next.

The Create Or Join Forest page appears.

3. Ensure that Create A New Forest Of Domain Trees is selected, and then click Next.

The Install Or Configure DNS page appears.

4. Ensure that No, Just Install And Configure DNS On This Computer is selected, and then click Next.

The New Domain Name page appears.

5. In the Full DNS Name For New Domain box type domain.com and then click Next.

Setup displays the Database And Log Locations page.

6. Ensure that C:\Winnt\NTDS is in both the Database Location box and the Log Location box, and then click Next.

The Shared System Volume page appears.

7. Ensure that C:\Winnt\SYSVOL is in the Folder Location box, and then click Next.

The Permissions page appears.

8. Click to select Permissions Compatible Only With Windows 2000 Servers, and then click Next.

The Directory Services Restore Mode Administrator Password page appears. This allows you to specify a password for this server's Administrator account.

9. Type password in the Password and Confirm Password boxes.

The Summary page appears.

10. Review the information contained on the summary page, and then click Next to continue.

The wizard installs and configures DNS and Active Directory. This may take several minutes.

11. When the Completing The Active Directory Installation Wizard page appears, read the information on The Active Directory Installation page, remove the CD-ROM from the CD-ROM drive, and then click Finish.

An Active Directory Installation Wizard message box appears indicating that Windows must be restarted before the changes made by the Active Directory Installation Wizard take effect.

12. Click Restart Now.

The computer restarts.

1. Log on to the domain controller as Administrator with a password of password.

The Microsoft Windows 2000 Configure Your Server screen appears.

2. Close the Microsoft Windows 2000 Configure Your Server window.
3. Click Start, point to Programs, point to Administrative Tools, and then click Active Directory Users And Computers.

The Active Directory Users And Computers window appears.

4. Expand domain.com.

5. In the console tree, click Domain Controllers.

Notice that Server1 appears in the details pane.

6. Close the Active Directory Users And Computers window.

After you upgrade the PDC for the domain to Windows 2000, you upgrade the BDCs to Windows 2000. You use the same process to upgrade BDCs as you do to upgrade PDCs. Start the Windows 2000 Setup wizard to begin the installation process. Follow the onscreen instructions to complete the upgrade.

After the operating system upgrade is complete, the Active Directory Installation wizard runs to allow you to configure the domain. To complete the upgrade, select the Additional Domain Controller In Existing Domain option in the Active Directory Installation wizard. This adds the upgraded computer to the existing domain as a domain controller.

When you upgrade a BDC, you must ensure that the system clock on the BDC is synchronized with the system clock on the domain controllers in your network. The Active Directory Installation wizard prompts you for an administrative username and password that is used to add the additional domain controller to the domain. If the difference in the system clocks is too great, the user account you specify will not be accepted, and you will be unable to join the domain.

After you upgrade all domain controllers on your network, you switch the domain from mixed mode to native mode. This allows the network to take full advantage of Windows 2000 functionality.

When you first create a domain, the domain runs in mixed mode. A mixed mode domain enables Windows 2000 domain controllers to interact with other domain controllers that are running versions of Windows NT Server. Domain controllers running versions of Windows NT are referred to as downlevel domain controllers.

In mixed mode

• The domain still uses the upgraded PDC as the domain master for replication with BDCs running Windows NT Server 3.51 or 4.0.
• Computers upgraded from Windows NT Workstation 4.0 or Windows NT Server 4.0 continue to use Windows NT 4.0 system policy.
• Group functionality new to Windows 2000 Server, such as the ability to nest groups, is not available.

After you upgrade all the domain controllers, and if you do not plan to add any additional downlevel domain controllers to the domain, you can switch the domain to native mode. A native mode domain contains only Windows 2000 Server domain controllers.

In native mode

• The PDC is no longer the domain master for replication. Instead, all domain controllers replicate with each other as peers.
• Windows NT Server 3.51 or 4.0 domain controllers cannot function in a native Windows 2000 domain.
• Computers upgraded from Windows NT Workstation 4.0 or Windows NT Server 4.0 use Windows 2000 group policy instead of Windows NT 4.0 system policy.
• Group functionality new to Windows 2000 becomes available.

To switch domain controllers from mixed to native mode, you would do the following:

1. Click Start, point to Programs, point to Administrative Tools, and then click Active Directory Domains And Trusts.
2. Expand your domain and then open the properties for your_domain.
3. On the General page, click Change Mode.

The Active Directory Service displays a warning stating that once you change the domain mode to native mode, you cannot change back to mixed mode.

4. Click Yes, and then click OK to close the properties page for your_domain.

You can upgrade your member servers to Windows 2000 before, during, or after the domain upgrade process. In addition, you can promote member servers to domain controllers after the operating system upgrade, as necessary.

To upgrade the member server to Windows 2000, insert the CD-ROM and follow the on-screen instructions to complete the upgrade. After the upgrade, the member server will still be a member of its domain or workgroup. During an upgrade, local user and group accounts are stored in the registry of the member server and do not get moved to Active Directory directory services.

To promote a member server to a domain controller, run Dcpromo.exe after upgrading to Windows 2000.

When you promote the domain controller, local user and group accounts on the member server are moved to Active Directory directory services. This maintains the permissions previously assigned to resources on that server.

You upgrade domain controllers and member servers running previous versions of Windows NT to either Windows 2000 Server or Windows 2000 Advanced Server. All domain controllers running Windows 2000 have equal status in the domain. When you upgrade Windows NT 4.0 or 3.51 PDCs and BDCs to Windows 2000, there is no longer a distinction between PDCs and BDCs. Instead, they become peer domain controllers.

You also upgrade member servers running Windows NT Server 3.51 and 4.0 to Windows 2000. This allows them to take advantage of Active Directory directory services. You can promote these member servers to domain controllers as necessary.

Before you start the upgrade process, make sure that all your computers meet the minimum hardware requirements for Windows 2000 Server and Advanced Server. You should also prepare a rollback strategy in case there are any upgrade problems and prepare the domain controllers and member servers for the upgrade.

After you upgrade all domain controllers on your network, you switch the domain from mixed mode to native mode. This allows the network to take full advantage of Windows 2000 functionality. When you first create a domain, the domain runs in mixed mode. A mixed mode domain enables Windows 2000 domain controllers to interact with other domain controllers that are running versions of Windows NT Server.