Migrating a Web Server to IIS 5.0

Choosing an Approach

There are several ways you can approach upgrading an IIS Web server, as summarized in the following paragraphs.

Upgrade to a clean installation. Perform a clean installation of Windows 2000 Server and IIS 5.0 on new hardware, and then migrate settings, content, and applications to the new server by using the IIS Migration Wizard included on the Resource Kit companion CD. Thoroughly test and debug the migrated server prior to deploying it and taking the original production Web server offline.
Pros   By doing this, you avoid taking your production Web server offline for a potentially extended time period while you upgrade and test it. Following deployment, if problems arise with the new server that didn’t appear during testing, you have the original server available as a backup.
Cons   The IIS Migration Wizard will not migrate large numbers of Web sites.
Recommendation   This is the recommended method if you want to upgrade your hardware at the same time you upgrade IIS.
Upgrade a duplicate of the IIS server. On a second computer, install the same version of Windows NT Server and IIS as exists on the current production Web server and replicate content and applications. Upgrade the new server to Windows 2000 Server with IIS 5.0 by using the Windows 2000 Server Setup Wizard. Install IIS 5.0 during setup. Thoroughly test and debug the migrated server prior to deploying it and taking the original production Web server offline.
Pros: By doing this, you avoid taking your production Web server offline for a potentially extended time period. Following deployment, if problems arise with the new server that didn’t appear during testing, you have the original server available as a backup.
Cons: You could potentially run into problems with the upgrade if the new server hardware is quite different from the old one. You’ll probably need to adjust performance settings that are affected by hardware.
Recommendation: This is a good approach if you want to upgrade your existing hardware.
Upgrade a mirror of the production IIS server. Mirror the current production IIS server (operating system, software, configuration settings, and content) to a second computer. Then upgrade the mirror to Windows 2000 Server with IIS 5.0 by using the Setup Wizard. Thoroughly test the upgraded server prior to deploying it and taking the original production Web server offline. (You might be able to use Iissync.exe to replicate configuration settings. For more information about using this tool, see the topic “Replication and Clustering in IIS” in the IIS 5.0 online product documentation.)
Pros: By doing this, you avoid taking your production Web server offline for a potentially extended time period. Following deployment, if problems arise with the new server that didn’t appear during testing, you have the original server available as a backup.
Cons: All hardware on the second system must exactly duplicate the original IIS server, so you must forgo the option to upgrade your hardware when you upgrade IIS.
Recommendation: This is an acceptable approach if you don’t want to upgrade your hardware.
Upgrade the production IIS server. Take your existing IIS production Web server offline, and then upgrade it to Windows 2000 Server with IIS 5.0 by using the Setup Wizard. Thoroughly test the upgraded server prior to re-deploying it.
Pros: No hardware cost.
Cons: Upgrading a production Web server is extremely risky. You must take the server offline, and it will not be available to users until you complete all upgrade tasks, testing, and debugging.
Recommendation: This method is not recommended except when you have implemented a Web server cluster and only need to take one of the clustered production Web servers offline at a time to implement the upgrade. The remaining servers in the cluster stay online and are fully functional.