It should come as no surprise that the Windows-based vCenter Server no longer receives as many new or updated vSphere features as it once did. Instead, VMware has placed greater emphasis on developing its Linux-based vCenter Server Appliance.
Compared to the Windows-based vCenter Server, the Linux-based vCenter Server Appliance is scalable, cost-effective and comes preconfigured, making it easier to deploy. In this article, I'll explain how to migrate from vCenter Server to the vCenter Server Appliance (vCSA) so you can gain access to new features and a simplified management system.
Considering how complex it is to migrate from one vCenter Server to another, VMware's migration path to the vCSA is surprisingly straightforward. In order to complete the migration, your source must have an integrated VMware Platform Services Controller set up. This migration takes a significant amount of time, so plan ahead for downtime.
The supported migration path is very specific in regard to what supported versions you can migrate to and from; as it currently stands, you can migrate systems to vSphere 6.0. In order to migrate to vSphere 6.5, you must first perform an appliance upgrade from version 6.0 to 6.5. The only configurations the source side supports are vCenter Server versions 5.1 through 5.5 update 3. VMware has yet to release a migration path for vSphere 6.
In order to migrate from vCenter Server to vCSA, you must use the vSphere 6.0 Update 2m Migration Tool. It looks similar to other vCSA deployment webpages with the exception that it only gives you the option to upgrade.
Preconfiguring migration items
There are several items you need to preconfigure prior to running through the wizard. The migration tool needs to run on the Windows vCenter Server in order for the migration to complete successfully. Copy the Migration Assistant folder from install media to an appropriate folder on the Windows vCenter. Do not run the migration wizard from the vCenter, as the vCenter must go through several reboots.
You can find the migration assistant that runs on the Windows vCenter on the root of the migration ISO. Copy the folder Migration Assistant to the Windows vCenter and then double-click the migration assistant executable. When I attempted to do this, I received an error message that read "Invalid Component ID: Migration." This error was the result of the migration assistant using a previous version of the in Client Integration Plug-in. If you have a version of the Client Integration Plug-in that is later or earlier than the shipped version, you must replace it with the plug-in included in the migration install media.
Preparing to migrate to vCenter Server Appliance
Before you can run through the wizard, you need to use remote desktop protocol to connect to vCenter and run the migration assistant executable in the migration folder that you uploaded earlier. This starts a script on the source side. It will then prompt you to provide your single sign-on (SSO) password. Once you do this, the migration assistant executable will start to perform checks and then start a listening service(Figure A).
Open the wizard using Firefox or Chrome and press the Migrate button. If prompted, accept the Client Integration Plug-in and the wizard will start. Accept the VMware End User License Agreement and press Next.
Next, indicate the host to which you want to deploy your appliance. Heed the warnings you receive and make sure your ESXi hosts aren't in lockdown and that Distributed Resource Scheduler is set to manual -- the last thing you want is for the VM to perform a vMotion in the middle of running a script. The wizard may prompt you to accept the ESXi certificate.
The next step is to set up the vCSA's VM settings. The wizard will import all the various settings and configurations, but it won't rename the vCSA. You'll do this manually after the migration is complete. That said, enter the appropriate settings into the VM screen. The OS password is the root password for the device, so make sure you remember it. Click Next.
At this point, enter the details for the Windows vCenter you intend to migrate; this requires your SSO details. If you encounter any errors, check the firewall configuration.
Next, enter your Active Directory (AD) credentials so the appliance can join the same AD domain.
On the next screen, select the appropriate appliance size. This should be based on whatever you had it set to when using the Windows vCenter.
Once this is done, select the appropriate data store -- which should be a shared data store -- for the server, and then click Next.
The final configuration page, shown in Figure C, is where you set up temporary network details for the appliance. Once the migration is complete, the appliance will assume the networking details of the Windows vCenter.
Finally, the wizard will ask whether you wish to join the VMware Customer Experience Improvement Program. Once you respond to this, the migration will begin. The migration will go through several stages and reboots until it is completed. Once migration is complete, the appliance will power up and the Windows vCenter will power off. The completion screen will also provide the URL for the vSphere Web Client.
The setup should look familiar when you log in, as all of the vCenter settings have been carried across to vCSA. You can power up the old appliance and restore the pre-migration setup as a failback position if necessary -- just be sure to power off vCenter Server Appliance first, as it shares an IP with the old version.
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