Step-by-Step: Upgrade VMware vCenter Server Appliance 5.5 to 6.5u1

With the release of VMware 6.5(u1), lot of customers upgrade or migrate their vCenter to 6.5(u1) from older version such as vSphere 5.5 or 6.0. In this topic, I’ll show you how to upgrade VMware vCenter Server Appliance (vCSA) 5.5 to vCSA 6.5. To follow this topic, you need to download the vCSA 6.5(u1) from VMware. Then mount the ISO on a machine. From my side, I have mounted the ISO on my laptop running on Windows 10 1607.

The VMware vCSA upgrade is done in 2 steps:

  • The vCSA deployment
  • The data migration from source to destination

Before beginning you need the following:

  • A new name for the new VM or rename the old vCenter VM Name with _old prefix for example
  • A temporary IP address
  • Enough storage for the appliance
  • Enough compute resources to run the appliance

Step 1: Deploy a new appliance

Once you have mounted the ISO, open <ISO Drive Letter>\vcsa-ui-installer\win32\installer.exe. Then choose Upgrade.

The next screen introduces the steps to follow to upgrade your appliance from vCSA 5.5 or 6.0 to vCSA 6.5u1. Just click on Next.

Once the next screen, just accept the license agreement and lick on Next.

In the next window, specify the vCenter FQDN or IP address and password to connect to. Then specify the ESXi name which hosts the vCenter Appliance. I specify the ESXi instead of the vCenter because I want to upgrade this vCenter server. When the upgrade will occur, the current vCSA will be shutdown.

Then choose the deployment type and click on next.

Then specify an ESXi or vCenter name. Because I migrate the only one vCenter I have, I choose to specify the ESXi name and credentials to connect to.

Next choose a destination VM folder and click on Next.

Then choose an ESXi in the list.

Next specify a VM name and the root password for the target vCSA.

In the next window, regarding your needs, choose the right appliance size. In the table, you have information about supported number of hosts and VMs.

Next choose the datastore where you want to store the vCSA VM file. You can also deploy the appliance in thin provisioning.

Next specify the temporary IP address. This IP is used only during the data migration step.

In the next screen, you can review the settings you apply previously. When you have reviewed the settings just click on Finish to run the vCSA deployment.

Once the appliance deployment is finished, you can click on continue to process the step 2.

Step 2: Migrate configuration for vCSA 5.5 to vCSA 6.5

The next screen introduces the step2 which consists of copying data from source vCenter Server Appliance to the new appliance.

The next step runs some verifications to check if the configuration can be migrated. For example, in the below screenshot is indicated that a plugin cannot be migrated and to check if DRS is not enabled on the ESXi which host the new appliance. If the DRS is enabled, the new appliance can be migrated and so the wizard will be not able to contact this VM anymore (we have specified the ESXi in step 1).

In the screen, the wizard asks you which data you want to migrate.

Then you can choose to join the CEIP or not.

Next you can review the settings before run the data copies. To run the migration, just click on Finish.

Once the migration is finished, you can connect to the vCenter by using the web client and enjoy the new web interface (either flash or html). The source appliance should be shutdown.

About Romain Serre

Romain Serre works in Lyon as a Senior Consultant. He is focused on Microsoft Technology, especially on Hyper-V, System Center, Storage, networking and Cloud OS technology as Microsoft Azure or Azure Stack. He is a MVP and he is certified Microsoft Certified Solution Expert (MCSE Server Infrastructure & Private Cloud), on Hyper-V and on Microsoft Azure (Implementing a Microsoft Azure Solution).


  1. Nice guide Romain! Found your post on the /r/vmware.

  2. Hi Romain,

    Nice guide indeed. Small question though. You mention you connected directly to the ESXi host to deploy the appliance, yet the screenshot shows a datacenter and cluster with multiple hosts.



  3. I went through all of this on my test environment, the problems I’m having is I can’t connect to the web, web client. When trying to connect to port 5840 I get all keep getting invalid server response. please try again.

  4. I’m looking at the 6.5 Update 1g release notes. It is showing the following under “Upgrade Notes for This Release”

    vCenter Server 6.5 Update 1 supports upgrades and migrations from vCenter Server 6.0 Update 3 and above to vCenter Server 6.5 Update 1.

    Has something changed where we can’t go from 5.5U3 to 6.5 U1?
    I was planning to do the migration from the Windows vCenter to the VCSA

  5. Can i use the same vCenter name on the new vCSA ?

  6. Hi,

    Can i upgrade my vCenter Appliance 5.5 w/ Distributed switch to version 6.5 using this method?

  7. Hi Romain. I followed your guide and everything went smooth in upgrade from 5.5u3 to 6.5 ( However now I´m unable to logon to the new vcsa webgui with root as I get the following error:
    “A server error occurred.
    Unable to login because you do not have permission on any vCenter Server systems connected to this client.
    Check the vSphere Web Client server logs for details.”
    I´ve also tried with root@local, root@vsphere.local, admin@local and admin@vsphere.local but the only account which I can logon with and gives me the error is root. Login to VAM with root works fin though. What am I missing?

  8. As I wrote before, I´ve tried all possible login options and administrator@vsphere.local gives me: “Invalid credentials”. Also worth mentioning is that I´ve never used AD integraded auth before, thus only logging in with root.

  9. does it migrate the old certificates as well from windows vCenter to vcsa?

  10. Hello Romain

    Can you contact me?

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