In this second part of the blog series “Upgrading to vSphere 6.7 Update 1, and Using the vCenter Converge Tool”, I will go over my experience using the Convergence tool. Lets get started.
The Basics of the vCenter Converge Tool
David Stamen (@davidstamen) put together an excellent blog on Understanding the vCenter Server Converge Tool, at VMware’s offical blog site, which I found very useful. Shout-out to Nigel Hickey (@vCenterNerd) for answering some questions I had.
The Convergence Tool basically takes the external PSC and embeds it into the vCenter appliance like so:
For this customer, I had three vCSA’s and three PSC’s that I needed to converge. Most of the blogs that I found didn’t cover PSC’s that were joined to a domain, environments with multiple vCenters, or with multiple PSC’s, so I thought I would write this up in a blog.
Planning the Convergence
The first thing I had to do was take note of any registered services with the SSO domain. I utilized VMware’s KB2043509 to identify these services, which I had none to worry about. VMware specifically calls out NSX and Site Recovery Manager (SRM), but since those were not in use at this customer, the only things I had to worry about were Horizon, vROps, vRLi and Zerto. Each of these services registered directly to the vCenters, so I had nothing to worry about there. If I had any services registered with the SSO domain, I’d simply need to re-register them once the convergence tool was ran. But since this didn’t apply, I can move forward with configuring the scripts for the convergence tool.
I also need to have an understanding of the replication typology of the existing SSO domain. VMware KB2127057 was an excellent resource I used to gather that information. Opening a putting session to a vCenter, and running the ‘vdcrepadmin’ command against each of the external PSCs, I was able to see the following:
# cd /usr/lib/vmware-vmdir/bin
./vdcrepadmin -f showpartners -h external_psc-a.domain.com -u administrator -w kjdshfsdkjfhskjdhf
./vdcrepadmin -f showpartners -h external_psc-b.domain.com -u administrator -w kjdshfsdkjfhskjdhf
./vdcrepadmin -f showpartners -h external_psc-c.domain.com -u administrator -w kjdshfsdkjfhskjdhf
I can see they already have a ring topology, which is the desired architecture. If I were to draw the SSO typology out, it would look something like:
Setting Up the JSON Templates for the Convergence Tool
The converge.json template that the convergence tool uses, can be found in the VMware VCSA ISO, that was used for the 6.7 Update 1 upgrade, under the following path: DVD Drive (#):\VMware VCSA\vcsa-converge-cli\templates\
To make my life easier, I copied the contents of the entire ISO to a folder on the root of my C drive. I then made a seperate folder on the root of C called converge, and created a folder for each of the three vCenters I’d be working with: vCenter-A, vCenter-B, vCenter-C. I made a copy of the converge.json, and placed it into each folder.
Taking a look at the converge.json for vCenter-A, the template tells you what data needs to be filled in, so pay close attention. Lines 10 – 15 needs entries for the ESXi host where the vCenter resides, or the managing vCenter appliance. Here I chose the option to used the Managing ESXi host. All I needed to do, was look in vSphere to see where the vCSA appliance VM resided on which host. While there, I also set the Cluster DRS settings to manual, to prevent the VMs from moving during the upgrade. Once I obtained the information needed, I completed that portion of the json. (I’ve redacted environment specific information).
Lines 16 – 21 need data entries for the first vCenter appliance (vCenter-A) to be converged. Here I need the FQDN for vCenter-A, for the Username, I need the email@example.com account, its password, and the root password of the appliance.
Lines 22 – 33 would be filled out IF the Platform Services Controller (PSC) appliance is joined to the domain. My customer was joined to the domain, so I needed to fill this section out. Otherwise you can remove this section from the JSON.
Now, because this is the first vCenter of three, in the same SSO domain, for the first convergence, I did not need this section, because the first vCenter does not have a partner yet. It will be needed however, on the second (vCenter-B) and third (vCenter-C) convergences.
Now I need to fill out a second and third converge.json file for the second and third convergence, saving each in its respective folder. For vCenter-B and vCenter-C, for the partner hostname on line 32, I used the FQDN of the first converged vCenter (vCenter-A), as that is the first partner of the SSO domain.
For vCenter-A, the first to be converged, the completed converge.json looks like this (take note of the commas, brackets and lines removed):
For the second convergence (vCenter-B), and third convergence (vCenter-C), the completed converge.json looks like this:
Now that we got the converge.json done for each of the vCenters, we can work on the decommission.json.
Here is the template VMware provides in the same directory:
Lines 11 – 15 require impute for the Managing vCenter or ESXi Host of the External PSC. Again, just like the vCenter, I used the ESXi host that the PSC is running on.
Lines 16 – 21 needs data for the Platform Services Controller that will be Decommissioned.
Lines 30 – 34 requires information for the vCenter the PSC was paired with. Again here I just used the ESXi host that the vCenter is currently running on
Lines 35 – 39 require the information for the vCenter, the PSC is paired with.
Now that we have the decommission.json filled out for the first vCenter (vCenter-A), I have to repeat the process for the second and third vCenters (vCenter-B, vCenter-C). The full decommission.json should look like
Now that both the converge.json and decommission.json have been filled out for each of my environments (3), and stored in the same directory on the root of C, I can move forward with the Convergence process.
Prerequisites and Considerations Before Starting the Convergence Process
- The converge tool only supports the VCSA and PSC 6.7 Update 1. All nodes must be on 6.7 Update 1 before converting.
- If you are currently running a Windows vCenter Server or PSC, you must migrate to the appliance first.
- Before converting, take a backups of your VCSA(s) and PSCs in the vSphere SSO domain(VM snapshots, and DB backups).
- Know all other solutions using the PSC for authentication in the environment. They will need to be re-registered after the convergence completes and before decommissioning.
- A machine on a routable network which can communicate with the VCSA and PSC will be used to run the convergence and decommission process.
- Set the DRS Automation Level to manual, and the Migration Threshold to conservative. There will be be issues if the VCSA being converged is moved during the process.
- If VCHA is enabled, it must be disabled prior to running the convergence process.
- The converge process will handle PSC HA load balancers. Make sure you point to the VIP in the JSON template if you have them.
- All vSphere SSO data is migrated with the exception of local OS users.
- Best to take snapshots of the vCSA and external PSC VMs before continuing. We’ve already backed up the database, but it doesn’t hurt to have snapshots as well.
Executing the Converge Tool
Now that converge.json template for each vCenter (vCenter-A, vCenter-B, vCenter-C) is filled out properly, we can now execute. We will run the convergence tool against the first vCenter (vCenter-A). Note: We can only run the converge tool against one vCSA at a time.
In powershell, we can first run the following command before proceeding with the upgrade to see what options/parameters are available with the converge tool.
.\vcsa-converge-cli\win32\vcsa-util.exe converge --help
To execute the convergence tool against the first vCenter (vCenter-A), I ran the following command:
.\vcsa-converge-cli\win32\vcsa-util.exe converge --no-ssl-certificate-verification --backup-taken C:\pathtofile.json
The output in powershell should look something like:
It will then ask you to reboot the first vCenter before continuing.
Once the first vCenter (vCenter-A) came up, I executed the convergence tool for the second vCenter (vCenter-B). Once completed I restarted the appliance.
Finally, the last vCenter (vCenter-C) is on deck. I executed the converge.json against that vCenter, and once completed, I restarted it.
Here is where you would need to re-point those systems using the old SSO domain, but since I didn’t have any, I can move forward with the decommissioning steps.
Decommissioning the Old external Platform Services Controllers (PSC)
Using the Converge Tool with the decommission option to remove the external PSC’s. Just like before, we need to do this one PSC at a time. The command looks something like this:
.\vcsa-converge-cli\win32\vcsa-util.exe decommission --no-ssl-certificate-verification C:\pathtofile.json
Once the process successfully completes, move onto the next PSC. Repeat the process until all PSC’s have been decommissioned.
Validate the SSO Replication Topology After the Converge Process
If you’ll remember, when I setup the converge.json, I had the second vCenter (vCenter-B) and third vCenter (vCenter-C) replication partner set to the first converged vCenter (vCenter-A). My Replication topology currently looks like this:
I needed to close the loop between vCenter-B and vCenter-C. Using VMware’s KB2127057 , I used the ‘createagreement’ parameter. I opened a putty session to vCenter-B and ran the following command:
# cd /usr/lib/vmware-vmdir/bin
./vdcrepadmin -f createagreement -2 -h vcenter-b.domain.com -H vcenter-c.domain.com -u Administrator -w VMw@re123
Now that the SSO replication agreement has been made between vCenter-B and vCenter-C, my replication topology looks like this:
I’m not going to lie, the hardest part of using the convergence tool, was just getting started. I’ve been through enough fires in my day to know how bad of a time I would have had if something went wrong, and I lost either the vCenter, or external PSC before the convergence successfully completed. Once I got myself beyond that mental hurdle, the process was actually quite easy and smooth.
I know I’ve left this customer’s environment in a lot better shape than I found it, and having embedded PSCs will make future vCenter upgrades a breeze. For a VMware PSO consultant, this was a huge value add for the customer.
Blog Date: April 16, 2019
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