How to add secondary PSC and configure replication for those

[alex_vsphere]

Hello. I have the following setup in my lab.

DC 1 / Cluster one: PSC01 + vC01

DC 2 / Cluster two: PSC02 + vC02

What I want to next is:

- Add PSC03 in DC 1 / Cluster one

- Make PSC01 and PSC03 replicate with each other

Then:

- Make PSC03  from DC 1 / Cluster one replicate with PSC02 in DC 2 / Cluster two

- Make PSC02 from DC 2 /Cluster two replicate with PSC01 from DC 1 / Cluster one

Could this be implemented via GUI or must it be via command line?

Which commands should I be familiar with?

Best regards!

[rajen450m]

HI Alex,

Adding secondary PSC is nothing but configuring PSC HA. So, please find the below articles about the configuration of the same:

Configuring Platform Service Controller HA in vSphere 6.5 (2147018)

VMware Knowledge Base

Configuring Windows PSC for High Availability in vSphere 6.5/6.7 (2147527)

VMware Knowledge Base

[alex_vsphere]

Hello. My purpose is to obtain this

http://https://www.youtube.com/watch?v=68OlDARa2ag

See minute 22.

I do not think that it requires Load balancer.

I am going to try and deploy PSC03 as replication partner. And see how it goes. Thank you!

[alex_vsphere]

During the installation, I have to choose THE SAME SITE. I think that this is how to be done.

[daphnissov]

Yes, this is a PSC replication in ring topology and not the same as HA. It does not require a load balancer. You can either choose to replicate within the same site or declare a different site to be a replica partner.

[psibaja · Accepted solution]

Hello alex_vsphere,

I have a question for what you are trying to accomplish, I believe that when you say "DC1" and "DC2" you are talking about different vSphere SSO Domains, am I right? or are you talking about OpenLDAP or MS Active Directory domains?

The reason I am asking that is because when you install your first PSC (PSC01) you have to create a new SSO Domain (normally called vsphere.local), then when you want to deploy another PSC (PSC02) you can either create new SSO domain or join an existing SSO domain. In order for these PSCs to replicate information you have to have them in the same SSO domain, so you had to join PSC02 to the existing SSO domain of PSC01 at the very beginning. There is no way to change the SSO domain of a vCenter or PSC once they have been joined to one when deployed. You can read this for more info: Understanding vSphere Domains, Domain Names, and Sites

So, if you want deploy a 3rd PSC (PSC03) and join it to the SSO domain of PSC01, you can do that for sure, and you can also specify a different site for this new PSC03 (a site is just a logical separation in the domain for the PSC that is normally used to identify geographic locations). Once you deploy PSC03, follow this documentation article to make sure the replication agreements are created and running between PSC01 and PSC03: Configure Replication Agreement Between All External Platform Services Controller Instances

The problem starts when you want to create a replication agreement between PSC03-PSC02 and PSC02-PSC01, if PSC02 is joined to a different SSO domain, here relies my question this is because replication agreements only work between PSCs of the same SSO Domain (can be separate sites inside the same SSO Domain too).

There is also no way to do this from the Flash Web Client or the HTML5 Client, only though the CLI.

If you have more questions let me know.

Regards.

[alex_vsphere]

Hello.

Thank you for a good answer. I use the same SSO domain and two sites.

The only think I do not see in that documentation is how to remove a replication relation between two psc. I suppose that removing a replication relation is not the same thing as decommissioning a psc. Right?

My psc01 replicates with psc02 and psc03 now. I want psc01 to replicate only with psc03. psc03 only with psc02 and psc02 only with psc01.

is there a command for removing a replication relation?

Best regards!

[psibaja]

Hello there,

For that I have another KB that you can use, it has a few commands that you can have in handy to show the status of the replication agreements, to create and also remove an agreement, check this out: Determining replication agreements and status with the Platform Services Controller 6.x

In that KB there is a section called "Using the removeagreement parameter" and with the process you can remove the replication agreements that you do not want but, my recommendation is to first create the agreements and then remove the extra agreements you want to delete.

And to finish, a removing a replication agreement is not the same as decommissioning a PSC. These are different processes, so removing a replication agreement now does not impact your ability to create it again later if you wish.

Cheers!

[alex_vsphere]

Psibaja,

Thank you for a very good answer. I will have a look  at the KB.

Best regards!

[alex_vsphere]

Psibaja, thank you for your good answers.

Verry helpfull.

Best regards!

[psibaja]

You are welcome alex_vsphere! I am glad that my answers helped you out.

Take care!

Pablo