official definition about "Federation" in SimpliVity

[J-Philippe]

Hello to the SVT Community, I'm looking for deep dive explanation or an official definition about "Federation" in SimpliVity. In somes guides 2 Hosts make a federation, in some other docs we speak about federation for host across datacenter (which one ? location or datacenter UO / Folder in a vCenter) https://www.hpe.com/psnow/doc/a00019351enw  "For example, a modest federation of a few systems contains tens of billions of deduplicated, compressed, and optimized 8 KB elements. The platform enables this federation to track and manage all elements efficiently and makes real-time decisions about which data elements to send via replication and which need not be sent due to the existence of an exact match at the destination site." https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-a00027987en_us&docLocale=en_US "An HPE SimpliVity federation uses at least two HPE OmniStack hosts. HPE OmniStack hosts include HPE OmniStack technology that uses deduplication and compression to efficiently store, manage, and share data. Each HPE OmniStack host also has a dedicated virtual machine called the Virtual Controller. The Virtual Controller runs the HPE OmniStack software." When deploying SVT node we set an SVT_FedPortGroup without routing (regarding preflight kit): "MTU 9000 10 Gbit/s . Communicate with OVC within same Datacenter No gateway/routing between sites Federations subnet of differents sites must be differents Dedicated VLAN is highly recommanded for federation networks on each site" But how can SVT use the Federation between Datacenters (if we talk about geographical location) if there's no routing ? How the OVC can talk each other to decide what KB must be sent or not to the other site ? Or are they speak through the Management Network between site and then pass the information "localy" to other OVC within the cluster through the federation port group ? A clear statement will be welcome about that topic Thanks for your help. Apologize for my english Jean-Philippe

[Moderator edit: Updated the broken link. You may also refer to https://support.hpe.com/]

[kmsj13]

I believe they speak on the management network, I was also wondering on that "Federation" Network, 

[JohnHHaines · Accepted solution]

It's a simple idea that actually defies a concise explanation.

The SimpliVity Federation is all the SimpliVity systems managed by a common vCenter infrastructure (which could be one or many vCenters), sharing a common authentication domain/source.

So, it could be as small as a single node with a single vCenter. Or it could comprise many clusters across multiple vCenters - but they must be in Linked Mode. If you deploy two nodes into two different vCenters which are NOT in Linked mode, you create two separate Federations.

We prefer to see the product deployed in HA mode, which requires at least two nodes for a cluster, but that is not a technical requirement – you can deploy a single node, that will still create the Federation.

The Federation database is replicated across all nodes in the Federation.

It’s easy to confuse the SimpliVity Federation with the Federation Network ( SVT_FedPortGroup), but they are not at all the same thing.

The Federation Network is used within a cluster for Federation-related traffic between nodes in the cluster. It is logically separated from the cluster Storage traffic, even though they run over the same physical network.

Replication of information between clusters is usually (and assumed to be) over the OVC Management Network (however, if separate clusters can communicate over the Federation Network, they will - but it is not required). This includes both Federation-related information (installation of a new node, for example), and Data (replicating a backup).

The SimpliVity OVC is responsible for replicating Federation Information both within a cluster and between clusters.

[kmsj13]

If you deploy two nodes into two different vCenters which are NOT in Linked mode, you create two separate Federations.

I would like to clarify on this matter, i understand that in order to create a federation between mulitple vcenters, they must be in linked mode, but is it possible to deploy it in separate vcenter first before joining them on a linked mode? 

[JohnHHaines]

No. There is no way to "merge" Federations, short or re-deploying the node(s). When you deploy the first node into a vCenter with no exisitng Federation, a new Federation is created, and there is no way to put them together. I think that falls into the category of something we'd like to do, at some point in the future.

But consider - if you want the SVT nodes in the same Federation, that's because you want to leverage single pooint of management, and SimpliVity replication. To do that, you need a network that would support Linked mode vCenters, anyway.

[J-Philippe]

@JohnHHaines => Thanks so much, the explanation is quite simple know I've read your post. Once again : Merci monsieur Regards, Jean-Philippe

[JLKT]

Hello John, is there a possibility to "split" federation? I need to migrate some VMs with their backups to another Simplivity solution, which after migration will be separated. I was thinkin to do at LinkedMode vCenter and after migration to repoint vCenter to another SSO domain. (https://docs.vmware.com/en/VMware-vSphere/6.7/com.vmware.vcenter.install.doc/GUID-9CB77874-D032-4C94-99AA-5340CB922F57.html#GUID-9CB77874-D032-4C94-99AA-5340CB922F57)

[JohnHHaines]

Not that I am aware of, no. No "split" and no "merge".

All the nodes have the same Federation DB, and expect to be able to  contact all the other nodes. In theory you could physically split them, and start trying to repair the Federation by removing nodes, but I suspect it would not work. It would certainly be a science project <g>. Even if it appeared to be working, I suspect there would be underlying issues that would eventually surface to bite you

You coudl stand up the new environment as a separate Federation (different vCenter) and migrate the VMs using the cross-vCenter Fling (https://flings.vmware.com/cross-vcenter-workload-migration-utility), but not the backups - there is no way to copy backups between Federations.

[rdz1]

Good Morning,

I was reading your explanations and i 've a question regarding Federation.

For management and security purposes, is it possible to have different Federation for two SImpliVity Cluster in the same vCenter?

Thx

Regards