Geographically separated sites - one or multiple vCenter server instance?

[HPA_Admin]

Hi All,

Having searched around the we for a while, cannot find an answer to our particular scenario - throwing the question out to this forum.

We have recently renewed and upgraded licenses from ENT to ENT Plus.  With the new licenses ready to go, looking at upgrading hosts to ESXi 6.5.  This naturally means upgrading the vCenter server instance(s).

We have 3 geographically separated sites with all hosts running ESXi 6.0U3.  All three sites are in a hub and spoke model, site A as the hub with redundant links out to sites B and C.  Currently there is a single external PSC (located at Site A) and a vCenter server at each site in linked mode.

Site A (Sydney 1)

2 Clusters

Cluster 1 has 2 hosts running 7 VM's

Cluster 2 has 8 hosts running 39 VM's

Site B (Sydney 2) - Redundant 100Mbps links to Site A

1 Cluster of 10 hosts running 39 VM's

Site C (Brisbane) - Redundant 50Mbps links to Site A

1 Cluster of 4 hosts running 36 VM's

In the future Site A will be collapsed into Site B.  Taking this on board, am looking into the feasibility of reducing the number of vCenter servers (ideally into a single instance).  Reading around - whilst it is possible to manage a remote site.  Ruling out connectivity, I believe number of hosts and VM's at the remote site is one of the factors to be considered, however cannot find any information as to what the ideal limit is to depict local or remote vCenter server instance.

Am thinking of face lifting the architecture to be a single integrated PSC and vCenter server located at Site B, managing all three sites.

Feedback on which direction (collapse or leave as is) to take would be appreciated.

[daphnissov]

Something you might consider is to deploy/upgrade a vCenter at site B and then deploy a new vCSA at site C and link them. The vCSA at site B manages hosts in both sites A and B while C manages only C. Pro here is you keep C hosts locally managed due to latency and nearly 1,000 km in distance; con is you need a second vCenter license/seat.

[HPA_Admin]

Thanks daphnissov,

Totally agree and that is the initial thought / plan of attack, reducing the license from three back to two.

Running with the long term result (Site A and B collapsed into a single geographic location), weighing up the pro's and con's of collapsing into either a one or two vCenter server instances.

Taking into account the number of hosts and VM's at site C and the distance / connectivity, is there a guide to assist with defining deployment of a local or remote vCenter server instance.

[kenbshinn]

Are you doing anything other than managing the ESXi host? vSphere replication, Cross Site vMotion? What is your connectivity between site?

Depending on what you are looking at, I might consider 1 vCenter server at Site A or B and Definitely one at C, and put them both in the same SSO so you can do Linked Mode to manage them both from a single interface. That will also open you up to being able to use vSphere replication.

[HPA_Admin]

Hi Ken,

Used for management of the hosts, the primary features being used are DRS and HA.

After digging around a little, the release of 6.5U2 introduces Enhanced Linked Mode with embedded PSC, this looks like the way to go.

As site A will be collapsed into site B, install two instances - one at site A and one at site C

[ChrisFD2]

Absolutely look at embedded PSC, external ones are a pain!