We are about to jump from 5.5 to 6.5.2. We have 3 sites on island that have very solid connections
to each other. Each site has it's own clusters and vcenters which makes management a pain.
As we see it we have two options to clean things up-
1. Put all the necessary pieces and parts on the same management network and have one vcenter.
2. Used Enhanced Linked Mode at each site.
Any advice is very much appreciated..
There are advantages to both options, as well as disadvantages.
Latency is certainly a concern which may lead you down the Enhanced Linked Mode route.
How "solid" are the connections to each site?
When you say "the same management network", are you referring to a single location? or your ability to stretch a layer 2 network across all sites?
Are there multiple connections from/to each site? (I.E. Site 1 connected to Site 2 directly and Site 3 directly, Site 2 to Site 3, etc.)
What other services/software are you using in your configuration? Site Recovery Manager? Native/array Based Replication?
Most of the time, the need to have the ability to manage an environment out weighs simple configuration. Typically I would suggest an ELM configuration with PSC/vCenter at each site so that if the primary site (wherever solo vCenter would live) went offline, the other sites would not be affected in any way and would still be manageable without any intervention. It also eases management since you have access to all vCenters from one window.
You could combat the solo disadvantage with vCenter HA though, potentially hosting your secondary vcsa in one of the other sites assuming latency requirements are met.
Hope you find your answers,
The connections between the sites are fast and solid as a rock - < 1ms latency. I can go to any of the 3 sites
and see no lag whatsoever. Site 1 and 2 are maybe 2 miles apart. Site 3 is 27 miles from both site 1 and 2.
Other than site 3 hosting its own stuff, site 3 is evolving as a DR site for sites 1 and 2 using Zerto. And that
can be done because any VLAN (including the proposed management x.x.2.x VLAN) can be made available at any site.
Sites 1 and 3 already already have this. Site 2 we adopted, so some minor network configging would need be done
to include it.
Site 1 and site 2 are directly connected due to their proximity. Site 3 is a spoke off our island-wide ring.
Use linked mode, the main reason was mentioned before, if you lost the datacenter with vcenter in it you will be without. The only way I wouldn't use the second vcenter is you couldn't justify the cost if you needed to buy a new vcenter license. Having the vcenters separate also opens the ability to use DR tools like Site Recovery Manager to recover your critical VMs in one of the sites.