Now that vSphere 6.0 is here and we can use FT to protect all of our precious management VMs like the vCenter, is the concept/use of a "Management Cluster" still relevant?

[AndreReds]

Hi All,

We are moving into vSphere 6.0, currently we are in 5.5U3, and our environment was deployed having a Management cluster (only for vCenter and a few management VMs , the cluster has 2 hosts each with 128GbRAM, 2x10 Gb CNA cards and 24 CPUs) and several other clusters for our Prod and Dev VMs.

So now we are looking to optimize our hosts and use features like vMotion, HA, DRS and the improved FT.

As per VMware support, you can use FT on the vCenter Appliance as long as it is deployed as Tiny or Small (and this is our case), also VMware support told me that once you enable FT on a VM, that VM creates Reservations for all its resources, so that they are guaranteed for but the Running VM and the FT-copy.

So if we have these reservations in place and we are 100% sure that our vCenter (and other VMs that have FT enabled) will have to compete with other VMs or be starved for resources, do we still need the "Management Cluster"? To me looks like it would be a huge waste of resources to keep it, instead I want to boost up the hosts to 382GB RAM and add them to our prod cluster (once we migrate to vSphere 6.0)

What do you guys think? Any ideas? Suggestions? Pros/Cons?

Thx,

Andre

[rcporto]

Note that the motivations for the existance of the management Cluster is not provide enhanced high availability and reserved resources to your vCenter and your infrastructure services (VMs), but for example, is about provide a isolated cluster where you can do some tasks without the risk of impatc in your productions virtual machines, and even with FT on vSphere 6, the management cluster is still a best practice.

Take a look at this excelent blog post for some pros/cons about the management cluster: Why to create the VMware Management Cluster? | Settlersoman - A settler in the SDDC world.