VMware Cloud Community
PLemetayer
Contributor
Contributor

How to setup a stretch cluster on 2 asymetrics Datacenters ?

Hi,

In my company we are considering VSAN. But our datacenter architecture is particular and I would like to know how can I do the following

Context : our datacenters are like this :

- 1 main datacenter with 2 isolated rooms, LAN latency

- 1 secondary datacenter with 1 room, 5ms latency from the main datacenter

- 1 DR site used as witness site

We plan to deploy for instance 3 ESXi+VSAN in each room, so 9 servers.

We would like the following

- A policy for bronze VM, 0 copy

- A policy for silver VM , 1 copy on the main datacenter

- A policy for gold VM, 1 copy on the secondary datacenter

I'm considering to deploy a stretch cluster on the 3 rooms

So

- the prefered fault domain will be the main datacenter

- the secondary fault domain will be the secondary datacenter

Bronze VM should have PFTT = SFTT = 0

Silver VM should have PFTT = 0 and SFTT = 1

Gold VM should have PFTT = 1 and SFTT = 0
But is there a trick to ask VSAN to store the two copies of silver VM separated on each room of the primary datacenter ?Because SFTT = 1 allow to be sure the VM will survive to a one host failure. But if we loose one room of the main datacenter, the two copies of the silver VM could be in the same room and so unreachable.I think to setup 4 faults domains, but it appears that stretch cluster support only 3 : 2 mains and a witness site.Thank youBest regards

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depping
Leadership
Leadership

there's no way to define fault domains within fault domains unfortunately at this point. it is something though that more customers have asked for and it is on the radar of our product management team. If/When/What/Where I can not comment on.

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