Vsan Stretched Cluster

https://docs.vmware.com/en/VMware-vSphere/7.0/com...
Introduction to Stretched Clusters Stretched clusters extend the vSAN cluster from a single data site to two sites for a faster level of availability and intersite load balancing Stretched clusters are typically deployed in environments where the distance between data centers is limited such as metropolitan or campus environments

https://docs.vmware.com/en/VMware-vSphere/8.0/vsan...
A vSAN stretched cluster must meet certain basic networking requirements Management network requires connectivity across all three sites using a Layer 2 stretched network or a Layer 3 network The vSAN network requires connectivity across all three sites It must have independent routing and connectivity between the data sites and the witness host

https://www.vmware.com/content/dam/digital...
The final step before we can configure the Virtual SAN Stretched Cluster is to ensure that the hosts residing in the data sites can reach the witness host s VSAN network and vice versa In the screen shots below there are SSH sessions opened to a host in data site 1 a host in data site 2 and the witness host

https://blogs.vmware.com/.../2019/01/14/vsan-stretched-cluster
The deployment of vSAN Stretched Cluster is completed using the vSphere wizard connecting a minimum of 2 maximum 30 hosts across two active active sites using an ESXi host physical or virtual appliance as a witness residing at a third site The data sites are connected via a high bandwidth low latency network link

https://www.vmwarearena.com/create-vsan-stretched-cluster
To enable the vSAN in the cluster Select the Cluster configure General Click Configure Select the option Configure Stretched cluster and click on Next Network validation wizard will check whether all the hosts are configured with the vSAN VMkernel interfaces You can see a green checkmark Yes under vSAN Enabled

https://core.vmware.com/resource/vsan-proof...
Stretched Cluster Setup To start the configuration wizard for either vSAN stretched cluster or two node navigate to Cluster Configure vSAN Services and pick the appropriate option Follow the screens to configure the disks as per a standard vSAN cluster Then chose the vSAN witness host

https://masteringvmware.com/how-to-configure-vsan-stretched...
Step 1 Login to vSphere web client Select your vSAN Cluster Go to Configure Tab Select Fault Domains under vSAN Section Here you will see Stretched Cluster is currently disabled Click Configure to configure stretched cluster Step 2 You will have to configure Preferred secondary fault domain here

http://vmware360.com/.../vsan/...Stretched-Cluster-Guid…
Hosts per cluster The minimum number of hosts in a Virtual SAN Stretched Cluster is 3 In such a configuration site 1 will contain a single ESXi host site 2 will contain a single ESXi host and then there is a witness host at the third site the witness site The nomenclature for such a configuration is 1 1 1

https://www.vmware.com/content/dam/digital...
Deployment The stretched cluster allows the Virtual SAN customer to configure two geographically located sites while synchronously replicating data between the two sites This provides high availability and protection against a single site failure This white paper examines the performance aspects of a Virtual SAN stretched cluster deployment