VMware vSAN 2-Node Cluster is a configuration implemented in environments where a minimal configuration is a key requirement, typically in Remote Office and Branch Office (ROBO). A VMware vSAN 2-Node Cluster on VxRail consists of a cluster with two directly connected VxRail E560 or E560F nodes, and a Witness Host deployed as a Virtual Appliance. The VxRail cluster is deployed and managed by VxRail Manager and VMware vCenter Server.
A vSAN 2-Node configuration is very similar to a Stretched Cluster configuration. The Witness Host is the component that provides quorum for the two data nodes in the event of a failure. This vSAN 2-Node configuration includes two deployment architecture, i.e. the vCenter server and Witness host can locate in a main datacenter or same location. The following are the two options of deploying vCenter and Witness.
Remark: RTT between Witness and data nodes up to 500ms. Bandwidth of at least 1.5Mbps. Minimum VxRail software version is 4.7.100
2-Node Licensing Options for vSAN
Option A: vSAN ROBO license
- Per-VM licensing model (Standard, Enterprise, Advanced editions)
- Support total of 25 powered-on VMs in single location or across multiple locations
Option B: regular vSAN license
- Deployments running more than 25 VMs
- Per-socket licensing model
vSAN 2-node basics
- Both nodes must be in a single physical location
- Only supports PFTT=1, mirroring (VM objects are mirrored across two nodes, FTT=1)
- Witness host required as the tiebreaker
- 3 fault domains (Witness host included)
- Can use either normal per-socket vSAN licenses or the per-VM vSAN ROBO licenses
Witness host
- Virtual appliance running ESXi (multiple sizes depending on VM count)
- Receives Witness traffic from the two nodes
- must run outside of cluster and requires Witness traffic separation
- Can run on a host within the same rack, but not in the 2-node cluster
vCenter and Witness host on separate server or cluster at a same site
- Ports 1 and 2 for HA for ESXi management, VM network, and Witness traffic
- Ports 3 and 4 for vSAN and vMotion directly connected to each other
- Separate Witness management traffic from vSAN traffic
- vCenter server cannot be installed in the same cluster
vCenter and Witness are locate in HQ datacenter.
Victor Wu
Chief Architect, Blogger, Author at Dell EMC Knowledge Sharing & Packt
Victor Virtualization 
hi
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What can I help you ?
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What would be the impact of failure of one node? Would the VM services be affected in any way?
Will the VMs be in read-only mode?
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Only supports PFTT=1, mirroring (VM objects are mirrored across two nodes, FTT=1). The VM is still running in health if the impact of failure of one node. Best practice to run less than 50% of a nodes resource load, so a single node can bear full cluster load in case of a node failure.
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I am a debutant on the Dell Vxrail, friends help me to put in place, I have three Vxrail that we must put them in a cluster and I have two TOR switch
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What is your problem ? Please let me the details.
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hello i have problem.
i’m deploying vxrail 2node cluster.
but i got 2 error message.
1. vsan cluster configuration consistency. – network configuration is out of sync2
2. witness host not found.
192.168.1.155
ㄴ192.168.1.191<-witness
192.168.1.110
ㄴ 192.168.1.51<- venter
ㄴ192.168.1.202vsan health alarm “witness host not found”
>vsan cluster configuration consistency
i checked all network configuration and ping.
(like vmkping, esxcli network ip neighbor list -i vmk1)
and vxrail 2node deploy was stopped at step 55.(Configuring storage policies on vcenter server)
at the same time in vcenter’s recent task show me
“invalid virtual machine configuration
there are currently 2 usable fault domain the operation requires 1 more usable fault domain”
I don’t know what problem caused this.
I’ve been looking for the cause for two months from step 55.
can you help me?
if you need remote connection. i will support remote connection like team viewer.
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May I know the details of IP settings for vCenter/ESXi network and vSAN network?
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Hi!
I would like to try the vmware VxRail software where do I download it?
How much is an annual license or lifetime license?
I would like to try the software in trial but complete with features to create rack servers or create cluster servers with GPU.
I would like more information.
I would like a price list for each virtual rack which is the most convenient.
But I would like to try this software vmware VxRail.
Thank you and waiting for answers.
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This is a black box solution, all licenses and software are bundled on VxRail appliance.
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Hi, i realy need help in deploying 2-Node Cluster. In the validation Prozess i get the message, that Resource not found secondaryPg. It cant be a switch issue. Have yue a idea?
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What is your architecture of 2-Node cluster?
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Hi did you find the solution for “Resource not found secondaryPg.”
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I do not have enough information for troubleshooting.
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I have found solution for SecondaryPg Not found. This issue occur when the vSAN appliance is not added to vCenter Server. I have struggled for two weeks and then I have gone through the Dell Deployment guide and it is clearly mentioned that to add the vSAN Applicance to vCenter after deployment of Appliance.
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Great to hear that the issue was solved.
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Hi,
Getting below error on Vxrail 2 Node setup with 1 witness server in DC
Unable to verify the network connection between the witness node and the data node. The witness traffic connectivity among hosts appears down.
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Did you verify the network requirements for deployment of vSAN 2-Node cluster? All requirements are fulfilled?
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Yes
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I don’t know your network architecture of vSAN 2-Node cluster, no idea in this moment. Please share it to me with email if you can.
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Hi
Any idea on below error also pls share me the witness server deployment and steps in remote DC..
Getting below error on Vxrail 2 Node setup with 1 witness server in DC
Unable to verify the network connection between the witness node and the data node. The witness traffic connectivity among hosts appears down.
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I try to look for some useful information for reference. Please stay tuned.
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