Recently I have had some very interesting conversations on the use of “2 Node” and “ROBO” with vSAN.
Where does it fit in the enterprise? When should a business use this approach etc?
It appears that the use of the terms “ROBO” and “2 Node” have also become interchangeable with respect to vSAN.
With the flexibility and features within the vSAN editions, it could be easy to misunderstand the concepts and use cases for this architectural approach and not consider the opportunity that is there for a ROBO deployment.
Based on a variety of workshops and discussions I thought I would highlight;
Some common architectural thoughts for vSAN ROBO.
- vSAN ROBO is designed for platforms outside of a companies HQ or datacenter.
- It is not a 2 node only SMB solution, it is a scalable architecture with can start with 2 nodes running workloads & grow to maximums such as 64 nodes.
- Using a repeatable design approach in & outside the corporate DC can help simplify storage needs, cost, time & operational management.
- From an architecture perspective, 2 nodes can be used with any vSAN version, while ROBO is a licensing approach with flexible deployment configurations based upon the number of VMs rather than sockets.
- It is possible to expand a 2 node platform to a larger platform without an outage.
- A 25 VM limit is based on powered on VMs and can be flexibility split between the site / VM number combination (ie 25 VMs across 4 locations) providing some real cost savings but still maintaining enterprise level storage experience.
- There are different network requirements with ROBO topologies that can potentially make vSAN appropriate to provide availability, security, and automation for applications which have to run locally with localized constraints and limited IT.
To aid discussions I have created a summary mindmap on the subject and listed some useful links below for more information.
Useful Links ROBO Solution Information https://www.vmware.com/files/pdf/products/vsan/vmware-vsan-robo-solution-overview.pdf Overview of vSAN 2 Node https://cormachogan.com/2017/03/10/2-node-vsan-topologies-review/ Licensing Documentation https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/products/vsan/vmware-vsan-67-licensing-guide.pdf vSAN Witness Placement discussion http://www.yellow-bricks.com/2016/09/20/running-vsan-witness-2-node-cluster-2-node-cluster/ VVD - 2 Node ROBO Documentation https://docs.vmware.com/en/VMware-Validated-Design/4.0/com.vmware.vvd.sddc-robo-design.doc/GUID-36BE6218-F11F-412A-B76B-1E9B4AE3535A.html 2 Node Common Config Questions https://storagehub.vmware.com/t/vmware-vsan/vmware-r-vsan-tm-network-design/2-node-vsan-deployments-common-config-questions/ 2 Node Direct Connect & WTS https://storagehub.vmware.com/t/vmware-vsan/vsan-6-6-proof-of-concept-guide/2-node-direct-connect/ Stretched Cluster 2 Node DR Scenarios https://storagehub.vmware.com/t/vmware-vsan/vsan-6-7-proof-of-concept-guide/vsan-stretched-cluster-and-2-node-without-wts-failover-scenarios/ Scaling 2-node VSAN (ROBO) to a 3-node or more https://blogs.vmware.com/virtualblocks/2016/02/26/scaling-2-node-vsan-robo-to-a-3-node-or-more/ Demo Video - Converting from 2 node to 3 node cluster https://www.youtube.com/watch?v=C3-RDxBprfc Blog post : Scaling ROBO https://blogs.vmware.com/virtualblocks/2019/02/25/vsan-robo/ VMworld Video - Deploying vSAN to 300 Stores in 2 Weeks: An Automation Story https://videos.vmworld.com/global/2018/videoplayer/26347 Read locality information https://blogs.vmware.com/virtualblocks/2016/04/18/2node-read-locality/