vSAN Stretched Cluster: A Solution for Disaster Avoidance
In today’s digital age, data is the backbone of any business. Losing access to critical data can be disastrous, especially for organizations that rely on it to operate their daily activities. Therefore, it is essential to have a robust solution that ensures high availability and avoids potential disasters. One such solution is vSAN Stretched Cluster, introduced in vSAN 6.1, which provides an active-active fashion for high availability.
In this blog post, we will delve into the concept of vSAN Stretched Cluster, its use cases, requirements, and network considerations. We will also discuss the benefits of using vSAN Stretched Cluster in disaster avoidance scenarios.
What is vSAN Stretched Cluster?
vSAN Stretched Cluster is a new architecture introduced in vSAN 6.1 that allows ESXi hosts to be placed in two different physical locations and join together with high bandwidth low latency networking. Despite being in two different sites, the hosts belong to one single vSAN cluster and share their resources. This solution provides an active-active fashion for high availability, ensuring that applications remain accessible even in the event of a disaster.
Use Cases
vSAN Stretched Cluster is ideal for use cases where disaster avoidance is critical. Some examples include:
1. Data centers located in different geographic locations.
2. Organizations with remote offices or branches.
3. Disaster recovery and business continuity planning.
Requirements
To deploy a vSAN Stretched Cluster, there are several requirements to consider:
1. ESXi hosts must be evenly spread between two sites.
2. A witness node is required to hold the witness components. The witness node can be installed as a dedicated physical ESXi host or a specialized virtual witness appliance.
3. Networking requirements include high bandwidth low latency networking between sites.
4. MTU should be set to 9000 for performance purposes, but it must be feasible in your infrastructure.
Network Considerations
When deploying a vSAN Stretched Cluster, network considerations are critical. Here are some key points to keep in mind:
1. End-to-end MTU: Set the MTU to 9000 if it’s feasible in your infrastructure.
2. Inter-site networking: Ensure that high bandwidth low latency networking is established between sites.
3. Network congestion: Avoid network congestion by sizing the inter-site links appropriately.
Benefits of vSAN Stretched Cluster
The benefits of using vSAN Stretched Cluster in disaster avoidance scenarios are numerous, including:
1. High availability: Provides an active-active fashion for high availability, ensuring that applications remain accessible even in the event of a disaster.
2. Disaster recovery: Allows for disaster recovery by replicating data between sites.
3. Business continuity: Ensures business continuity by providing access to critical data and applications even in the event of a disaster.
4. Reduced downtime: Minimizes downtime by allowing applications to remain accessible during maintenance or upgrades.
5. Improved scalability: Scales seamlessly as data grows, eliminating performance bottlenecks.
Conclusion
In conclusion, vSAN Stretched Cluster is a powerful solution for disaster avoidance scenarios. Its active-active architecture ensures high availability, while its ability to span multiple sites provides a robust disaster recovery solution. By understanding the requirements and network considerations, you can deploy a successful vSAN Stretched Cluster in your environment. Don’t wait until it’s too late, adopt vSAN Stretched Cluster today and ensure the continuity of your business.
About the Authors
Sadaf Allahyari & Shahrouz Lahiji are Data Center & Cloud specialists. Both are double VCIX on Data Center & Network virtualization, vExperts and also VMUG leaders in Sweden.