Transitioning to the vSAN 8 Express Storage Architecture
vSAN Express storage architecture (ESA) is a new optional architecture available with the latest VMware vSAN 8 release. This new architecture offers greater performance for NVMe-based TLC flash devices for both on-premises environments, and for the public cloud hyperscalers. With vSAN 8 customers will be able to choose which one of the two existing architectures (vSAN Original Storage Architecture or vSAN Express Storage Architecture) best suits their needs. Customers can easily upgrade existing vSAN clusters to vSAN 8 using the Original Storage Architecture (OSA) by using vLCM. Customers who want to transition to vSAN 8 using the Express Storage Architecture, can do so by creating a new cluster and enabling the new vSAN Express Storage architecture.
Fig.1. Enabling vSAN ESA for a vSAN cluster
For now vLCM will be using only the Original Storage Architecture. If customers want to take advantage of the new vSAN ESA, they’ll need to take a look at the following detailed steps before they make the transition.
Let’s check what are the requirements to transition to the new vSAN Express Storage Architecture. First, the Express Storage Architecture requires the use of vSAN ReadyNodes that are approved for use with the ESA. Note that with the initial release of the ESA in vSAN 8, build-your-own configuration is not a supported option. Second, once the appropriate license is available, which in this case should be a vSAN Advance or a vSAN Enterprise license, customers can migrate their VMs from vSAN OSA to the newly created vSAN ESA cluster. The migration process can be accomplished using vMotion and SvMotion.
Although different versions can seamlessly co-exist in the same vCenter Server, VMware recommends upgrading existing vSAN clusters to vSAN 8 OSA to take advantage of the newest enhancements.
We would like to emphasize that using the correct qualified hardware is essential to the installation process of vSAN 8 using the Express Storage Architecture. Therefore, new pre-checks will be implemented in vSAN 8 ESA to prevent enabling the architecture on non-qualified hardware and to ease the deployment process. Customers should also make sure that they check the specific network requirements for the ReadyNode hardware they have chosen.
Fig. 2 vSAN ESA incompatible disk notification
vCenter Server should be running the latest edition of the software to make sure it will be fully compatible with the clusters that might be from different older versions and different architectures. Since a vCenter Server running vCenter Server 8 can manage a vSAN cluster with older editions of vSAN, and using both architectures, migrating workloads is nothing more than a simple shared-nothing vMotion.
Transitioning to vSAN ESA helps customers maximize the value of their existing modern hardware by enabling greater levels of performance and efficiency for their workloads. Businesses that are still considering their options to transition to ESA can take advantage of all the latest functional benefits by upgrading to vSAN 8 OSA.
For more details on transitioning to the ESA, see "Migrating to the Express Storage Architecture in vSAN 8."