Comparing vSAN Architectures OSA x ESA is an article comparing both vSAN architectures OSA and ESA.
First and Foremost, What is vSAN ESA?
OSA is an acronym for Original Storage Architecture. It is the original vSAN architecture released when vSAN was made. ESA is an acronym for Express Storage Architecture. It is a new vSAN architecture released in November 2022 and introduces many improvements compared with the OSA architecture. However, the ESA will not replace the OSA. Both architectures are available (you can choose what architecture to use):
vSAN Express Storage Architecture, or ESA for short, is a new vSAN architecture to process and store data. It is an optional alternative designed to achieve new levels related to efficiency, scalability, and performance.
vSAN ESA is optimized to exploit the full potential of the latest hardware and unlock new capabilities. At this moment, vSAN ESA is only supported on ReadyNodes servers. To learn more about vSAN ReadyNodes, please, check the following link:
https://www.vmware.com/resources/compatibility/vsanesa_profile.php
Consolidated Comparison Between vSAN Architectures
So, I have created a figure to show a comparison between vSAN OSA and vSAN ESA in a practical way. I want to be clear that we can talk about in a deep way each item described in the following figure, however, the aim here is just to provide a consolidated view for both vSAN architectures:
The vSAN OSA uses disk groups and vSAN ESA uses a storage pool configuration to manage its devices. In the following figure, we have a vSAN OSA cluster on the left and a vSAN ESA on the right:
With a vSAN Original Storage Architecture (OSA) cluster, the disk group is an integrated part of this architecture. Independent of the cluster type (Hybrid or All-Flash), the disk group is part of its architecture. All disk groups work together to create the vSAN datastore.
Instead of using a disk group, a storage pool is used with a vSAN Express Storage Architecture (ESA) cluster. It is a logical group of disks, working together to create a pool. All hosts in a vSAN ESA cluster can contribute with their storage pool to create the vSAN datastore.
To Wrapping This Up
Both vSAN architectures can be used (you can choose OSA or ESA). However, you need to check the hardware requirements for each architecture. A vSAN ESA cluster has specific hardware requirements, so, based on this, you need to check deep it before building your vSAN ESA cluster.