ESA

Introduction vSAN’s storage architecture choice gets made before a single VM is ever placed – it’s a hardware and cluster-topology decision baked in at workload domain creation. VCF 9.1 supports two architectures side by side, Express Storage Architecture (ESA) and the Original Storage Architecture (OSA), and they claim disks in fundamentally different ways. Picking the wrong one for your hardware, or your operational model, is expensive to unwind later. Architectural Overview OSA: Cache and Capacity, Organized in Disk Groups Under the Original Storage Architecture, every host contributing storage needs at least one cache device and at least one capacity device, organized into one or more disk groups. Cache devices are SAS/SATA SSD or PCIe flash, and for hybrid configurations the cache tier needs to be sized at roughly 10% of anticipated capacity storage. Capacity devices differ by configuration: hybrid clusters use SAS/NL-SAS magnetic disks, all-flash clusters use SAS/SATA SSD or PCIe flash. OSA also requires a storage controller – a SAS/SATA HBA or RAID controller running in passthrough or RAID-0 mode – and host memory is sized based on how many disk groups and devices each host carries, typically worked out with the vSAN Sizer tool. ...

Introduction vSAN Express Storage Architecture (ESA) is the recommended storage architecture for all new VMware Cloud Foundation 9 deployments. ESA represents a ground-up redesign of the vSAN storage stack, purpose-built to exploit the performance characteristics of modern NVMe flash media. In this post, we explore the vSAN ESA architecture, design decisions, VCF 9.1’s new Auto-RAID capability, and best practices for storage policy design. Architectural Overview The diagram below illustrates the vSAN ESA architecture in a VCF 9 environment, from the NVMe hardware layer through the vSAN data path and management plane: ...