Part 7 of the 10-part VCF series. This technical reference guide details the storage architectural decisions, core capabilities, and deployment boundaries required when designing storage pools for VMware Cloud Foundation (VCF) 9.x.
Core Integration Requirements
In VCF 9.x, vSAN is the primary software-defined storage layer, automating the creation of shared datastores, with the Management Domain strictly requiring a native vSAN configuration. While external storage (FC, iSCSI, NFS) is supported for workload domains, vSAN is central to the architecture.
Technical Evaluation: vSAN OSA vs. ESA
VCF 9.x offers two storage models, with the choice impacting server hardware (BOM) and lifecycle management.
- Original Storage Architecture (OSA): Uses disk groups with dedicated cache and capacity drives (up to 5 groups per host), supporting legacy SAS/SATA SSDs and HDDs. While flexible, it offers lower performance compared to ESA due to architectural limitations.
- Express Storage Architecture (ESA): The recommended standard for new VCF 9.x deployments, eliminating disk groups for a unified, high-performance pool. ESA requires certified NVMe hardware, delivers superior performance, and unlocks advanced features like adaptive RAID 5/6, global deduplication, and efficient snapshots.
Platform Lifecycle Boundaries and Deprecations
- vVols Support: Broadcom deprecated vSphere Virtual Volumes (vVols) in VCF 9.0, with support limited to security patches in 9.1. Migration to vSAN or VMFS is recommended.
- Stretched Clusters: Fully supported for both architectures, but mixed OSA/ESA configurations within a stretched deployment are not permitted.
Storage Policy Based Management (SPBM)
vSAN uses SPBM for data protection (FTT/RAID). ESA provides improved efficiency using adaptive RAID 5/6, which optimizes capacity usage compared to traditional OSA mirroring.
Capacity Entitlements and Sizing
- VCF Licensing: Includes 1 TiB of vSAN capacity per licensed CPU core.
- VVF Licensing: Includes 0.25 TiB of vSAN capacity per core.
Admins must calculate required capacity and FTT overhead, using add-on licenses or vSAN Max for disaggregated storage needs.
Architectural Recommendations
ESA on NVMe is the recommended path for new VCF 9.x environments, with OSA supported for legacy, and vVols migrations necessary before future updates.
Next in Part 8, we step into the day-to-day operations of building, scaling, and managing Workload Domains.