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VCF 9 Deployment Guide

vSAN Storage Requirements

vSAN Requirements for VCF 9

vSAN Version & Architecture

ESA (Express Storage Architecture):

  • Single-tier architecture using high-performance NVMe flash devices
  • Preferred architecture for VCF 9 deployments
  • Compression at top of storage stack (compress-once, write-anywhere)
  • Global deduplication (vs per-disk-group in OSA)
  • RAID-5/6 erasure coding with RAID-1-level performance
  • Up to 240% performance improvement over OSA on same hardware
  • Generates 2-3x more components per object than OSA

OSA (Original Storage Architecture):

  • Two-tier architecture with cache and capacity tiers
  • Still fully supported in VCF 9 (not deprecated)
  • Required for hybrid configurations (magnetic + flash)
  • Better option for organizations with existing non-NVMe hardware

Hardware Requirements

vSAN ESA:

  • Minimum 128 GB RAM per host (varies with storage pool size)
  • NVMe-only devices (no SATA/SAS support)
  • vSAN ESA ReadyNode from HCL required
  • No dedicated cache tier needed (single storage pool)
  • Minimum 3 hosts for vSAN cluster
  • vSAN Advanced or Enterprise license required

vSAN OSA:

  • Flash caching tier: minimum 10% of capacity tier size
  • All-flash: requires flash for both cache and capacity
  • Hybrid: magnetic capacity + flash cache devices
  • Disk groups required (unlike ESA’s single pool)

Boot Device Requirements:

  • Hosts ≤512 GB RAM: USB, SD, or SATADOM (min 32 GB)
  • Hosts >512 GB RAM: SATADOM or disk (min 16 GB, SLC preferred)

Networking:

  • 10 Gbps NICs minimum required for all VCF deployments

vSAN Configuration for VCF 9

Management Domain Storage Options:

  • vSAN (ESA or OSA) - 3 hosts minimum
  • Fibre Channel VMFS - 2 hosts minimum (NEW in VCF 9)
  • NFSv3 - 2 hosts minimum (NEW in VCF 9)
  • vSAN is no longer required for Management Domain

Additional Storage via Import/Conversion:

  • iSCSI, NFS v4.1, NVMe-oF (FC or TCP) supported when converging existing vSphere environments

Workload Domain Options:

  • vSAN ESA/OSA
  • VMFS on FC
  • NFSv3
  • External storage arrays

Storage Policy Defaults:

  • ESA clusters use auto-policy management for optimal defaults
  • FTT calculation: 2 × FTT + 1 = minimum hosts needed
  • ESA with RAID 0/1 uses 3 disk stripes regardless of policy setting

Deprecated vSAN Features

vSAN Hybrid OSA:

  • Officially deprecated in VCF 9
  • Will be removed in a future release
  • Migrate to all-flash OSA or ESA recommended

vVols (Virtual Volumes):

  • Deprecated in VCF 9.0
  • Full removal planned for VCF 9.1

Related Deprecations:

  • Host Profiles → replaced by Configuration Profiles
  • vCLS (vSphere Clustering Service) → retreat mode recommended
  • Enhanced Linked Mode → VCF Operations grouping replaces it
  • vLCM Baselines → image-based configuration only

Best Practices

Sizing:

  • ESA typically requires fewer hosts for equivalent workloads due to efficiency
  • 4 hosts recommended for Management Domain (3 minimum)
  • Plan for FTT requirements when sizing clusters

ESA Migration:

  • No in-place OSA-to-ESA migration available
  • Create new ESA cluster and migrate workloads
  • Verify hardware on vSAN ESA HCL before planning

Stretched Clusters:

  • Both ESA and OSA supported
  • ESA compresses before replication (reduces inter-site bandwidth)
  • Equal hosts per availability zone required

Sources