VMware vSAN V6.6 Part V (vSAN evolution and summary)

April 11, 2017 – 10:09 pm

server storage I/O trends

VMware vSAN V6.6 Part V (vSAN evolution and summary)

In case you missed it, VMware announced vSAN v6.6 hyper-converged infrastructure (HCI) software defined data infrastructure solution. This is the fifth of a five-part series about VMware vSAN V6.6. View Part I here, Part II (just the speeds feeds please) is located here, part III (reducing cost and complexity) found here, part IV (scaling ROBO and data centers today) located here.

VMware vSAN 6.6
Image via VMware

For those who are not aware, vSAN is a VMware virtual Storage Area Network (e.g. vSAN) that is software-defined, part of being a software-defined data infrastructure (SDDI) and software-defined data center (SDDC). Besides being software-defined vSAN is HCI combining compute (server), I/O networking, storage (space and I/O) along with hypervisors, management, and other tools.

How has vSAN (formerly referred to as VSAN) Evolved

A quick recap of the VMware vSAN progression which first appeared as part of vSphere 5.5. (e.g. vSAN 5.5 can be thought of 1.0 in some ways) consists of several releases. Since vSAN is tightly integrated with VMware vSphere along with associated management tools, there is a correlation between enhancements to the underlying hypervisor, and added vSAN functionality. Keep in mind sometimes by seeing where something has been, helps to view where going.

Previous vSAN enhancements include:

  • 5.5 Hybrid (mixed HDD and flash)
  • 6.2 (2016) All flash (e.g. AFA) versions included data footprint reduction (DFR) technologies such as compression and dedupe along with performance Quality of Service (QoS) enhancements.
  • 6.5 Cross Cloud functionality including the announcement of container support, cloud-native apps, as well as upcoming vSphere, vSAN, NSX and other VMware software-defined data center (SDDC) and software-defined data infrastructure (SDDI) technology running natively on AWS (not on EC2) cloud infrastructure.
  • 6.6 Modern data infrastructure flexibility, scalability, resiliency, extensibility including performance, availability, capacity and economics (PACE).


  • Distributed RAID
  • Per-VM SPBM
  • Set and change FTT via policy
  • In-kernel hyper-convergence engine
  • RVC and Observer


  • All-flash architecture
  • Perf improvements (4xIOPS)
  • 64-node support
  • High-density storage blades
  • Fault domain awareness
  • Scalable snapshots and clones
  • Disk enclosure management


  • Windows Failover Clustering
  • Oracle RAC support
  • HW checksum and encryption
  • 2-node ROBO mode
  • UltraDIMM and NVMe support
  • Stretch clusters
  • 5 min RPO (vSphere Rep)
  • SMP-FT support
  • Health Check, vROps, Log Insight


  • IPv6 support
  • Software checksum
  • Nearline dedupe and compression on all-flash
  • Erasure coding on all-flash
  • QoS IOPS limits
  • Performance monitoring service


  • iSCSI
  • 2-Node direct connect
  • PowerCLI
  • Public APIs and SDK
  • 512e support
  • All-Flash to all editions

Where to Learn More

The following are additional resources to find out more about vSAN and related technologies.

What this all means, wrap up and summary

VMware continues to extend the software-defined data center (SDDC) and Software-Defined Data Infrastructure (SDDI) ecosystem with vSAN to address the needs from smaller SMB and ROBO environments to larger SME and enterprise workloads. To me a theme with V6.6 is expanding resiliency, scalability with stability to expand vSAN upmarket as well as into new workloads similar to how vSphere has evolved.

With each new release, vSAN is increasing its feature, functionality, resiliency and extensiveness associated with traditional storage and non-CI or HCI solutions. Overall a good set of enhancements as vSAN continues its evolution looking back just a few years ago, to where it is today and will be in the future. If you have not looked at vSAN recently, take some time beyond reading this piece to learn some more.

Ok, nuff said (for now…).


Greg Schulz – Microsoft MVP Cloud and Data Center Management, VMware vExpert (and vSAN). Author Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press), Resilient Storage Networks (Elsevier) and twitter @storageio. Watch for the Spring 2017 release of his new book “Software-Defined Data Infrastructure Essentials” (CRC Press).

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