Introduction to VMware vSAN

VMware Virtual SAN, or new name VMware vSAN, has been around since August 2013. Back then it was indeed called Virtual SAN, today is it is officially known as vSAN, but that is what most people used anyway. In this post I will provide a generic introduction to vSAN which is up to date and covers all that VMware vSAN is about up to the current version of writing, which is VMware vSAN 6.6.


VMware vSAN is enterprise-class storage for hyper-converged infrastructure (HCI). Native to the VMware vSphere hypervisor, vSAN delivers flash-optimized, secure storage. It utilizes commodity x86 server components to lower costs up to 50% versus traditional server and storage array architectures. VSAN is a software-based distributed storage solution that is built directly in the hyper-visor. Although not a virtual appliance like many of the other solutions out there, a VSAN can best be thought of as a kernel-based solution that is included with the hypervisor. Nevertheless, with VSAN there is no need to install anything other than the software you are already familiar with: VMware vSphere.


VMware vSAN is fully integrated with VMware vSphere. If you know how to enable HA and DRS, then you know how to configure vSAN.

vSAN is built on
industry-standard x86 servers and
components that help lower TCO by
up to 50% versus traditional storage.

VSAN is about simplicity, and when we say simplicity, we do mean simplicity.




Here are some of the benefits of a solution like vSAN, some key selling points:

  • Software defined – Use industry standard hardware, as long as it is on the HCL you are good to go!
  • Flexible – Scale as needed and when needed. Just add more disks or add more hosts, yes both scale-up and scale-out are possible.
  • Simplicity – Ridiculously easy to manage! Ever tried implementing or managing some of the storage solutions out there? If you did, you know what I am getting at.
  • Automated – Per virtual machine and per virtual disk policy based management. Yes, even VMDK level granularity. No more policies defined on a per LUN/Datastore level, but at the level where you need it!
  • Hyper-Converged – It allows you to create dense / building block style solutions!


VMware vSAN allows presenting locally attached storage (SSD and HDD) to create clustered datastore. VMware vSAN is a software feature is built into the hypervisor. To be able to leverage VMware vSAN, you’ll need to associate at least one HDD and one SSD in each of the servers participating in the vSAN cluster, where the SSD don’t contribute to the storage capacity. The SSD are doing just read caching and write buffer. The aggregation of HDDs from each server in the vSAN cluster forms a single vSAN datastore. This means that when your cluster grows from a compute perspective, your datastore will typically grow with it.  vSAN pools together server-attached storage to provide a highly resilient shared datastore suitable for any virtualized workload, including use cases:

  • Virtual desktops: Scale-out model using predictive and repeatable infrastructure blocks lowers costs and simplifies operations
  • Test and dev: Avoids acquisition of expensive storage (lowers total cost of ownership [TCO]), fast time to provision
  • Management or DMZ infrastructure: Fully isolated resulting in increased security and no dependencies on the resources it is potentially managing.
  • Disaster recovery target: Inexpensive disaster recovery solution, enabled through a feature like vSphere Replication that allows you to replicate to any storage platform
  • Production / Business Critical Workloads


To conclude some of the key main features and capabilities of vSAN :

  1. Flash-Optimized
  2. Deduplication and Compression
  3. Erasure Coding
  4. vSAN Encryption
  5. Stretched Clusters with Local Protection
  6. VM-centric policy-based management

and many more to disscus on other future post. That more or less covers the basics of the great VMware vSAN product. Thanks for having time to have a look.


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