VMware Virtual SAN (VSAN) Launched

VMware introduced the revolutionary and disruptive concept of server hardware virtualization which has helped usher in a new era of computing.  This abstraction has provided more management, more automation, more scale, and of course more value.

So who better to introduce a storage array that is hardware agnostic (within the vSphere HCL) than VMware with Virtual SAN (VSAN)?  I’m genuinely intrigued and excited by VSAN and I wanted to briefly share a few reasons why.

Other vendors made been making impressive advances with SDS and offering more capability and value in their offerings, but must of these solutions – even though they may be powered by software – are packaged as hardware (and this isn’t necessarily bad).  Now to be fair VMware VSAN is not technically the first hardware agnostic solution but I suspect that it is the first one to offer mission-critical performance at this scale:


We’ve already seen the trend of more and more storage capabilities being provided by a “storage hypervisor” in several solutions, but VSAN is unique in that it truly is hardware independent.  If your servers are on the VMware HCL (hardware compatibility list) then just add disks and VSAN licenses and you’ve got a SAN.  This dramatically reduces the capital investment required — you’ll still want 10GB switches of course but the rest is software and disks (HDD/SSD).

In this sense VMware VSAN is somewhat of a watershed moment. Yes, there are other SDS solutions (more on this in a future post), but this is the first one that is sold as software only and can perform to the kind of scale noted above. The VMware VSAN team deserves much credit here and it will be exciting to see how this solution is further improved in future releases.


One way VSAN provides strong performance is by using the scale-out model – as you add host nodes with DAS your performance scales out along with it due to the highly parallel nature of the processing  (several vendors such as Nutanix have had success with this model).

VMware surprised us by launching VSAN with support for 32 nodes in a cluster when most of us were expecting only 16 based on the beta program.  With support for 32 node scale-out this immediately positions VSAN as a viable candidate for much more than just the SMB market.


With VSAN you design your vSphere clusters and choose your storage elements (drives and/or SSDs) consistent with your needs and budget.  There is more opportunity to custom tailor your storage solution to meet your specific budget and needs.


VSAN Launch Partners


VMware VSAN is closely integrated into vSphere and includes some of the VVOL concepts which are not yet available for other arrays.  With VSAN you can create storage policies that shield operators from the complexities of constructs like LUNs and RAID levels.  If you want to provision a template or a pre-defined application the end user needs only to select a storage policy (or perhaps only one option has been assigned).  No LUNs have to be created or zoned – VSAN automatically provisions the VMDK from storage pools consistent with the specified storage policies.


Like vSphere, VMware VSAN is a strong CAPEX play meaning that you can significantly reduce the capital investment required to provide storage for your vSphere environment.

Some organizations will choose to continue the business-as-usual model of the “no one got fired for choosing [insert major storage vendor here” variety. But this may be a false sense of safety and may not result in the optimal solution and value.  The storage market is facing disruption and those that successfully navigate this new wave will reap the benefits.

I could talk about these concepts in more detail but I need to save some of it for an upcoming review of the storage market in general (Storage Trends Part 3).  In summary I’m very excited about what VMware VSAN offers and it’s potential in the future as it continues to be enhanced with more SDS capability and for many environments it will likely be worth taking a close look.

General Availability and Pricing for VSAN are expected to be released next week (week of Monday 3-10-2014).  For more information here are a few links:

VMware VSAN Product Page

VSAN Design and Sizing Guide

Duncan Epping’s VSAN articles

Cormac Hogan’s VSAN articles

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