Why I love VSAN!

I receive a lot of questions about VSAN, how it relates to PernixData FVP and if it will impact PernixData in any way.

In my opinion VSAN corroborates the architectural shift away from monolithic storage designs. The move away from storage arrays being the natural object to provide both storage performance and capacity to the virtual infrastructure. It’s another voice telling that there are different ways of providing storage services to your virtual infrastructure. And its great to see many people reconsidering the current design paradigm. And thats what I love about VSAN, now let's take a closer look at the solutions both products provide, their similarities and their differences.

VSAN is similar to PernixData from a design perspective, providing a scale out solution in the compute layer. Both PernixData FVP and VSAN operate at the correct place, at the hypervisor kernel level. By operating at kernel level, both solutions scale out natively at kernel and cluster level, reduce management overhead and provide operation simplicity.

True scale out storage performance
Scale out should be applied where it’s required and the natural layer is the compute layer. As new workloads are introduced, architects look at the compute layer to expand their pool of compute resources, CPU and memory. The missing part up to this point was storage performance. With the success of acceleration platforms such as FVP it is clear that storage performance should be considered as an integral part of the compute layer when designing your environment. Up to now, buying boatloads of capacity with the goal to provide performance was considered to be storage scale out. By placing a clustered solution that harness the power of flash provides the correct tool for the job at the correct place. Storage arrays can still be used for what they were designed for initially, storing data and providing other data services such as replication and snapshotting.

Architecture-FVP Basic Cluster performance scale out

Where both solutions differ
The reason why VSAN does not impact FVP directly is that VSAN provides a persistent data store layer to store virtual machines. Using VSAN either forces you to move the current virtual machines from your current storage array or place new virtual machines on this new datastore.


FVP does not create a persistent storage layer. It does not require you to change the configuration of current virtual machines and new virtual machines are still stored on the storage array.

FVP decouples the performance requirements from the capacity requirements from storage arrays. This means that the path to the performance layer is short, where it matters (application to flash resources), and the path to the storage layer is longer which becomes transparent to the application.

FVP leverages server flash and clustered services to provide storage performance where it belongs; at the compute layer.

Frank Denneman

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2 Responses

  1. Arun says:

    Do you have performance metrics b/w VSAN and Pernix. ?

  2. Rick Vanover says:

    This is like distinguishing between Yellow and Brown Mustard. On a sandwich they are effectively satisfying the same need. Will be hard for users to consume this differencing stuff.