Looking for Radically Simple Storage?

Hopefully by now you have heard of Virtual SAN, part of VMware’s Software Defined Datacenter strategy. Currently over 10,000 customers have registered for the beta and it has become a frequent subject in many conversations. So where does it fit in your environment? Do you have a need for lower cost Test/Dev, VDI or remote office environments? Those are great places to get started. Even though it has people’s interest I hear all the time it is only a version 1 but did you know it has been in development for a number of years? Download the beta and give it a try.

If you have been waiting anxiously because you liked what you have seen sign up for the upcoming online event:

Virtual SAN Event March 6

Date: Thursday, March 6, 2014
Time: 10:00 a.m. – 11:00 a.m. PST


VSAN is fully integrated with vSphere and literally has two clicks to storage provisioning (try the hands on lab to see how easy it is). Of course there are some requirements that you need to meet first so take a look at the requirements below:

vSphere Requirements

vCenter Server

VSAN requires at a minimum that the VMware vCenter Server™ version is 5.5. Both the Microsoft Windows version of vCenter Server and the VMware vCenter Server Appliance™ can manage VSAN. VSAN is configured and monitored via the VMware vSphere Web Client and this also requires version 5.5. vSphere

VSAN requires at least three vSphere hosts (in which each host has local storage) to form a supported VSAN cluster. This enables the cluster to meet the minimum availability requirement of at least one host, disk, or network failure tolerated. The vSphere hosts requires at a minimum vSphere version 5.5.

Storage Requirements

Disk Controllers

Each vSphere host participating in the VSAN cluster requires a disk controller. This can be a SAS/SATA host bus adapter (HBA) or a RAID controller. However, the RAID controller must function in what is commonly referred to as pass-through mode or HBA mode. In other words, it must be able to pass up the underlying hard disk drives (HDDs) and solid-state drives (SSDs) as individual disk drives without a layer of RAID sitting on top. This is necessary because VSAN will manage any RAID configuration when policy attributes such as availability and performance for virtual machines are defined. The VSAN Hardware Compatibility List (HCL) will call out the controllers that have passed the testing phase.

Each vSphere host in the cluster that contributes its local storage to VSAN must have at least one HDD and at least one SSD.

Hard Disk Drives

Each vSphere host must have at least one HDD when participating in the VSAN cluster. HDDs make up the storage capacity of the VSAN datastore. Additional HDDs increase capacity but might also improve virtual machine performance. This is because virtual machine storage objects might be striped across multiple spindles.

This is covered in far greater detail when VM Storage Policies are discussed later in this paper.

Solid-State Disks

Each vSphere host must have at least one SSD when participating in the VSAN cluster. The SSD provides both a write buffer and a read cache. The more SSD capacity the host has, the greater the performance, because more I/O can be cached.

NOTE: The SSDs do not contribute to the overall size of the distributed VSAN datastore.

Network Requirements

Network Interface Cards

Each vSphere host must have at least one network interface card (NIC). The NIC must be 1Gb capable. However, as a best practice, VMware is recommending 10Gb NICs. For redundancy, a team of NICs can be configured on a per-host basis. VMware considers this a best practice but does not deem it necessary when building a fully functional VSAN cluster.

Supported Virtual Switch Types

VSAN is supported on both the VMware vSphere Distributed Switch™ (VDS) and the vSphere Standard Switch (VSS). No other virtual switch types are supported in the initial release.

VMkernel Network

On each vSphere host, a VMkernel port for VSAN communication must be created. The VMkernel port is labeled Virtual SAN. This port is used for intercluster node communication and also for reads and writes when one of the vSphere hosts in the cluster owns a particular virtual machine, but the actual data blocks making up the virtual machine files are located on a different vSphere host in the cluster. In this case, I/O must traverse the network configured between the hosts in the cluster.

Before you decide to go out and build your own take a look at the “VMware Virtual SAN Design & Sizing Guide” to get some idea around what size and number of components you need.

Additional resources:

VSAN Product page:

VMware Storage Blog:

VSAN Product walk thru:

VMworld 2013 Session STO4798 Software Defined Storage:

HOL- SDC-1308 Virtual SAN (VSAN) and Virtual Storage Solutions

Cormac Hogan has a great blog with a number of resources on VSAN:


Duncan Epping also has some great info on his blog:



Lastly voting is open for Top vBlog 2014 so get signed up and vote.