VMware vSAN is a compelling technology, but if you don't have the resources to fulfill its requirements, you can...
mimic the required host hardware in a test vSAN lab with VMware Workstation.
This vSAN lab isn't designed for production -- it won't be performant or redundant -- but it'll enable experimentation.
The first step to setting up this vSAN lab is to create three virtual ESXi hosts. Each virtual host should have the following specifications: 16 GB of RAM, a 20 GB OS disk, a 135 GB mechanical storage disk, a 35 GB solid-state drive (SSD) flash disk and two network connections for traffic -- one for ESXi traffic and one for vSAN traffic. You can use bridged networking to achieve this. Ideally, the traffic would be isolated, but this is only a test lab.
Configure virtual hosts for the vSAN lab
Use Workstation to configure three identical virtual hosts. Once each node is built, configure the IP address and domain name system (DNS) for each of the three servers.
Previously, this process required significant interaction with the command line, but that is no longer necessary.
Walk through the ESXi host installation on the 20 GB disk. Then, configure the first network controller with an appropriate IP configuration that's also in the DNS. Repeat these steps for the other two hosts.
Once those steps are complete, run the vCenter UI installation wizard as you would for a normal vCenter installation. Select the Install option.
Click through the Introduction and the End-user license agreement. Select integrated PSC from the Select deployment type menu. Next, use the information from the host setup to configure the host on which you'll be installing vCenter.
Follow items four through seven as seen in Figure B.
On the eighth item -- Configure network settings -- select Enable thin disk mode, and then choose Install on a new Virtual SAN cluster containing the target host, as seen in Figure C.
The options will then update, and you will be able to specify the new vSAN-enabled data center and cluster names.
Configure storage items
First, make sure to tick the vSAN box.
The next page is critical. Each vSAN-enabled node needs at least one flash-fronted disk and a storage disk. If you're using hard disk drives (HDD) rather than SSDs, you can override this. Mark the small 35 GB disk as flash and the 135 GB disk as an HDD.
Configure the vCenter networking settings, review them and click Finish. This will take several minutes to complete.
VCenter will then be deployed. You should see a setup similar to the one shown in Figure E. Don't worry about the displayed errors because the vSAN cluster setup is not yet complete.
The next step in the creation of the vSAN lab is to add the licenses. You'll need licenses for vCenter, the hosts and vSAN. You can use the Licensing tool in the vSphere main menu to add and install them.
You can now pull in two additional hosts. Right-click the Virtual SAN cluster and select Add Host. Fill in the details of each host and go through the wizard for each additional host.
Configure the vSAN network
For the sake of simplicity, this example will show the creation of a standard switch. Take each host in turn and navigate to the VMkernel adapters tab.
Click the add network adapter icon; it's the globe with the green plus sign. When the wizard opens, select VMkernel adapters and move onto the next page. Select Create a Standard Switch.
Click the plus icon. It will show the available adapters. Select the appropriate adapter and click OK. In the Enabled services section, tick the vSAN option. Give it a useful network label, such as vSAN.
On the next page, use an available IP for the VMkernel IP settings and the appropriate subnet. Review the settings and click Finish.
Repeat this for the other hosts. Ensure that the network label is the same across all the hosts or you'll run into connectivity issues. Select the Health tab before navigating to the vSAN cluster.
Click Retest, which appears as an option after selecting a test result. Your setup should then resemble the one shown below. The red data error is due to only having one copy of the data store.
Mimic flash storage
Open each additional host. Navigate to Configure, select the disk and press the F key. Click Yes in the warning box.
Create disk redundancy by selecting Virtual SAN Cluster > Configure > Disk Management > Create disk group -- the second icon from the left under Disk Groups.
Select the smaller 35 GB disk -- the one you previously marked as flash -- in the cache tier. Tick the flash disk and the disk in the capacity tier. Repeat this process for each host.
The redundancy is now configured. It might take a few minutes to sync across the faux vSAN cluster. You can monitor the synchronization in the Resyncing Components tab.
To test resiliency, migrate the original vCenter appliance to a separate host and shut down the host. It should stay up without issue. This will require you to enable vMotion on the first VMkernel port.
Once the sync is complete, run a retest of the vSAN's health. The vSAN cluster should go from red to yellow.
The vSAN cluster will stay yellow due to a number of items you can't fix in the virtual environment of this vSAN lab. You can manually set them to green if you wish.