Last week I posted (located here) on new hosts that I setup and deployed in my lab. One goal for the new lab hosts was to work with and get familiar with VMware’s VSAN product while leveraging it in my studies for my upcoming VCAP-DTA exam. Though the exam is based on View 5.2, I needed to upgrade my lab to View 5.3.1 (the minimum supported version of View). While fighting the urge to upgrade the lab to the latest and greatest shiny object, View 6.0, I went to work on getting VSAN deployed. Though I only have two physical hosts, I wanted to find away to setup VSAN and getting running without a 3rd host (whether physical or spoofing it with a virtual host).
Before going further I want to state that the following changes are NOT SUPPORTED and are for obvious reasons not recommended for a production environment. With these changes no “replica’’ virtual machine information is created, so with a lost of one of my hosts that VM and its data are lost. As I am running non-persistent desktops just for testing this is not an issue.
On with the show
With the disclaimer out of the way, lets get to it. As you can see from the screenshot below VSAN has been enabled on the two lab hosts. Each host is providing a single SSD drive for the read/write cache and two SATA magnetic drives for the persistent storage:
With the VSAN Datastore created and presented to each of the hosts I took to the Horizon View administrator console and try to spin up a quick desktop pool. After waiting a few minutes I received an error in vCenter that the replica creation had failed. I took a look at the settings for the desktop pool I created and received the following error:
The challenge is clearly highlighted in the screenshot, VSAN knows that only two hosts participate in the VSAN cluster and a minimum of three nodes are required for a proper configuration. Thinking that I could out smart View/VSAN I logged into the vCenter web client and created a new storage policy and set the “Number of failures to tolerate” to zero and “Force Provisioning” to yes:
With the new storage policy created I attached the policy to my View golden image desktop and tried to provision the desktop pool again. Second try, same result. Received the same message as the screen shot above, View/VSAN knows I am running with only two nodes. Keeping score, VSAN 2, Jason 0.
At this point I took to Google to do some research and see if anyone has tried this or ran into a similar situation. While the research was light on folks trying to run a two node VSAN cluster (not surprising, again NOT SUPPORTED) I did find an article that covered VSAN operability with VMware View 5.3.1:
Reading through the KB article I stumbled across the answer I was looking for under the Virtual SAN Storage Policy Profiles section of the article:
With Horizon View 5.3.1, there is no need for any user action associated with the default policy. The policy applies to both linked-clone desktop pools and full-clone desktop pools. The default policy for all virtual machines using the Virtual SAN datastore is as follows:
- Stripes: 1
- Resiliency: 1
- Storage provisioning: Thin
Even though I created a Storage Policy VSAN with View 5.3.1 leverages the “Default Policy” out of the box for virtual machines. This can be seen by running the following command via a console session on your ESXi host:
esxcli vsan policy getdefault
The output from the command is displayed below:
From the screenshot we can see that for each of the “Policy Class” attributes the setting “hostFailurestoTolerate” is configured for 1 (one), which in my configuration is not supported. Also the other option to note is the “forceProvisioning” set to 1 (one). Mentioned in the VMware KB article is an example of how to manipulate the default policy via ESXCLI commands.
I went to work and set the “hostFailuresToTolerate” and “forceProvisioning” options to 0 (zero) and 1 (one) respectively for each of the Policy Classes as seen by the screenshot below:
After the changes were made I again tried to provision my test desktop pool with VM’s to the VSAN Datastore. This time with a little more success, though it looks like I need to update my View Agent in the golden image.
Thanks for reading and post questions or comments below!