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How to bootstrap vCenter Server onto a single VSAN node Part 1?

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By now, I am sure you have heard about VMware Virtual SAN (VSAN) and you are probably anxious to give it a spin once the beta becomes publicly available in the very near future. I have been doing some testing in my lab with VSAN, not Nested VSAN, but on actual physical hardware. While getting started, I hit an interesting challenge given my physical hardware configuration and also this being a greenfield deployment.

Let me explain by what I mean by this. In my lab, I have three physical hosts and each contains a single SSD and single SATA drive. Each host has been provisioned with a small 5GB iSCSI boot LUN that is used to install ESXi (this could have also been another local disk or even USB/SD card). Though VSAN itself is built into the VMkernel, the management of the VSAN cluster, configurations and policies are all performed through vCenter Server. So for a greenfield deployment, you would need to first deploy a vCenter Server which would then require you to consume at least one of the local disks. This is the good ol chicken and egg problem!

In my environment, this was a problem because I only have a single SSD and SATA disk and I would not be able to setup a VSAN datastore for all three hosts at once. This meant I had to do the following steps:

  1. Create a local VMFS volume on the first ESXi host
  2. Deploy vCenter Server and then create a VSAN Cluster
  3. Add the two other ESXi host to the VSAN Cluster
  4. Storage vMotion the vCenter Server to the VSAN Datastore
  5. Destroy the local VMFS datastore on first ESXi host (existing VMFS partitions will not work with VSAN) & delete partitions
  6. Add the first ESXi host to VSAN Cluster

As you can see this can get a bit complicated and potentially error prone when needing to destroy VMFS volumes ...

I figured there had to be a better way and I was probably not going to be the only one hitting this scenario for a greenfield and even potentially for a brownfield deployments. In talking to Christian Dickmann, a Tech Lead for the VSAN project, I learned about a really cool feature of VSAN in which you can actually bootstrap vCenter Server onto a single VSAN node! This was possible due to the tight integration of VSAN within the VMkenel and best part about this solution is that it is fully SUPPORTED by VMware. From an operational perspective, this deployment workflow is much easier and intuitive than the process listed above. This also allows you to maximize the use of your hardware investment by running both your core infrastructure VMs as well as your regular workloads all on the VSAN datastore which is great for small or ROBO offices.

In my environment, I start out with a single ESXi 5.5 host which contains a single SSD and SATA disk and I create single VSAN node from that ESXi host and contribute its storage to the VSAN datastore. I then deploy a vCenter Server for which I am using the VCSA (vCenter Server Appliance) for quick and easy deployment. The default policy for VSAN is to automatically ensure there is at least one additional replica of the VM as new ESXi compute nodes join the VSAN cluster.

Once the vCenter Server is online, I can then create a vSphere Cluster and enable it with VSAN and add all three ESXi 5.5 hosts to the vSphere Cluster. This will then contribute all their storage to the VSAN datastore all while the vCenter Server is happily running. Once the other ESXi hosts join the VSAN cluster, we will automatically get replication between the other nodes to ensure our vCenter Server is replicated and of course you can change this policy.

As you can see this is much simpler setup than having to start out with an existing VMFS or even NFS datastore to initially store the vCenter Server and then create the VSAN datstore and migrate the vCenter Server. I also like how I can start deploying my infrastructure with a single ESXi host and then slowly bring in additional ESXi hosts (just make sure you do it in timely fashion as you have a SPOF until then). In part two of this article, I will go into more details on how to configure the single VSAN node and bootstrap vCenter Server. In the meantime, if you have not checked out these awesome articles by some of my VMware colleagues, I would highly recommend you give them a read, especially Cormac's awesome VSAN series!

Here is How to bootstrap vCenter Server onto a single VSAN node Part 2?

If you are interested in testing out VSAN, be sure to sign up for the beta here!

Cormac Hogan

Duncan Epping

Dave Hill

How to quickly setup and test VMware VSAN (Virtual SAN) using Nested ESXi

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Last week at VMworld 2013, VMware announced the release of vSphere 5.5 which includes a variety of exciting new features.  One of the most anticipated feature introduced in this release is VMware Virtual SAN (VSAN) which will be available initially as a public beta. One question that I heard repeatedly throughout the VMworld conference was whether it would be possible to test VSAN in a nested ESXi environment? The answer is absolutely! This is a great way to learn about VSAN and how works from a functional perspective before procuring the necessary hardware.

Disclaimer: Running VSAN in a nested ESXi environment is not officially supported nor is it a replacement for actual testing on actual physical hardware.

Before getting started, I would highly recommend you check out the following resources from my good friend Cormac Hogan which includes a detailed VSAN walk through as well what looks to be an awesome series of articles on how VSAN works:

Requirements:

  • Environment running either vSphere 5.1 or 5.5 and access to the vSphere Web Client.

Configuration:

Nested ESXi VM configured with the minimal resources:

  • 2 vCPU
  • 5GB Memory (ESXi 5.5 now requires a minimum of 4GB vs 2GB as with previous releases but VSAN requires minimum of 5 with recommended 6)
  • 2GB Disk for ESXi 5.5 installation
  • 4GB Disk for an "Emulated" SSD
  • 8GB Disk for HDD

Easy Method:

Instead of having you go through the process of building a Nested ESXi VM with all the prerequisites that includes steps from here and here. I have pre-built a VSAN Nested ESXi VM template (217Kb) that you can just download and import into your environment and being the installation process.

Download either:

and connect to your vCenter Server 5.1 or 5.5 using the vSphere Web Client and import the OVF into your environment (do not use the vSphere C# Client as the import does not persist VHV configuration). Once you have imported the VM, you can then mount the ESXi 5.5 ISO and begin the installation. All three VMDKs have been thin provisioned and you can change the capacity during deployment.

Slightly Harder Method:

If you wish to build the Nested ESXi VM yourself, then you can follow these instructions:

Step 1 - Create a new VM and when you get to the compatibility screen, select either "ESXi 5.1 or greater" or "ESXi 5.5 or greater" depending on the version of vSphere you are running

Step 2 - For the GuestOS select "Other" and "Other (64-bit)"

Step 3 - We will need to customize the following virtual hardware configuration:

  • Change vCPU to 2
  • Click on CPU drop down and enable "Expose hardware assisted virtualization to the guest OS"
  • Change Memory to 4GB
  • Change the initial VMDK to 2GB or whatever value you wish to use for ESXi installation
  • Add second VMDK with 4GB or whatever value you wish to use for "emulated" SSD
  • Add third VMDK with 8GB of whatever value you wish to use for the HDD
  • Click on the VM Options tab at the top and select the "Advanced" drop down box. We will need to add the following entry scsi0:1.virtualSSD = 1 For more details please refer to this article

Step 4 - Click okay to provision the VM and once it has been deployed you will need to re-configure the guestOS to "VMware ESXi 5.x" using the vSphere C# Client for vSphere 5.1 or vSphere Web Client for vSphere 5.5. At this point, you will have the same VM image as in the Easy Method and you are now ready to install ESXi 5.5

When you install ESXi 5.5, you should see the following three disks as shown in the screenshot below, ensure you install ESXi on the 2GB disk:

Prior to enabling VSAN on the particular vSphere Cluster, make sure you enable the new VSAN traffic type on one of your VMkernel interfaces for each of your ESXi hosts, this is required for VSAN communication.

If all the prerequisites have been met, you can now easily enable VSAN by simply checking the VSAN box when editing the vSphere Cluster. In just a few minutes you should see diskgroups automatically created (assuming you selected Automatic mode) consuming both the emulated SSD and HDD and the creation of the vsanDatastore which will be available on all ESXi hosts within that vSphere Cluster.

You can also use the same method for emulating an SSD running in a Nested ESXi to functional test the new VMware Flash Read Cache (vFRC) feature.