Symmetric Multi-Processing Fault Tolerance (SMP-FT) has been a long-awaited feature by many VMware customers. With the release of vSphere 6.0, the SMP-FT capability is now finally available and if you want to try out this new feature and see how it works from a "functional" perspective, you can easily do so by running it in a Nested ESXi environment. SMP-FT no longer uses the "record/replay" capability like its younger brother Uniprocessing Fault Tolerance (UP-FT). Instead, SMP-FT now uses a new Fast Checkpointing technique which not only improves the overall performance of its predecessor but also greatly simplifies and reduces additional configurations when running in a Nested ESXi environment.
Disclaimer: Running SMP-FT in a Nested ESXi environment does not replace or substitute actual testing of physical hardware. For any type of performance testing, please test SMP-FT using real hardware.
- pESXi host running either ESXi 5.5 or 6.0
- vCenter Server 6.0
- 2 x Nested ESXi VMs running ESXi 6.0 (vHW9+)
- Shared storage for the Nested ESXi VMs
Step 1 - Created a Nested ESXi VM using guestOS type "ESXi 5.5/6.0 or later". You will need at least 2 vCPU or greater, 4GB of memory or greater for the installation of ESXi and most importantly, a VMXNET3 network adapter. The reason a VMXNET3 adapter is required is that SMP-FT has a requirement for 10Gbit network connection and the VMXNET3 driver can simulate a 10Gbit connection for a Nested ESXi VM. For further instructions on creating a Nested ESXi VM, please take a look at this article. If you are unable to add VMXNET3 adapter, you may need to first change the guestOS type to "Other 64-bit", add the adapter and then change the guestOS type back.
Step 2 - Install ESXi 6.0 on the Nested ESXi VM and ensure you also have a vCenter Server 6.0 deployed if you have not done so already and add your Nested ESXi instances to a new vSphere Cluster which has vSphere HA enabled.
Step 3 - You will need to enable both vMotion and Fault Tolerance traffic type for the VMkernel interface that you wish to run FT traffic across.
Step 4 - At this point, you can create a real or dummy VM and power it on. Once you have the powered on VM, you can now enable either UP-FT or SMP-FT by right clicking and selecting "Enable Fault Tolerance".
As you can see from the screenshot above, I have successfully enabled FT on a VM with 4vCPU running inside of a Nested ESXi VM, how cool is that!? Hopefully this will help you get more familiar with the new SMP-FT feature when you are ready to give it a real spin on real hardware 🙂
Note: Intel Sandy Bridge is recommended when using SMP-FT (real physical hardware) but if you have older CPUs, you enable "Legacy FT" mode by adding the following VM Advanced Setting "vm.uselegacyft" to the VM you are enabling FT on.