Yellow Bricks

by Duncan Epping

ready node

#113 – Procuring hardware for a vSAN based VCF infrastructure – featuring John Nicholson!

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I’ve been on the Virtually Speaking podcast several times, so it was time to invite one of the hosts to the Unexplored Territory Podcast and discuss his favorite topic, hardware configurations, and the bill of materials! John Nicholson goes over all the ins and outs of procuring new hardware and talks about ordering components for existing hardware. We discuss NICs, Switches, Ready Node configurations, Emulated Ready Node configurations, NVMe devices, and much more.

Especially in todays world of ever increasing memory prices, and difficulty to procure hardware, the suggestions John makes around re-using existing hardware with vSAN ESA are very valid. Also, the use of Memory Tiering is definitely something every customer should consider. But before I share all the nuggets, just listen to the episode on Spotify (bit.ly/4r66flp), Apple (apple.co/4raF5Kj), the embedded player below, or watch it on Youtube.

During the discussion, various blogs and videos were mentioned, make sure to check those as well!

vSAN ReadyNode emulated configurations? What are those?

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Last week Pete Koehler dropped a bomb on us when he blogged about vSAN ReadyNode emulated configurations. Since then I had a few folks asking what this exactly is. It is fairly simple, some vendors have special SKUs for ReadyNodes, which doesn’t always make configuring a ReadyNode to the desired specifications based on the minimum requirements for vSAN ESA and the supported components. SAY WHAT?

Well just imagine you are a Dell shop and you want to use the R750. You simply check if the R750 is listed on the VCG, you list the minimum CPU spec and you go from there based on the minimum (and maximum) specifications for vSAN ESA and based on your workload profile. Just as an example, the minimum specifications for vSAN ESA are now as follows with the introduction of the vSAN AF-0 ReadyNode configuration:

  • Minimum of 16 cores Intel or AMD
    • For example: 2 x Intel Xeon® Gold 6334 3.6G, 8 cores
    • Or: 1 x AMD EPYC 9124 16C 200W 3.0GHz Processor
  • Minimum of 128GB memory
  • Minimum of 10GbE
  • Minimum of 2 NVMe Devices (as listed on vSAN VCG) and 3.2TB per host

Now that we know what those minimums are, I could simply go to the Dell website and spec a Dell R750 Server as desired. This server could have for instance:

  • 2 x Intel® Xeon Gold 6342 2.8G, 24 cores
  • 256GB memory
  • 25GbE networking
  • 6 x Dell Ent NVMe CM6 RI 3.84TB

Even though it is not on the list as a ReadyNode configuration, this configuration would be supported as all the components are certified, and the server itself is also certified as a vSAN ReadyNode platform, and we are following the guidelines as documented in the vSAN ESA RN KB.

I hope this helps those who are going through the process of procuring hardware for vSAN ESA.

vSAN ESA ReadyNode configurations are more flexible than you think!

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I had a discussion at the Dutch VMUG yesterday about the ReadyNode configurations for vSAN ESA. The discussion was about how difficult it was to select a host and customize it. It was then that I realized that most people hadn’t noticed yet that there is an easier method (or lifehack as my kids would say) when it comes to selecting your server model. How does that work? Well, let me show you!

First, let’s take a look at the vSAN ESA ReadyNode Hardware Guidance Table. The table below shows you what the node capacity is for each profile from a storage, CPU, memory, and networking perspective.

Now if you look at the table you will see that as the “profile” number goes up, so does the capacity for each of the various components. This is actually what provides you with a lot of flexibility in my opinion. If we take Dell as an example, but the same applies for most vendors on the current list, and we select “vSAN-ESA-AF2” and look at the list of options we see the following:

  • PowerEdge R650
  • PowerEdge R6515
  • PowerEdge R750
  • PowerEdge R7515

Now, if we look at “vSAN-ESA-AF8” next, which is the highest profile, we see that we only can pick 1 server model, which happens to be the PowerEdge R750. If we then look at the difference between the hosts selected for each profile a few things stand out:

  • vSAN-ESA-AF2 has an Intel Xeon Silver 4314, while vSAN-ESA-AF8 has a Platinum 8358
  • vSAN-ESA-AF2 has 512GB, while vSAN-ESA-AF8 has 1024GB
  • vSAN-ESA-AF2 a 25Gbps NIC, while vSAN-ESA-AF8 has a 100Gbps NIC
  • vSAN-ESA-AF2 has five 3.2TB NVMe devices while vSAN-ESA-AF8 has twenty-four 3.2TB devices

Now if I look at the KB article which explains what you can, and cannot change, something stands out, most of the components can be modified/customized. For instance, for CPU you can go to a higher core count and/or higher base clock speed! For memory, you can go up, same for storage devices (as long as you stay within supported limits), etc etc.

In other words, what is the difference between a vSAN-ESA-AF2 and a vSAN-ESA-AF8? Basically the expected workload, the performance, the capacity. This ultimately results in a different configuration. Nothing, at this point in time, stops you from selecting the “lowest” vSAN ReadyNode Profile and spec it as an “AF4”, “AF6” or “AF8” from a CPU stance, or from a storage/memory capacity point of view. If you want to have some more flexibility, try selecting a smaller profile, select the host type, and increase the resources/components where needed!

When you start exploring the options it may seem complex, but when you look more closely you will quickly realize that it actually isn’t that complex, and that it actually provides you with a lot of flexibility, as long as you stick to the rules and pick supported components!

Virtual SAN Ready Nodes taking charge!

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Yes that is right, Virtual SAN Ready Nodes are taking charge! As of today when you visit the VMware Compatibility Guide for Virtual SAN it will all revolve around Virtual SAN Ready Nodes instead of individual components. You may ask yourself why that is, well basically because we want to make it easier for you to purchase the hardware needed while removing the complexity of selecting components. This means that if you are a Dell customer and want to run Virtual SAN you can simply select Dell in the VMware Compatibility Guide and then look at the different models there are of the different sizes. It is very easy as can be seen in the screenshot below.

virtual san ready nodes

Traditionally there were 3 different sizes for “Server Virtualization”, but with the full overhaul of the VSAN VCG a new size was added. The naming of the sizing has also changed. Let me explain what it looks like now, note that these “sizing profiles” are the same across all vendors so comparing HP to Dell or IBM (etc) was never easier!

New NameOld Name
HY-2Hybrid Server Low
HY-4** new **
HY-6Hybrid Server Medium
HY-8Hybrid Server High
HY-8Hybrid VDI Linked Clones
Hybrid VDI Full Clones
AF-6All Flash Server Medium
AF-8All Flash Server High
AF VDI Linked Clones
AF VDI Full Clones

The new model introduced is HY-4 Series, the reason this model was introduced is because some customers felt that the price difference between HY-2 and H&-6 was too big. By introducing a model in between we now cover all price ranges. Note that it is still possible when selecting the models to make changes to the configuration. If you want model HY-2 with an additional 2 disks, or with 128GB of memory instead of 32GB then you can simply request this.

So what are we talking about in terms of capacity etc? Of course this is all documented and listed on the VCG as well, but let me share it with you here also for your convenience. Note that performance and VM numbers may be different for your scenario, this of course will depend on your workload and the size of your VMs etc.

ModelCPU / MemStorage CapStorage PerfVMs per node
HY-21 x 6 core / 32GB2TB4000 IOPSUp to 20
HY-42 x 8 core / 128GB4TB10K IOPSUp to 30
HY-62 x 10 core / 256GB8TB20K IOPSUp to 50
HY-82 x 12 core / 348GB12TB40K IOPSUp to 100
AF-62x12 core / 256GB8TB50K IOPSUp to 60
AF-82x12 core / 348GB12TB80K IOPSUp to 120

In my opinion, this new “Ready Node” driven VMware Compatibility Guide driven approach is definitely 10 times easier then focusing on individual components. You pick the ready node that comes close to what you are looking for, provide your OEM with the SKU listed and tell them about any modifications needed in terms of CPU/Mem or Disk Capacity. PS: If you want to access the “old school HCL” then just click on the “Build Your Own based on Certified Components” link on the VCG page.