When deploying infrastructure, it is important to know two things: current resource needs and that those resource needs will grow. What we don’t always know is in what way the demands for resources will grow. Resource growth is rarely equal across all resources. Storage demands will grow more rapidly than compute, or vice-versa. At the end of the day, we can only make an educated guess, and time will tell if we guessed right. We can, however, make intelligent choices that increase the flexibility of our growth options and give us the ability to scale resources independently. Enter the single processor Dell VxRail P670F.

The availability of the P670F with only a single processor provides more growth flexibility for our customers who have smaller clusters. By choosing a less compute dense single processor node, the same compute workload will require more nodes. There are two benefits to this:

• More efficient storage: More nodes in the cluster opens the door to using the more capacity efficient erasure coding vSAN storage option. Erasure coding, also known as parity RAID, (such as RAID 5 and RAID 6) has a capacity overhead of 33% compared to the 100% overhead that mirroring requires. Erasure coding can deliver 50% more usable storage capacity while using the same amount of raw capacity. While this increase in storage does come with a write performance penalty, VxRail with vSAN has shown that the gap between erasure coding and mirroring has narrowed significantly, and provides significant storage performance capabilities.
• Reduced cluster overhead: Clusters are designed around N+1, where ‘N’ represents sufficient resources to run the preferred workload, and ‘+1’ are spare and unused resources held in reserve should a failure occur in the nodes that make up the N. As the number of nodes in N increases, the percentage of overall resources that are kept in reserve to provide the +1 for planned and unplanned downtime drops.

Figure 1: Single processor P670F disk group options

You may be wondering, “How does all of this deliver flexibility in the options for scaling?” 

 You can scale out the cluster by adding a node. Adding a node is the standard option and can be the right choice if you want to increase both compute and storage resources. However, if you want to grow storage, adding capacity drives will deliver that additional storage capacity. The single processor P670F has disk slots for up to 21 capacity drives with three cache drives, which can be populated one at a time, providing over 160TB of raw storage. (This is also a good time to review virtual machine storage policies: does that application really need mirrored storage?) The single processor P670F does not have a single socket motherboard. Instead, it has the same dual socket motherboard as the existing P670F—very much a platform designed for expanding CPU and memory in the future. 

If you are starting small, even really small, as in a 2-node cluster (don’t worry, you can still scale out to 64 nodes), the single processor P670F has even more additional features that may be of interest to you. Our customers frequently deploy 2-node clusters outside of their core data center at the edge or at remote locations that can be difficult to access. In these situations, the additional data resiliency that provided by Nested Fault Domains in vSAN is attractive. To provide this additional resiliency on 2-node clusters requires at least three disk groups in each node, for which the single processor P670F is perfectly suited. For more information, see VMware’s Teodora Hristov blog post about Nested fault domain for 2 Node cluster deployments. She also posts related information and blog posts on Twitter. 

It is impressive how a single change in configuration options can add so much more configuration flexibility, enabling you to optimize your VxRail nodes specifically to your use cases and needs. These configuration options impact your systems today and as you scale into the future.

Author Information

Author: David Glynn, Sr. Principal Engineer, VxRail Technical Marketing

Twitter: @d_glynn

Get your VxRail learn on with Tech Field Days and ESG

It has been a busy summer with the launch of our Next Gen VxRail nodes built on 15^th Generation PowerEdge servers. This has included working with the fantastic people at ESG and Tech Field Day. Working with these top tier luminaries really forces us to distill our messaging to the key points – no small feat, particularly with so many new releases and enhancements.

If you are not familiar with Tech Field Days, they are “a series of invite-only technical meetings between delegates invited from around the world and sponsoring enterprise IT companies that share their products and ideas through presentations, demos, roundtables, and more”. The delegates are all hand-picked industry thought leaders – those wicked smart people you are following on Twitter – and they ask tough questions. Earlier this month, Dell Technologies spent two days with them: a day dedicated to storage, and a day for VxRail. You can catch the recordings from both days here: Dell Technologies HCI & Storage: Cutting Edge Infrastructure to Drive Your Business.

Of the twelve great jampacked VxRail sessions, if you cannot watch them all, do make time in your day for these three:

• VxRail dynamic nodes – Flexibility for the Future. In short, VxRail without vSAN. Leverage HCI Mesh, or FC SAN storage like PowerStore T or PowerMax, and bring that VxRail LCM goodness to other vSphere clusters in your data center.
• What Does “Seamless Technology Integration” Mean for VxRail? I hate tooting my own horn, but if you want a quick deep dive on where all the storage performance in VxRail is coming from, this is your 22-minute Cliff Notes version.
• Get the Most Out of Your K8s with Tanzu on VxRail This is your crash course about how VxRail can get Tanzu stood up, so you can get Kubernetes at the Speed of Cloud, within your data center.

One more suggestion, if you are new to VxRail, or on the fence about deploying VxRail, tune into this session from Adam Little, Senior Cybersecurity Administrator for New Belgium Brewing, and the reasons they selected VxRail. Even brewing needs high availability, redundancy, and simplicity.

ESG is an IT analyst, research, validation, and strategy firm whose staff is well known for their technical prowess and frankly are fun to work with. Maybe that is because they are techies at heart who love geeking out over new hardware. I got to work with Tony Palmer as he audited the results of our VxRail on 15^th Generation PowerEdge performance testing. Tony went through things with a fine-tooth comb, and asked a lot of great (and tough) probing questions.

What was most interesting was how he looked at the same data but in a very different way – quickly zeroing in on how much performance VxRail could deliver at sub-millisecond latency, verses peak performance. Tony pointed out “It’s important to note that not too long ago, performance this high with sub-millisecond response times required a significant investment in specialized storage hardware”. Personally, I love this independent validation. It is one thing for our performance team to benchmark VxRail performance, but it is quite another for an analyst firm to audit our results and to be blown out of the water to the degree they were. Read their full Technical Validation of Dell EMC VxRail on 15th Generation PowerEdge Technology: Pushing the Boundaries of Performance and VM Density for Business- and Mission-critical Workloads], and then follow it up with some of their previous work on VxRail.

If performance concerns have been holding you back from putting your toes in the HCI waters, now is a great time to jump in. The 3^rd Gen Intel® Xeon® Scalable processors are faster and have more cores, but also bring other hardware architectural changes. From a storage performance perspective, the most impactful of those is PCIe Gen4, with double the bandwidth of PCIe Gen 3 which was introduced in 2012. 

From the OLTP16K (70/30) workload in the following figure, we can see that by just upgrading the vSAN cache drive to PCIe Gen 4, an additional 37% of performance can be unleashed. If that is not enough, enabling RDMA for vSAN nets an additional 21% of performance. One more thing, this is with only two diskgroups… check in with me later for when we crank performance up to 11 with four diskgroups, faster cache drives, and a few more changes.

With OLTP4K (70/30) peak IOPS performance clocking in at 155K with 0.853ms latency per node, VxRail can support workloads that demand the most of storage performance. But performance is not always the focus of storage.

If your workloads benefit from SAN data services such as PowerStore’s 4:1 Data Reduction or PowerMax’s SRDF, then now is a great time to learn about the VxRail Advantage and the benefits that VxRail Lifecycle Management provides. Check out Daniel Chiu’s blog post on VxRail dynamic nodes, where the power of the portfolio is delivering the best of both worlds.

Author: David Glynn, Twitter (@d_glynn), LinkedIn