Introduction:

vSAN continues its journey of growth with more than 7,000 customers have chosen to entrust their most important workloads to vSAN. To support this journey, we are committed to work with our partners and enable the next generation hardware platform for our mutual customers.

Composable infrastructure is the next generation platform customers are adopting and today we are very glad to announce that HPE Synergy - the first composable infrastructure - is now certified for vSAN. This is a huge milestone towards helping our mutual customers run traditional and next generation workload.

You can find the HPE Synergy on vSAN VCG here and here.

Traditional HCI versus Composable HCI

The definition of composable infrastructure described in next section. But before we get to that, the main fundamental question we need to ask and understand is that “can composable infrastructure be used for HCI deployment”? The answer is “Yes”. Here is why:

The fundamental difference is disaggregated compute and storage for composable infrastructure. Traditional HCI brings in the capability of scaling out compute and storage together as a block as you grow. But workloads demand more flexibility. The demand is to scale-out compute and storage independently as need be by retaining the benefits of HCI. Composable infrastructure brings in that element in HCI world.

What is composable infrastructure?

Composable infrastructure has three main capabilities: software defined intelligence, a fluid pool of resources, and a unified API. Fluid resource pools enable the infrastructure to meet each application’s changing needs effortlessly by allowing for the composition and recomposition of single blocks of disaggregated compute, storage and fabric infrastructure. Its software-defined intelligence simplifies operational activities for IT admins by allowing for more automation and template driven workloads. A unified API provides a single management interface to integrate operational silos and eliminate complexity. This new class of unified, two-mode infrastructure facilitates the move to a continuous service and application delivery model and enables applications to be updated as needed, rather than just once or twice a year.

HPE Synergy:

So what does it look like? HPE Synergy is a 10U box, called a frame, which has 12 half height modular bays, which can also be configured as 6 full height bays. These bays can be populated with up to twelve servers. Up to four storage modules can be added within the frame as well, with up to 40 small form factor (SFF) drives per storage module. In the below section "Few vSAN Deployment Choices for HPE Synergy", we will discuss a few possible deployment configuration of HPE Synergy from vSAN perspective.

Why Synergy on vSAN?

HPE Synergy is both an evolution from today’s HPE BladeSystem and the first in the new category of composable infrastructure, and you can learn more about it here. Other than that, here are couple of key benefits HPE Synergy brings which makes it a perfect choice for vSAN:

Disaggregated Storage and Compute:

Companies are becoming more dynamic and it is hard to plan ahead and predict the nature of workload the business will require. They demand a platform which can grow dynamically (both compute and storage).The biggest advantage of this platform is storage and compute can scale independently. For our chosen configuration scenario (discussed in possible deployment choices section below), the single HPE Synergy frame can hold up to 80 SFF (2.5”) drives or up to 10 compute servers (see the example deployment section below). You can start small (with 3 compute servers and partially populating one storage module) and based on the demand of your workload, you can either add compute or storage. This is a huge benefit in today’s business environment. It not only saves upfront expenditure by avoiding overprovisioning but provides the flexibility of scaling; e.g. if a new workload demands only compute, you can scale compute modules in the frame and vice versa.

Indeed, you can build up to a 10-node vSAN cluster with up to 40 drives within a single frame (in-a-box) and extend it by adding additional frames as business demand grows.

Single Infrastructure for any workload:

Enterprises are expected to adopt a strategy that maintains existing infrastructure for traditional applications and creates a different infrastructure and tools for new cloud-native and mobile applications. vSAN runs both traditional and new generation use cases in the enterprise today. We learn it about every day by talking to our customers and seeing their vSAN deployments. The following diagram depicts what use cases organizations are running today on vSAN.

As you can clearly see the expectation from the infrastructure platform running vSAN is that it should be able to accommodate “bimodal computing” (traditional and new generation workloads). HPE Synergy architectural and management solution addresses both traditional and emerging business applications thus helping enterprises run vSAN use cases in a single infrastructure.

High-Speed Interconnect between Frames:

Because HPE Synergy uses a master-satellite topology for Ethernet connection between frames in the same logical enclosure server to server data traffic – even between servers in different frames - is served by high speed Ethernet connections at up to 20Gb/s without the latency introduced by top of rack switching. This is a great benefit when a large vSAN cluster spans across frames.

Why Synergy is a good fit for vSAN?

In HPE Synergy; the frame is the base infrastructure that pools resources of compute, storage, fabric, cooling, power and scalability. One of the important elements in a frame is that the local disks storage are only accessible inside a single frame. It means all disks need to be presented to compute servers within the same frame. The fundamental of vSAN is that it aggregates all local storage disks available on the hosts (compute servers) into a single datastore shared by all compute servers. In case of traditional rack servers, the compute and storage do not scale independently. But with HPE Synergy, you can achieve the same aggregation by scaling storage and compute separately. This makes it a perfect fit for HCI solutions like vSAN.

A Few vSAN Deployment Choices for HPE Synergy:

There are numerous possibilities of composing and recomposing the compute servers and storage modules in an HPE Synergy platform for vSAN within a single frame as well as across frames for a single vSAN cluster. Indeed, the choice is nearly infinite.

But I would, however, put forward three fundamental configurations from vSAN deployment perspective within a single frame (fully populated) and believe that most of the possibilities are extensions of that in some way.

One Frame with 1x Storage Module {D3940 (12 drives)} and 3x Compute Servers {SY 480} half height servers:

Each of these compute servers are configured with four drives within a single disk group (1 cache + 3 capacity) per server. The optimal choice would be to use SAS drive as cache tier and SATA drives as a capacity tier.

One Frame with 2x Storage Module {D3940 (80 drives)} and 8x Compute Servers {SY 480} half height servers:

Each of these compute servers are configured with eight drives within two disk groups (1 cache + 4 capacity) per group. The optimal choice would be to use SAS drive as cache tier and SATA drives capacity tier.

One Frame with 1x Storage Module {D3940 (40 drives)} and 10x Compute Servers {SY 480} half height servers:

Each of these compute servers are configured with four drives within a single disk group (1 cache + 3 capacity) per server. The optimal choice would be to use SAS drive as cache tier and SATA drives as a capacity tier.

I would put below table as an example for three possible combinations for all flash vSAN deployment on Synergy:

Example Table of Possible vSAN Configuration within a Single Frame

Just to reiterate again, vSAN requires only three compute servers to begin with. The above configurations are just examples where the single frame is completely populated. As this new generation hardware gets deployed more and more, we will learn more about how users like to configure it.

How HPE Synergy Compares with HPE BladeSystem:

There is a nice document available in HPE site and you can read it here. However, I would like to highlight the comparisons in the document here:

What Use Cases is HPE Synergy Not Meant for Today?

Though HPE Synergy covers a large number of use cases within a single infrastructure, there are a few cases where it may not be a good candidate.

Applications that require NVMe drives in the Storage Module: There may be niche workloads that require NVMe device performance in the storage module. Today’s HPE Synergy platform does not have NVMe support on the storage module because it uses a SAS interface instead of a native PCIe. However, HPE Synergy does offer NVMe support on the server modules that could potentially be used as cache tier device for vSAN. Very Large Capacity DAS Storage Workload: As we are aware that 3.5” drives provide larger capacity point than 2.5” drives. Today’s HPE Synergy storage module does not support 3.5” drives. High capacity workloads can still be serviced using a SAN, but there are a few DAS oriented applications which require very large capacity and primarily do not need any performance. In such cases, Synergy may not provide the most cost effective storage solution, if any application requires both performance and dense storage, Synergy is still a platform of choice for such workload.

Conclusion

As organizations adopt this new generation platform to run their traditional and next generation applications, VMware is committed to working closely with partners like HPE to certify this for vSAN.

HPE Synergy disaggregated storage and compute is a great fit for HCI allowing customers to grow their environment based on demand. If you are using HPE Synergy for your workload, feel free to share your configuration and deployment experience in the blog comments below.

For any questions on vSAN hardware, please reach out to vSAN Hardware PM vsan-hcl@vmware.com.

To learn more about vSAN, visit VMware vSAN

To learn more about HPE Synergy, visit HPE Synergy