Performance at a glance:
User experience is everything. In today’s world, fast and intuitive applications are a necessity, and anything less might be labeled slow and not very useful. Once an application is labeled slow, it’s hard to change that impression with end users. Thus, architecting a system for performance is a key consideration in ensuring a good application experience.
In this blog, we explore performance capabilities of Dell EMC Solution for Microsoft Azure Stack HCI built using the Dell EMC R640 S2D Ready Nodes. Storage Spaces Direct or S2D is part of Azure Stack HCI and enables customers to use Azure Stack HCI certified HCI nodes with locally attached drives to create high-performance and high-availability distributed storage. Along with Hyper-V, Software Defined Networking is part of Windows Sever 2019 and Windows Admin Center (WAC). Azure Stack HCI enables the IT organization to run a hybrid virtualized infrastructure with connectivity to Azure cloud services.
For customers who have standardized on Hyper-V, Azure Stack HCI is a compelling solution given all the needed features are included in the Windows Server 2019 Datacenter Edition.
Key benefits of Dell EMC Solution for Azure Stack HCI include:
Storage Spaces Direct enables a high performance storage infrastructure that utilizes the capabilities of Flash and Non-Volatile Memory Express (NVMe) drives along with RDMA Network Cards and network infrastructure to provide both high transactional and throughput performance along with fault tolerance and distributed software resiliency.
Database and other storage-intensive applications could benefit from the faster NVMe drives. NVMe is an open logical device specification that has been designed for low latency and internal parallelism of solid-state storage devices. The result is a significant boost in storage performance because data can be accessed faster and with less I/O overhead.
In our labs, we created an Azure Stack HCI cluster consisting of four Dell EMC R640 S2D Ready Nodes. Each HCI node had two Intel 6248 2nd Gen Intel® Xeon® Scalable processors, ten Intel DC P4510 Intel NVMe drives, and one Mellanox CX5 dual-port 100 GbE adapter. Networking between the nodes consisted of two Dell EMC PowerSwitch S5232 switches that support up to thirty-two 100 GbE ports. Our goal was to drive simplicity in the configuration while showing performance value.
We used Storage Spaces Direct three-way mirroring because this configuration offers the greatest performance and protection. Protection does have a cost in terms of capacity. The capacity efficiency of a three-way mirror is 33 percent, meaning 3 TB equates to 1 TB of usable storage space. The data protection benefit with three-way mirroring is that the storage cluster can safely tolerate at least two hardware problems—for example, the loss of a drive and server at the same time. The following diagram is a simple representation of the four-node performance configuration of the Storage Spaces Direct cluster.
Figure 1: Azure Stack HCI Cluster with 4 Dell EMC R640 Nodes
We ran VM Fleet on the storage cluster to test performance, and the results were impressive! Here is the first test configuration:
Thus, this VM Fleet test used 4 KB block sizes, 100 percent reads, and a random-access pattern. Each node had 20 VMs and each VM used 40 GB of storage on the S2D cluster. This configuration achieved 2,953,095 IOPS with an average read latency of 242 microseconds. A microsecond is equal to one-millionth of a second. This is the kind of performance that can really accelerate online transaction processing (OLTP) workloads and make enterprise applications highly responsive to the end users.
We also tested a 100 percent random-write workload on the storage cluster. All the VM Fleet configuration settings remained the same, except the write ratio was 100. With 100 percent writes, the storage cluster achieved 818,982 IOPS at an average write latency of 4 milliseconds. We could have been less aggressive in our internal tests and delivered even lower write latency, but the goal was to push the storage cluster in terms of performance. Both these tests were done internally in our Dell EMC labs, and it’s important to note that results will vary.
Figure 2: Summary of internal test findings for 100 percent read and write workloads for IOPS and latency
Some applications, such as business intelligence and decision support systems, and some analytical workloads are more dependent on throughput. Throughput is defined by the amount of data that is delivered over a fixed period. The greater the throughput the more data that can be read and the faster the analysis or report. Our labs used the following VM Fleet configuration to test throughput:
Each node had 20 VMs and each VM used 40 GB of storage on the S2D cluster.The throughput test configuration uses larger blocks at 512 KB, 100 percent reads, and a sequential read pattern that is like scanning large datasets. The storage cluster sustained 63 gigabytes per second (GB/s). This throughput could enable faster analytics for the business and provide the capability to make timely decisions.
We also ran the same test with 100 percent writes, which simulates a data load activity such as streaming data from an IoT gateway to an internal database. In this test case, the storage cluster sustained a throughput of 9 GB/s for writes. Both the read and write throughput tests show the strength of this all-NVMe configuration from Dell EMC.
Figure 3: Summary of internal test findings for 100 percent read and write workloads for throughput
If performance is what you need, then Dell EMC can use NVMe technology to accelerate your applications. But flexibility is another factor that can be equally important. Not every application requires high IOPS and very low latencies. Dell EMC offers an expanded portfolio of Storage Spaces Direct Ready Nodes that can meet most any business requirements. A great resource for reviewing the Dell EMC Storage Spaces Direct options is the Azure Stack HCI certification pages. The following table summarizes all the Dell EMC options but doesn’t contain CPU, RAM, and other details that can be found on the certification pages.
R440 S2D RN
R640 S2D RN
R740xd S2D RN
R740xd2 S2D RN
All Flash (All-NVMe)
All Flash (SSD)
Hybrid (NVMe + HDD)
All Flash with Persistent Memory (Intel Optane DC)
Hybrid (NVMe AIC + HDD)
Hybrid (SSD + HDD)
The Dell EMC S2D Ready Nodes can be configured to ship with factory installed Microsoft Windows 2019. Not only this provides a simplified deployment experience, but also end to end technical support from Dell EMC. With Windows Admin Center, administrators can tier storage, implement resiliency, provision VMs and storage, configure networking, and monitor node health and performance with Dell EMC OpenManage plug-in, all with just a few clicks.
Visit our website for more details on Dell EMC Solutions for Azure Stack HCI. If you have any questions, contact your Dell EMC exports or you can also email the Dell EMC Azure Stack HCI team directly at firstname.lastname@example.org
Authored by Sam Lucido