Expanding VxRail Dynamic Node Storage Options with PowerFlex
Wed, 09 Feb 2022 19:53:55 -0000|
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It was recently announced that Dell VxRail dynamic nodes now supports Dell PowerFlex. This announcement expands the storage possibilities for VxRail dynamic nodes, providing a powerful and complimentary option for hyperconverged data centers. A white paper published by the Dell Technologies Solutions Engineering team details this configuration with VxRail dynamic nodes and PowerFlex.
In this blog we will explore how to use VxRail dynamic nodes with PowerFlex and explain why the two in combination are beneficial for organizations. We will begin by providing an overview for the dynamic nodes and PowerFlex, then describe why this duo is beneficial, and finally we will look at some of the exciting aspects of the white paper.
VxRail dynamic nodes and PowerFlex
VxRail dynamic nodes are compute-only nodes, meaning these nodes don’t provide vSAN storage. They are available in the E, P, and V Series and accommodate a large variety of use cases. VxRail dynamic nodes rely on an external storage resource as their primary storage, which in this case is PowerFlex.
The following diagram shows a traditional VxRail environment is on the left. This environment uses VMware vSAN datastore for storage. The right side of the diagram is a VxRail dynamic node cluster. The VxRail dynamic nodes are compute only nodes, and, in this case rely on PowerFlex for storage. In this diagram the VxRail cluster, the VxRail dynamic node cluster, and the PowerFlex storage can all be scaled independently of one another for certain workloads. For example, some may want to adjust resources for Oracle environments to reduce license costs.
To learn more about VxRail dynamic nodes, see my colleague Daniel Chiu’s blog on the VxRail 7.0.240 release.
PowerFlex is a software defined infrastructure that delivers linear scaling of performance and resources. PowerFlex is built on top of PowerEdge servers and aggregates the storage of four or more PowerFlex nodes to create a high-performance software defined storage system. PowerFlex uses a traditional TCP/IP network to connect nodes and deliver storage to environments. This is the only storage platform for VxRail dynamic nodes that uses an IP network. Both of these attributes are analogous to how VxRail delivers storage.
If it seems confusing because VxRail and PowerFlex seem to share many of the same characteristics, it is they do share many of the same characteristics. However, this is why it also makes sense to bring them together. This section of this blog describes how the two can be combined to deliver a powerful architecture for certain applications.
The following diagram shows the logical configuration of PowerFlex and VxRail combined. Starting at the top of the diagram, you will see the VxRail cluster, consisting of four dynamic nodes. These dynamic nodes are running the PowerFlex Storage Data Client (SDC), a software-based storage adapter, which runs in the ESXi kernel. The SDC enables the VxRail dynamic nodes to consume volumes provisioned from the storage on the PowerFlex nodes.
In the lower half of the diagram, we see the PowerFlex nodes and the storage they present. The cluster contains four PowerFlex storage-only nodes. In these nodes, the internal drives are aggregated into a storage pool that spans across all four nodes. The storage pool capacity can then be provisioned as PowerFlex volumes to the VxRail dynamic nodes.
AI workloads offer a great example of where it makes perfect sense to bring these two technologies together. There has been a lot of buzz around virtualizing AI, ML, and HPC workloads. Dell, NVIDIA, and VMware have done amazing things in this area, including NVIDIA AI Enterprise on VxRail. Now you may think this does not matter to your organization, as there are no uses for AI, ML, or HPC in your organizations, but uses for AI are constantly evolving. For example, AI is even being used extensively in agriculture.
These new AI technologies are data driven and require massive amounts of data to train and validate models. This data needs to be stored somewhere, and the systems processing benefit from quick access to it and VxRail is awesome for that. There are exceptions, what if your data set is too large for VxRail, or what if you have multiple AI models that need to be shared amongst multiple clusters?
The typical response in this scenario is to get a storage array for the environment. That would work, except you’ve just added complexity to the environment. Many users move to HCI to drive complexity out of their environment. Fibre channel is a great example of this complexity.
To reduce complexity, there’s another option, just use PowerFlex. PowerFlex can support hundreds of nodes, enabling highly-performant storage needed for modern, data hungry applications. Additionally, it operates on standard TCP/IP networks, eliminating the need for a dedicated storage switch fabric. This makes it an ideal choice for virtualized AI workloads.
The idea of a standard network may be important to some organizations, due to the complexity aspects or they may not have the in-house talent to administer a Fibre channel. This is particularly true in areas where administrators are hard to find. Leveraging the skills and resources already available within an organization, now more than ever, is extremely important.
Another area where PowerFlex backed VxRail dynamic nodes can be beneficial is with data services like data at rest encryption (D@RE). Both vSAN and PowerFlex support D@RE technology. When encryption is run on a host, the encryption/decryption process consumes resources. This impact can vary depending on the workload. If the workload has a lot of I/O, the resource utilization (CPU and RAM) could be more than a workload with lower I/O. When D@RE is offloaded, those resources needed for D@RE can be used for other tasks, such as workloads.
Beyond D@RE, PowerFlex has many other built in data resiliency and protection mechanisms. These include a distributed mesh mirroring system and native asynchronous replication. These functions help deliver fast data access and a consistent data protection strategy.
The impact of storage processing, like encryption, can impact the number of hosts that need to be licensed. Good examples of this are large databases with mllions of transactions per minute (TPM). For each data write there is an encryption process. This process can be small and appear inconsequential, that is until you have millions of those processes happening in the same time span. This can cause a performance degradation if there aren’t enough resources to handle both the encryption processing and the CPU/RAM demands of the database environment and can lead to needing additional hosts to support the database environment.
In such a scenario, it can be advantageous to use VxRail dynamic nodes with PowerFlex. This offloads the encryption to PowerFlex allowing all the compute performance to be delivered to the VMs.
Dell PowerFlex with VxRail Dynamic Nodes – White Paper
The Solutions Engineering team has included many graphics detailing both the logical and physical design of how VxRail dynamic nodes can be configured with PowerFlex.
It highlights several important prerequisites, including that you will need to be using VxRail system software version 7.0.300 or above. This is important as this release is when support for PowerFlex was added to VxRail dynamic nodes. If the VxRail environment is not at the correct version, it could cause delays while the environment is upgraded to a compatible version.
Beyond just building an environment, the white paper also details administrating the environment. While administration is a relatively straight forward for seasoned administrators, it’s always good to have instructions in case an administrator is sick or other members of the team are gaining experience.
All of this and so much more are outlined in the white paper. If you are interested in all the details, be sure to read through it. This applies if your team is currently using VxRail and looking to add dynamic nodes or if you have both PowerFlex and VxRail in your environment and you want to expand the capabilities of each.
This blog provided an overview of VxRail dynamic nodes and how they can take advantage of PowerFlex software defined storage when needed. This includes reducing licensing costs and keeping complexity, like fiber channel, to a minimum in your environment. To find out more, read the white paper or talk with your Dell representative.
Author: Tony Foster
Related Blog Posts
New File Services Capabilities of PowerFlex 4.0
Tue, 16 Aug 2022 14:56:28 -0000|
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“Just file it,” they say, and your obvious question is “where?” One of the new features introduced in PowerFlex 4.0 is file services. Which means that you can file it in PowerFlex. In this blog we’ll dig into the new file service capabilities offered with 4.0 and how they can benefit your organization.
I know that when I think of file services, I think back to the late 90s and early 2000s when most organizations had a Microsoft Windows NT box or two in the rack that provided a centralized location on the network for file storage. Often it was known as “cheap and deep storage,” because you bought the biggest cheapest drives you could to install in that server with RAID 5 protection. After all, most of the time it was user files that were being worked on and folks already had a copy saved to their desktop. The file share didn’t have to be fast or responsive, and the biggest concern of the day was using up all the space on those massive 146 GB drives!
That was then … today file services do so much more. They need to be responsive, reliable, and agile to handle not only the traditional shared files, but also the other things that are now stored on file shares.
The most common thing people think about is user data from VDI instances. All the files that make up a user’s desktop, from the background image to the documents, to the customization of folders, all these things and more are traditionally stored in a file share when using instant clones.
PowerFlex can also handle powerful, high performance workload scenarios such as image classification and training. This is because of the storage backend. It is possible to rapidly serve files to training nodes and other high performance processing systems. The storage calls can go to the first available storage node, reducing file recall times. This of course extends to other high speed file workloads as well.
Beyond rapid recall times, PowerFlex provides massive performance, with 6-nines of availability1, and native multi-pathing. This is a big deal for modern file workloads. With VDI alone you need all of these things. If your file storage system can’t deliver them, you could be looking at poor user experience or worse: users who can’t work. I know, that’s a scary thought and PowerFlex can help significantly lessen those fears.
In addition to the performance, you can manage the file servers in the same PowerFlex UI as the rest of your PowerFlex environment. This means there is no need to learn a new UI, or bounce all over to set up a CIFS share—it’s all at your fingertips. In the UI it’s as simple as changing the tab to go from block to file on many screens.
The PowerFlex file controllers (physical) host the software for the NAS servers (logical). You start with two file controllers and can grow to 16 file controllers. Having various sizes of file controllers allows you to customize performance to meet your environment’s needs. The NAS Servers are containerized logical segmentations that provide the file services to the clients, and you can have up to 512 in a cluster. They are responsible for namespaces, security policies, and serving file systems to the clients.
Each of the file volumes that are provided by the file services are backed by PowerFlex volumes. This means that you can increase file service performance and capacity by adding PowerFlex nodes to the storage layer just like a traditional block storage instance. This allows you to independently scale performance and capacity, based on your needs.
The following table provides some of the other specs you might be wondering about.
Max file size
# of files
# of ACLs
User File Systems
Snaps per File System
Beyond the architectural goodness, file storage is something that can be added later to a PowerFlex environment. Thus, you aren’t forced to get something now because you “might” need it later. You can implement it when that project starts or when you’re ready to migrate off that single use file server. You can also grow it as you need, by starting small and growing to a large deployment with hundreds of namespaces and thousands of file systems.
With PowerFlex when someone says “file it,” you’ll know you have the capacity to support that file and many more. PowerFlex file services provide the capability to deliver the power needed for even the most demanding file-based workloads like VDI and AI/ML data classification systems. It’s as easy managing the environment as it is integrated into the UI.
If you are interested in finding out more about PowerFlex file services, contact your Dell representative.
Author: Tony Foster
1 Workload performance claims based on internal Dell testing. (Source: IDC Business Value Snapshot for PowerFlex – 2020.)
Introducing NVMe over TCP (NVMe/TCP) in PowerFlex 4.0
Fri, 26 Aug 2022 18:59:38 -0000|
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Anyone who has used or managed PowerFlex knows that an environment is built from three lightweight software components: the MDM, the SDS, and the SDC. To deploy a PowerFlex environment, the typical steps are:
- Deploy an MDM management cluster
- Create a cluster of storage servers by installing and configuring the SDS software component
- Add Protection Domains and Storage Pools
- Install the SDC onto client systems
- Provision volumes and away you go!!*
*No requirement for multipath software, this is all handled by the SDC/SDS
There have been additions to this over the years, such as an SDR component for replication and the configuration of NVDIMM devices to create finegranularity storage pools that provide compression. Also added are PowerFlex rack and appliance environments. This is all automated with PowerFlex Manager. Fundamentally, the process involves the basic steps outlined above.
So, the question is why would we want to change anything from an elegant solution that is so simple?
This is due to where the SDC component ‘lives’ in the operating system or hypervisor hosting the application layer. Referring to the diagram below, it shows that the SDC must be installed in the kernel of the operating system or hypervisor, meaning that the SDC and the kernel must be compatible. Also the SDC component must be installed and maintained, it does not just ‘exist’.
In most cases, this is fine and there are no issues whatsoever. The PowerFlex development team keeps the SDC current with all the major operating system versions and customers are happy to update the SDC within their environment when new versions become available.
There are, however, certain cases where manual deployment and management of the SDC causes significant overhead. There are also some edge use cases where there is no SDC available for specific operating systems. This is why the PowerFlex team has investigated alternatives.
In recent years, the use of Non-Volatile Memory Express (NVMe) has become pervasive within the storage industry. It is seen as the natural replacement to SCSI, due to its simplified command structure and its ability to provide multiple queues to devices, aligning perfectly with modern multi-core processors to provide very high performance.
NVMe appeared initially as a connection directly to disks within a server over a PCIe connection, progressing to being used over a variety of fabric interconnects.
Added to this is the widespread support for NVMe/TCP across numerous operating system and hypervisor vendors. Most include support natively in their kernels.
There have been several announcements by Dell Technologies over the past months highlighting NVMe/TCP as an alternative interconnect to iSCSI across several of the storage platforms within the portfolio. It is therefore a natural progression for PowerFlex to also provide support for NVMe/TCP, particularly because it already uses a TCP-based interconnect.
PowerFlex implements support for NVMe/TCP with the introduction of a new component installed in the storage layer called the SDT.
The SDT is installed at the storage layer. The NVMe initiator in the operating system or hypervisor communicates with the SDT, which then communicates with the SDS. The NVMe initiator is part of the kernel of the operating system or hypervisor.
Of course, because PowerFlex is so ‘flexible,’ both connection methods (SDC and NVMe/TCP) are supported at the same time. The only limitation is that a volume can only be presented using one protocol or the other.
For the initial PowerFlex 4.0 release, the VMware ESXi hypervisor is supported. This support starts with ESXi 7.0 U3f. Support for Linux TCP initiators is currently in “tech preview” as the initiators continue to grow and mature, allowing for all failure cases to be accounted for.
NVMe/TCP is a very powerful solution for the workloads that take advantage of it. If you are interested in discovering more about how PowerFlex can enhance your datacenter, reach out to your Dell representative.
Kevin M Jones, PowerFlex Engineering Technologist.
Tony Foster, Senior Principal Technical Marketing Engineer.