PowerFlex: The advantages of disaggregated infrastructure deployments
Mon, 29 Jun 2020 18:57:26 -0000
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For several years, there has been a big push from quite a number of IT vendors towards delivering solutions based on Hyperconverged Infrastructure or HCI. The general concept of HCI is to take the three primary components of IT, compute, network and storage, and deliver them in a software defined format within a building block, normally an x86 based server. These building blocks are then joined together to create a larger, more resilient environment. The software defined components are typically a hypervisor to provide compute, virtual adapters and switches for networking, along with some software that takes the local disks attached to the server, combines them with the disks directly attached to the other building blocks and presents them as a virtual storage system back to the environment.
The HCI approach is attractive to customers for a variety of reasons:
- Easy upgrades by just adding in another building block
- A single management interface for virtual compute, virtual networking and virtual storage
- Having one team to manage everything as it is all in one place
There are of course scenarios where the HCI model does not fit, the limitations are frequently associated with the software defined storage part of the environment, situations such as the following:
- Extra storage is required but additional compute and the associated licensing is not.
- Paying for database licensing on cores that are being used for virtual storage processes.
- Unused storage capacity within the HCI environment that is inaccessible to servers outside the HCI environment.
- A server requirement for a specific workload that does not match the building blocks deployed.
- When maintenance is required it impacts both compute and storage.
Several HCI vendors have attempted to address these points but often their solutions to the issues involve a compromise.
What if there was a solution that provided software defined storage that was flexible enough to meet these requirements without compromise?
Step forward PowerFlex, a product flexible enough to be deployed as an HCI architecture, a disaggregated architecture (separate compute and storage layers managed within the same fabric), or a mixture of the two.
So how can PowerFlex be this flexible?
It is all about how the product was initially designed and developed, it consists predominantly of three separate software components:
- Storage Data Client (SDC): The software component installed on the operating system that will consume storage. It can be thought of as analogous to a Fibre Channel adapter driver from the days of SAN interconnect storage arrays. It can be installed on a wide selection of operating systems and hypervisors, most Linux distributions, VMware and Windows are supported.
- Storage Data Server (SDS): The component that is installed on the server or virtual server providing local disk capacity, it works with other servers installed with the SDS software to provide a pool of storage from which volumes are allocated. It is generally installed on a Linux platform.
- Metadata Manager (MDM): The software management component, it ensures that SDC and the SDS components are behaving themselves and playing nicely together (parents of more than one child will understand).
Each of these components can be installed across a cluster of servers in a variety of ways in order to create flexible deployment scenarios. The SDC and SDS components communicate with one another over a standard TCP/IP network to form an intelligent fabric, this is all overseen by the MDM, which is not in the data path.
Some pictures will help illustrate this far better than I can with words.
By installing the SDC (the C in a yellow box) and the SDS (the S in a green box) on to the same server, an HCI environment is created.
If the SDC and SDS are installed on dedicated servers, a disaggregated infrastructure is created
And because PowerFlex is entirely flexible (the clue is in the name), HCI and disaggregated architectures can be mixed within the same environment.
What are the advantages of deploying a disaggregated environment?
- MAXIMUM FLEXIBILITY - Compute and storage resources can be scaled independently.
- CLOUD-LIKE ECONOMICS – following on from above – what if an application needs to cope with a sudden doubling of compute resource (for example, to cope with a one-off business event)? With a disaggregated deployment, the extra compute-only resources can be added temporarily into the environment, ride the peak demand, then retire afterwards, reducing expenditure by only using what is needed.
- MAXIMISE STORAGE UTILISATION - Completely heterogeneous environments can share the same storage pool.
- CHOOSE THE CORRECT CPU FOR THE WORKLOAD - Servers with frequency optimised processors can be deployed for database use and not require licenses for cores potentially performing processing related to storage.
- AVOID CREATING MULTIPLE ISLANDS OF SOFTWARE DEFINED STORAGE - A mixture of hypervisors and operating systems can be deployed within the same environment; VMware, Hyper-V and Red Hat Virtualisation, along with operating systems running on bare metal hardware, all accessing the same storage.
- UPDATE STORAGE & COMPUTE INDEPENDENTLY - Maintenance can be performed on storage nodes completely independently of compute nodes and vice versa, thereby simplifying planned downtime. This can dramatically simplify operations, especially on larger clusters and prevents storage and compute operators from accidentally treading on each other’s toes!
Whilst HCI deployments are ideal for environments where compute requirements and storage capacity increases remain in lockstep, there are many use cases where compute and storage needs grow independently, PowerFlex is capable of serving both requirements.
PowerFlex was built to allow this disaggregation of resources from day one, which means that there is no downside to performance or capacity when storage nodes are added to existing clusters, in fact there are only positives, with increased performance, capacity and resilience, setting PowerFlex apart from many other software defined storage products.
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How PowerFlex Transforms Big Data with VMware Tanzu Greenplum
Wed, 13 Apr 2022 13:16:23 -0000
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Quick! The word has just come down. There is a new initiative that requires a massively parallel processing (MPP) database, and you are in charge of implementing it. What are you going to do? Luckily, you know the answer. You also just discovered that the Dell PowerFlex Solutions team has you covered with a solutions guide for VMware Tanzu Greenplum.
What is in the solutions guide and how will it help with an MPP database? This blog provides the answer. We look at what Greenplum is and how to leverage Dell PowerFlex for both the storage and compute resources in Greenplum.
Infrastructure flexibility: PowerFlex
If you have read my other blogs or are familiar with PowerFlex, you know it has powerful transmorphic properties. For example, PowerFlex nodes sometimes function as both storage and compute, like hyperconverged infrastructure (HCI). At other times, PowerFlex functions as a storage-only (SO) node or a compute-only (CO) node. Even more interesting, these node types can be mixed and matched in the same environment to meet the needs of the organization and the workloads that they run.
This transmorphic property of PowerFlex is helpful in a Greenplum deployment, especially with the configuration described in the solutions guide. Because the deployment is built on open-source PostgreSQL, it is optimized for the needs of an MPP database, like Greenplum. PowerFlex can deliver the compute performance necessary to support massive data IO with its CO nodes. The PowerFlex infrastructure can also support workloads running on CO nodes or nodes that combine compute and storage (hybrid nodes). By leveraging the malleable nature of PowerFlex, no additional silos are needed in the data center, and it may even help remove existing ones.
The architecture used in the solutions guide consists of 12 CO nodes and 10 SO nodes. The CO nodes have VMware ESXi installed on them, with Greenplum instances deployed on top. There are 10 segments and one director deployed for the Greenplum environment. The 12th CO node is used for redundancy.
The storage tier uses the 10 SO nodes to deliver 12 volumes backed by SSDs. This configuration creates a high speed, highly redundant storage system that is needed for Greenplum. Also, two protection domains are used to provide both primary and mirror storage for the Greenplum instances. Greenplum mirrors the volumes between those protection domains, adding an additional level of protection to the environment, as shown in the following figure:
By using this fluid and composable architecture, the components can be scaled independently of one another, allowing for storage to be increased either independently or together with compute. Administrators can use this configuration to optimize usage and deliver appropriate resources as needed without creating silos in the environment.
Testing and validation with Greenplum: we have you covered
The solutions guide not only describes how to build a Greenplum environment, it also addresses testing, which many administrators want to perform before they finish a build. The guide covers performing basic validations with FIO and gpcheckperf. In the simplest terms, these tools ensure that IO, memory, and network performance are acceptable. The FIO tests that were run for the guide showed that the HBA was fully saturated, maximizing both read and write operations. The gpcheckperf testing showed a performance of 14,283.62 MB/sec for write workloads.
Wouldn’t you feel better if a Greenplum environment was tested with a real-world dataset? That is, taking it beyond just the minimum, maximum, and average numbers? The great news is that the architecture was tested that way! Our Dell Digital team has developed an internal test suite running static benchmarked data. This test suite is used at Dell Technologies across new Greenplum environments as the gold standard for new deployments.
In this test design, all the datasets and queries are static. This scenario allows for a consistent measurement of the environment from one run to the next. It also provides a baseline of an environment that can be used over time to see how its performance has changed -- for example, if the environment sped up or slowed down following a software update.
Massive performance with real data
So how did the architecture fare? It did very well! When 182 parallel complex queries were run simultaneously to stress the system, it took just under 12 minutes for the test to run. In that time, the environment had a read bandwidth of 40 GB/s and a write bandwidth of 10 GB/s. These results are using actual production-based queries from the Dell Digital team workload. These results are close to saturating the network bandwidth for the environment, which indicates that there are no storage bottlenecks.
The design covered in this solution guide goes beyond simply verifying that the environment can handle the workload; it also shows how the configuration can maintain performance during ongoing operations.
Maintaining performance with snapshots
One of the key areas that we tested was the impact of snapshots on performance. Snapshots are a frequent operation in data centers and are used to create test copies of data as well as a source for backups. For this reason, consider the impact of snapshots on MPP databases when looking at an environment, not just how fast the database performs when it is first deployed.
In our testing, we used the native snapshot capabilities of PowerFlex to measure the impact that snapshots have on performance. Using PowerFlex snapshots provides significant flexibility in data protection and cloning operations that are commonly performed in data centers.
We found that when the first storage-consistent snapshot of the database volumes was taken, the test took 45 seconds longer to complete than initial tests. This result was because it was the first snapshot of the volumes. Follow-on snapshots during testing resulted in minimal impact to the environment. This minimal impact is significant for MPP databases in which performance is important. (Of course, performance can vary with each deployment.)
We hope that these findings help administrators who are building a Greenplum environment feel more at ease. You not only have a solution guide to refer to as you architect the environment, you can be confident that it was built on best-in-class infrastructure and validated using common testing tools and real-world queries.
The bottom line
Now that you know the assignment is coming to build an MPP database using VMware Tanzu Greenplum -- are you up to the challenge?
If you are, be sure to read the solution guide. If you need additional guidance on building your Greenplum environment on PowerFlex, be sure to reach out to your Dell representative.
Resources
Authors:
- Tony Foster – Dell Technologies, Twitter: @wonder_nerd
LinkedIn - Sue Mosovich – VMware
Looking Ahead: Dell Container Storage Modules 1.2
Mon, 21 Mar 2022 14:31:56 -0000
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The quarterly update for Dell CSI Drivers & Dell Container Storage Modules (CSM) is here! Here’s what we’re planning.
CSM Features
New CSM Operator!
Dell Container Storage Modules (CSM) add data services and features that are not in the scope of the CSI specification today. The new CSM Operator simplifies the deployment of CSMs. With an ever-growing ecosystem and added features, deploying a driver and its affiliated modules need to be carefully studied before beginning the deployment.
The new CSM Operator:
- Serves as a one-stop-shop for deploying all Dell CSI driver and Container Storage Modules
- Simplifies the install and upgrade operations
- Leverages the Operator framework to give a clear status of the deployment of the resources
- Is certified by Red Hat OpenShift
In the short/middle term, the CSM Operator will deprecate the experimental CSM Installer.
Replication support with PowerScale
For disaster recovery protection, PowerScale implements data replication between appliances by means of the the SyncIQ feature. SyncIQ replicates the data between two sites, where one is read-write while the other is read-only, similar to Dell storage backends with async or sync replication.
The role of the CSM replication module and underlying CSI driver is to provision the volume within Kubernetes clusters and prepare the export configurations, quotas, and so on.
CSM Replication for PowerScale has been designed and implemented in such a way that it won’t collide with your existing Superna Eyeglass DR utility.
A live-action demo will be posted in the coming weeks on our VP YouTube channel: https://www.youtube.com/user/itzikreich/.
CSI features
Across the portfolio
In this release, each CSI driver:
- Supports OpenShift 4.9
- Supports Kubernetes 1.23
- Supports the CSI Spec 1.5
- Updates the latest UBI-minimal image
- Supports fsGroupPolicy
fsGroupPolicy support
Kubernetes v1.19 introduced the fsGroupPolicy to give more control to the CSI driver over the permission sets in the securityContext.
There are three possible options:
- None -- which means that the fsGroup directive from the securityContext will be ignored
- File -- which means that the fsGroup directive will be applied on the volume. This is the default setting for NAS systems such as PowerScale or Unity-File.
- ReadWriteOnceWithFSType -- which means that the fsGroup directive will be applied on the volume if it has fsType defined and is ReadWriteOnce. This is the default setting for block systems such as PowerMax and PowerStore-Block.
In all cases, Dell CSI drivers let kubelet perform the change ownership operations and do not do it at the driver level.
Standalone Helm install
Drivers for PowerFlex and Unity can now be installed with the help of the install scripts we provide under the dell-csi-installer directory.
A standalone Helm chart helps to easily integrate the driver installation with the agent for Continuous Deployment like Flux or Argo CD.
Note: To ensure that you install the driver on a supported Kubernetes version, the Helm charts take advantage of the kubeVersion field. Some Kubernetes distributions use labels in kubectl version (such as v1.21.3-mirantis-1 and v1.20.7-eks-1-20-7) that require manual editing.
Volume Health Monitoring support
Drivers for PowerFlex and Unity implement Volume Health Monitoring.
This feature is currently in alpha in Kubernetes (in Q1-2022), and is disabled with a default installation.
Once enabled, the drivers will expose the standard storage metrics, such as capacity usage and inode usage through the Kubernetes /metrics endpoint. The metrics will flow natively in popular dashboards like the ones built-in OpenShift Monitoring:
Pave the way for full open source!
All Dell drivers and dependencies like gopowerstore, gobrick, and more are now on Github and will be fully open-sourced. The umbrella project is and remains https://github.com/dell/csm, from which you can open tickets and see the roadmap.
Google Anthos 1.9
The Dell partnership with Google continues, and the latest CSI drivers for PowerScale and PowerStore support Anthos v1.9.
NFSv4 POSIX and ACL support
Both CSI PowerScale and PowerStore now allow setting the default permissions for the newly created volume. To do this, you can use POSIX octal notation or ACL.
- In PowerScale, you can use plain ACL or built-in values such as private_read, private, public_read, public_read_write, public or custom ones;
- In PowerStore, you can use the custom ones such as A::OWNER@:RWX, A::GROUP@:RWX, and A::OWNER@:rxtncy.
Useful links
For more details you can:
- Watch these great CSM demos on our VP YouTube channel: https://www.youtube.com/user/itzikreich/
- Read the FAQs
- Subscribe to Github notification and be informed of the latest releases on: https://github.com/dell/csm
- Ask for help or chat with us on Slack
Author: Florian Coulombel