changing rapidly, and administrators and architects need guidance along this journey, the journey toward a software-defined data center.
When talking to customers and partners on the subject of the software-defined data center, a couple of concerns typically arise. Two parts of the data center have always been historically challenging and/or problematic – namely, networking and storage. Networking problems and concerns (and those related to security, for that matter) have been largely addressed with VMware NSX, which allows virtualization and networking administrators to work closely together on providing a flexible yet very secure foundation for the workloads they manage. This is done by adding an abstraction layer on top of the physical environment and moving specific services closer to the workloads (for instance, firewalling and routing), where they belong.
Over 30 years ago, RAID was invented, which allowed you to create logical devices formed out of multiple hard disk drives. This allowed for more capacity, higher availability, and of course, depending on the type of RAID used, better performance. It is fair to say, however, that the RAID construct was created as a result of the many constraints at the time. Over time, all of these constraints have been lifted, and the hardware evolution started the (software-defined) storage revolution. SSDs, PCIe-based flash, NVMe, 10GbE, 25GbE (and higher), RDMA, 12 Gbps SAS, and many other technologies allowed storage vendors to innovate again and to make life simpler. No longer do we need to wide-stripe across many disks to meet performance expectations, as that single SSD device can now easily serve 50,000 IOPS. And although some of the abstraction layers, such as traditional RAID or disk groups, may have been removed, most storage systems today are not what I would consider admin/user friendly.
There are different protocols (iSCSI, FCoE, NFS, FC), different storage systems (spindles, hybrid, all flash), and many different data services and capabilities these systems provide. As a result, we cannot simply place an abstraction layer on top as we have done for networking with NSX. We still need to abstract the resources in some shape or form and most definitely present them in a different, simpler manner. Preferably, we leverage a common framework across the different types of solutions, whether that is a hyper-converged software solution like Virtual SAN or a more traditional iSCSI-based storage system with a combination of flash and spindles.
Storage policy–based management is this framework. If there is anything you need to take away from this book, then it is where your journey to software-defined storage should start, and that is the SPBM framework that comes as part of vSphere. SPBM is that abstraction layer that allows you to consume storage resources across many different types of storage (with different protocols) in a simple and uniform way by allowing you to create policies that are passed down to the respective storage system through the VMware APIs for Storage Awareness.
In order to be able to create an infrastructure that caters to the needs of your customers (application owners/users), it is essential that you, the administrator or architect, have a good understanding of all the capabilities of the different storage platforms, the requirements of the application, and how architectural decisions can impact availability, recoverability, and performance of your workloads.
But before you even get there, this book will provide you with a good foundational understanding of storage concepts including thin LUNs, protocols, RAID, and much more. This will be quickly followed by the software-defined storage options available in a VMware-based infrastructure, with a big focus on Virtual Volumes and Virtual SAN.
Many have written on the subject of software-defined storage, but not many are as qualified as Martin. Martin is one of the few folks who have managed to accrue two VCDX certifications, and as a global cloud architect has a wealth of experience in this field. He is going to take you on a journey through the world of software-defined storage in a VMware-based infrastructure and teach you the art of architecture along the way.
I hope you will enjoy reading this book as much as I have.
Duncan Epping
Chief Technologist, Storage and Availability, VMware
Introduction
Storage is typically the most important element of any virtual data center. It is the key component in system performance, availability, scalability, and manageability. It has also traditionally been the most expensive component from a capital and operational cost perspective.
The storage infrastructure must meet not only today's requirements, but also the business needs for years to come, because of the capital expenditure costs historically associated with the hardware. Storage and vSphere architects must therefore make the most informed choices possible, designing solutions that take into account multiple complex and contradictory business requirements, technical goals, forecasted data growth, constraints, and of course, budget.
In order for you to be confident about undertaking a vSphere storage design that can meet the needs of a whole range of business and organization types, you must understand the capabilities of the platform. Designing a solution that can meet the requirements and constraints set out by the customer requires calling on your experience and knowledge, as well as keeping up with advances in the IT industry. A successful design entails collecting information, correlating it into a solid design approach, and understanding the design trade-offs and design decisions.
The primary content of this book addresses various aspects of the VMware vSphere software-defined storage model, which includes separate components. Before you continue reading, you should ensure that you are already well acquainted with the core vSphere products, such as VMware vCenter Server and ESXi, the type 1 hypervisor on which the infrastructure's virtual machines and guest operating systems reside.
It is also assumed that you have a good understanding of shared storage technologies and networking, along with the wider infrastructure required to support the virtual environment, such as physical switches, firewalls, server hardware, array hardware, and the protocols associated with this type of equipment, which include, but are not limited to, Fibre Channel, iSCSI, NFS, Ethernet, and FCoE.
Who Should Read This Book?
This book will be most useful to infrastructure architects and consultants involved in designing new vSphere environments, and administrators charged with maintaining existing vSphere deployments who want to further optimize their infrastructure or gain additional knowledge about storage design. In addition, this book will be helpful for anyone with a VCA, VCP, or a good foundational knowledge who wants an in-depth understanding of the design process for new vSphere storage architectures. Prospective VCAP, VCIX, or VCDX candidates who already have a range of vSphere expertise but are searching for that extra bit of detailed knowledge will also benefit.
What Is Covered in This Book?
VMware-based storage infrastructure has changed a lot in recent years, with new technologies and new storage vendors stepping all over the established industry giants, such as EMC, IBM, and NetApp. However, life-cycle management of the storage platform remains an ongoing challenge for enterprise IT organizations and service providers, with hardware renewals occurring on an ongoing basis for many of VMware's global customer base.
This book aims to help vSphere architects, storage architects, and administrators alike understand and design for this new generation of VMware-focused software-defined storage, and to drive efficiency through simple, less complex technologies that do not require large numbers of highly trained storage administrators to maintain.
In addition, this book aims to help you understand the design factors associated with these new vSphere storage options. You will see how VMware is addressing these data-center challenges through its software-defined storage offerings, Virtual SAN and Virtual Volumes, as well as developing cloud automation approaches to these next-generation storage solutions to further simplify operations.
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