Data Center Storage

Cost-Effective Strategies, Implementation, and Management

Hubbert Smith

• Publisher: Auerbach Publications
• Year: 2016
• ISBN:
  9781466507814
• Edition: 1
• Topic: Business
• Subtopic: Operations
• Index: Business

We overspend on data center storage... yet, we fall short of business requirements. It's not about the technologies. It's about the proper application of technologies to deliver storage services efficiently and affordably. It's about meeting business requirements dependent on data center storage. Spend less, deliver more. Data Center Storage: Cost-Effective Strategies, Implementation, and Management provides an industry insider's insight on how to properly scope, plan, evaluate, and implement storage technologies to maximize performance, capacity, reliability, and power savings. It provides business and use-case focused coverage of storage technology, including storage area networks (SAN), capacity-optimized drives, and solid-state drives. It offers key insights on financially responsible spending for data center storage. Delivered in accessible language, the book starts with a discussion of the business merits of replacing direct attached, compartmentalized storage with consolidated SAN-attached storage. The author advises on the use of service level applications (SLAs) as a tool to drive business unit collaboration with IT and prioritize those actions that impact productivity and profit from those that are less critical. This business guide to applied technologies disassembles big problems into digestible segments to help you understand, quantify, and fix any problems that arise as you work towards meeting your growing storage needs. The book builds on the consolidation and SLA driven approach to take advantage of the compelling benefits and potential savings of managed hosting and cloud storage.

Part I
Building Blocks, Power, and Consolidation

In Part I, we consolidate server direct attach storage, improve on single tier storage, and discuss unrelenting demand growth for performance capacity and the expenses related to hardware price (CapX), power (OpX), management (OpX), data aging (OpX), and data center outgrowth (CapX). We demystify both the technology and the business aspects of storage performance, replication, backup/recovery/archival, and storage virtualization.

Part I establishes a baseline for single-tier storage using critical ratios for performance, capacity, cost, and power as well as data aging (these same ratios will be compared for multitier and cloud storage architectures).

Chapter 1

The Disk Drive: The Fundamental Building Block of Enterprise Storage

All enterprise storage is based on the basic building block: the hard disk drive or HDD.

We will start with key metrics of the hard disk drive: price, performance, power, and capacity. We’re going to identify the important stuff and remove the noise. Once we have a command of foundation and key metrics, the systems, processes, and economic delivery on service levels readily falls into place.

HDDs come in various price/performance/power/capacities and we can remove the complexity to arrive at the right tool for the job at hand. In the real world, enterprise storage is not about which system offers the cheapest gigabytes for the money. Enterprise storage is not about which system has the highest performance benchmark number. In the real world, enterprise storage is about the balance of adequate performance, adequate capacity, adequate reliability, and data protection, all at the best possible price. And this book is about disassembling the problem into manageable but related components to find that balance for the situation at hand.

Most people, including IT people, consider storage performance as the realm of PhDs: complex and difficult to understand. I am here to tell you, it is much simpler than it may appear. We can overcome the perceived complexity of storage performance by deconstructing this messy, complex problem into easy-to-understand components, focusing on the important, pertinent facts, and eliminating the nonrelevant noise.

Our objective is to remove the mystery, remove the mush, remove the fear, uncertainty, and doubt (FUD), and explore the mystery of storage performance and storage reliability. Everywhere possible, we will focus on the quantifiable and push aside the immaterial. HDDs are the fundamental building blocks of enterprise storage, so that’s where we will start. We will continue on to a systems view; we’ll address operational improvements; and then we’ll review new system architectures with variations (dynamic storage tiering, hybrid cloud, and private cloud, to drop a few names).

1.1 Using a Metrics-Based Approach to Get Past the Complexity

Ever run into one of those personalities who, when you ask the time of day, tells you how to build a clock? We’re just looking for the time of day—we don’t want or need to know how to build a clock. This metaphor applies well to data center storage. Storage vendors and suppliers have been known to claim leadership based on one (and usually only one) dimension of their product.

My favorite example is when a newbie enterprise solid state product marketing person claimed a high performance number (something like 100,000 IOPS, or input-output operations per second) and then crowed that to achieve that same number of IOPS would require some hundreds of 15K rpm drives. While we can relate to the notion that a vendor needs marketing sound bites—such as the world’s best storage performance benchmark—we also know performance benchmarks alone are not the whole story. We know IOPS can be large or small; the workload can be random or sequential; the workload can be some mix of reads or writes. The one-dimensional “market-ecture” above, though factually correct, does not remotely resemble anything in the real world. The benchmark above assumed the smallest possible block size (512 bytes), 100 percent random workload, and 100 percent read 0 percent write workload—a situation never encountered in mainstream data storage.

■ In the real world, block sizes vary, but the typical block size is 4,000 bytes (not 512 bytes).

■ In the real world, the workload is sometimes random and sometimes sequential (not 100 percent random).

■ In the real world, there is a mix of reads and writes; the rule of thumb is a 70:30 read:write ratio (not read-only).

■ And obviously, the workload (mix of block sizes, read versus write, and random versus sequential) can vary based on the storage task/application, as well as on the time of day, week, month, quarter, or even year.

Our approach is to focus on real-world benchmarks, real-world use cases, and key components. We make a conscious effort to cull the noise, the irrelevant, and the imponderable from the equation.

We’ll discover how to establish your own relevant criteria, applicable to your shop, rather than buying into those one-dimensional talking points. To be fair, to counterbalance the self-serving people; the data center storage industry has no shortage of good folks whose first instinct is to make things right with the customer. The techniques and approaches we’ll cover will help you clearly identify those good folks in the industry, in contrast to the other kind.

1.2 Metrics for the Basic Building Block: Hard Disk Drives and Solid State Devices

For HDD building blocks, our approach is to structure a decision-making process around key metrics: price, performance, power, and capacity. As our objective is to turn raw data into useful information; we can take these four key variables (raw data) and evaluate them using key ratios (useful information), as shown in Table 1.1.

Table 1.1 Hard Disk Drive Key Ratios (Bigger is Better)

Notice the benefit (performance or capacity) is always in the top of the fraction (numerator), and the expense (cost or power) is always in the bottom of the fraction (denominator).

This way, bigger is always better.

The key ratios chart in Table 1.2 serves to simplify the total storage view. It tells us 10K drives are better in GB/$, better in GB/watt, and better in IOPS/$; but not better in IOPS/watt than 15K rpm drives. It also serves as the underlying data for Figure 1.1, Figure 1.2, Figure 1.3, Figure 1.4, Figure 1.5, Figure 1.6 and Figure 1.7.

Table 1.2 Hard Disk Drive Key Ratios Raw Data

Sources: Vendor HDD data sheets, Nextag.com for approximate price, storager-eview.com for approximate Web server performance.

Storage system engineering is sometimes (but not always) about performance, and it’s also important to see the entire picture including price, power, and capacity (Figure 1.1).

Figure 1.1 Key Metrics for 2.5” Small Form Factor 15K rpm, 146G

Clearly, the strength of this product is IOPS/watt. It’s noticeably anemic in the areas of GB/$, GB/watt, and IOPS/$.

The creators of this small form factor 2.5” HDD product were motivated by their IT customers to add more storage performance in over-full data centers with limited power, limited A/C, and limited floor space (sound familiar?).

In situations where slow storage interferes with end-user productivity (and, as a result, this costs the company money), this class of performance-optimized HDD or SSD is the right tool for the job. But in situations where storage performance has a minimal impact on end-user productivity (e.g., e-mail), there are other, more financially responsible tools for t...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• About the author
• What, Exactly, Will We Accomplish?
• Part I Building Blocks, Power, and Consolidation
• Part II Managing Aging Data and E-Mail Expenses
• Part III Managed Hosting and Cloud
• Appendix A Storage Protocol Basics
• Appendix B Project Management
• Appendix C People, Process, Technology
• Appendix D Root Cause, Corrective Action Process
• Appendix E Iometer: Performance Testing in the Lab
• Glossary
• Index