Home > Articles

Virtualizing SQL Server with VMware: Architecting for Performance: Storage

This chapter from Virtualizing SQL Server with VMware: Doing IT Right first covers the key aspects of storage architecture relevant to both physical and virtual environments as well as the differences you need to understand when architecting storage, specifically for virtualized SQL Server Databases.
This chapter is from the book

All aspects of architecting your SQL Server Database for performance are important. Storage is more important than most when compared to the other members of the IT Food Group family we introduced in Chapter 5, “Architecting for Performance: Design,” which consists of Disk, CPU, Memory, and Network. Our experience has shown us, and data from VMware Support validates this belief, that more than 80% of performance problems in database environments, and especially virtualized environments, are directly related to storage. Understanding the storage architecture in a virtualized environment and getting your storage architecture right will have a major impact on your database performance and the success of your SQL Server virtualization project. Bear in mind as you work through your storage architecture and this chapter that virtualization is bound by the laws of physics—it won’t fix bad code or bad database queries. However, if you have bad code and bad queries, we will make them run as fast as possible.

This chapter first covers the key aspects of storage architecture relevant to both physical and virtual environments as well as the differences you need to understand when architecting storage, specifically for virtualized SQL Server Databases. Many of the concepts we discuss will be valid for past versions of SQL Server and even the newest release, SQL Server 2014.

We provide guidance on what our experience has taught us are important database storage design principles. We present a top-down approach covering SQL Server Database and Guest OS Design, Virtual Machine Template Design, followed by VMware vSphere Hypervisor Storage Design and then down to the physical storage layers, including using server-side flash acceleration technology to increase performance and provide greater return on investment. We conclude the chapter by covering one of the biggest IT trends and its impact on SQL Server. Throughout this chapter, we give you architecture examples based on real-world projects that you can adapt for your purposes.

When designing your storage architecture for SQL Server, you need to clearly understand the requirements and have quantitative rather than subjective metrics. Our experience has taught us to make decisions based on fact and not gut feeling. You will need to benchmark and baseline your storage performance to clearly understand what is achievable from your design. Benchmarking and baselining performance are critical to your success, so we’ve dedicated an entire chapter (Chapter 10, “How to Baseline Your Physical SQL Server System”) to those topics. In this chapter, we discuss some of the important storage system component performance aspects that will feed into your benchmarking and baselining activities.

The Five Key Principles of Database Storage Design

When architecting storage for SQL Server, it’s important to understand a few important principles. These will help guide your design decisions and help you achieve acceptable performance both now and in the future. These principles are important because over the past decade, CPU performance has increased at a much faster pace than storage performance, even while capacity has exploded.

Principle 1: Your database is just an extension of your storage

The first principle is highlighted in Figure 6.1: that your database is just an extension of your storage. A database is designed to efficiently and quickly organize, retrieve, and process large quantities of data to and from storage. So increasing the parallelism of access to storage resources at low latency will be an important goal. Later in this chapter, we cover how to optimize the architecture of your database to maximize its storage performance and parallelism. When you understand this principle, it’s easy to understand why getting your storage design and performance is so critical to the success of your SQL Server Database virtualization project.

Figure 6.1

Figure 6.1 Quote from Michael Webster, VMworld 2012

Principle 2: Performance is more than underlying storage devices

The next key principle is that storage performance is more than just about underlying storage devices and spindles, although they are very important too. SQL Server storage performance is multidimensional and is tightly coupled with a number of different system components, such as the number of data files allocated to the database, the number of allocated vCPUs, and the amount of memory allocated to the database. This is why we like to use the term “IT Food Groups,” because it is so important to feed your database the right balance of these critical resources. This interplay between resources such as CPU, Memory, and Network and their impact on storage architecture and performance will be covered in subsequent sections of this chapter.

Principle 3: Size for performance before capacity

Figure 6.2 is loosely based on the eighteenth-century quote “The bitterness of poor quality remains long after the sweetness of low price is forgotten,” by Benjamin Franklin. Both quotes are extremely relevant to SQL Server database and storage performance.

Figure 6.2

Figure 6.2 Quote from Michael Webster, VMworld 2013

This brings us to the next key principle. In order to prevent poor performance from being a factor in your SQL Server virtualization project (refer to Figure 6.2), you should design storage for performance first (IOPS and latency), then capacity will take care of itself. Capacity is the easy part. We will show you later in this chapter how compromising on certain storage configurations on the surface can actually cost you a lot more by causing unusable capacity due to poor performance.

Principle 4: Virtualize, but without compromise

The next principle is that virtualizing business-critical SQL Server databases is all about reducing risk and not compromising on SLAs. Virtualize, but without compromise. There is no need to compromise on predictability of performance, quality of service, availability, manageability, or response times. Your storage architecture plays a big part in ensuring your SQL databases will perform as expected. As we said earlier, your database is just an extension of your storage. We will show you how to optimize your storage design for manageability without compromising its performance.

Believe it or not, as big of advocates as we are about virtualizing SQL Server, we have told customers in meetings that now is not the right time for this database to be virtualized. This has nothing to do with the capability of vSphere or virtualization, but more to do with the ability of the organization to properly operate critical SQL systems and virtualize them successfully, or because they are not able or willing to invest appropriately to make the project a success. If you aren’t willing to take a methodical and careful approach to virtualization projects for business-critical applications, in a way that increases the chances of success, then it’s not worth doing. Understand, document, and ensure requirements can be met through good design and followed by testing and validation. It is worth doing, and it is worth “Doing It Right!”

Principle 5: Keep it standardized and simple (KISS)

This brings us to the final principle. Having a standardized and simplified design will allow your environment and databases to be more manageable as the numbers scale while maintaining acceptable performance (see Principle 4). If you have a small number of standardized templates that fit the majority of your database requirements and follow a building-block approach, this is very easy to scale and easy for your database administrators to manage. We’ll use the KISS principle (Keep It Standardized and Simple) throughout this chapter, even as we dive into the details. Once you’ve made a design decision, you should standardize on that decision across all your VM templates. Then when you build from those templates, you’ll know that the settings will always be applied.

InformIT Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from InformIT and its family of brands. I can unsubscribe at any time.


Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.


Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.


If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@informit.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.


Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.


This site is not directed to children under the age of 13.


Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.


Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.informit.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.


This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020