Seven Keys to Selecting the Right Storage Architecture for Enterprise VDI Deployments

Transcription

1 November 2010 By Jerome M Wendt DCIG, LLC 7511 Madison Street Omaha NE O Seven Keys to Selecting the Right Storage Architecture for Enterprise VDI Deployments 2010 DCIG LLC. All rights reserved.

2 Seven Keys to Selecting the Right Storage Architecture for Enterprise VDI Deployments Table of Contents Executive Summary 1 Desktop Virtualization Poised for Enterprise Ramp-up in 2010 and Beyond 2 VDI Creates High End Storage Needs 2 3 CIO of National Retailer Gets a VDI Wakeup Call 4 Beware VDI s Networked Storage Costs VDI s Conflicting Storage Demands 2 The Seven Keys to Selecting the Right Storage Architecture 3 for VDI Environments 3 Key #1 Cost-effective Scale Out of Storage Capacity 3 Key #2 Flexibility to Introduce the Right Tier of Disk 3 Key #3 Automated Data Placement 4 Key #4 Storage Controllers that Scale Out 4 Key #5 Supports NAS 5 Key #6 Integrates with Existing VMware Management Tools 5 Key #7 Efficiently Stores Data Symantec VirtualStore Satisfies These Seven Key Requirements 5 of Enterprise VDI Deployments 2010 DCIG LLC. All rights reserved. p. ii

3 Seven Keys to Selecting the Right Storage Architecture for Enterprise VDI Deployments Executive Summary The conversation around desktop virtualization at the enterprise level is changing. Once reserved primarily for use by remote users, advances in desktop virtualization technology coupled with dramatic price declines in desktop, networking and storage components have made it both practical and affordable for enterprise organizations to virtualize all of their corporate desktops. Yet early adopters of desktop virtualization are discovering that it is not the panacea that virtual desktop infrastructure (VDI) advocates claim it to be. VDI is increasingly being adopted to eliminate the problems of avail ability, reliability, scalability, security and performance challenges that come with physical desktop environments. However enterprise class storage systems required to store virtual desktop images can negate the savings that results from VDI. It is for these reasons that enterprises need to carefully weigh what type of storage architecture they choose to deploy to support their VDI deployment. This white paper will examine: The factors driving the increased enterprise interest in desktop virtualization Why desktop virtualization creates high end storage needs Why traditional storage architectures are ill equipped to meet these demands How early adopters have gotten stung by the unexpected storage challenges and costs associated with VDI deployments The seven keys to selecting the right storage architecture for enterprise VDI deployments How Symantec VirtualStore satisfies these seven key requirements 2010 DCIG LLC. All rights reserved. p. 1

4 Seven Keys to Selecting the Right Storage Architecture for Enterprise VDI Deployments Desktop Virtualization Poised for Enterprise Ramp-up in 2010 and Beyond Enterprise users love the experience that their desktops provide almost as much as enterprise IT organizations dread supporting them. Desktops provide users access to everything that they need to do their job: a dedicated system, applications specific to their needs, network connectivity and ample computing resources. However disparate hardware and operating system platforms; continual application and operating system maintenance; unsecured, distributed corporate data; and, constant security threats have turned desktop management into a corporate nightmare from both a support and risk perspective. Desktop virtualization promises to change that. Desktop virtualization technology has sufficiently matured such that even power users can get the desktop experience that they covet even as desktop virtualization hands back to enterprise IT the opportunity to centralize and secure corporate desktops. This maturation of desktop virtualization technology coupled with the availability of inexpensive hardware components at the desktop, networking and storage layers is making desktop virtualization both affordable and practical. This is leading to high levels of interest among enterprise organizations in virtualizing their desktops. A 2009 survey by Imprivata, Inc, of executives in 132 organizations found that 73% were investigating or have plans to implement a virtual desktop infrastructure (VDI) in Of those looking to adopt VDI, 78% named simplifying desktop management as their primary motivation for moving forward while 72% cited savings in equipment, electricity and maintenance as other reasons for deploying it. 1 DCIG has also attended a number of presentations in 2010 given by executives from leading desktop virtualization providers. In these sessions, they have specifically commented on how the size of planned desktop virtualization initiatives in enterprises has grown. In 2009 a conversation for a large VDI deployment consisted of virtualizing 5,000 10,000 desktops. In 2010 the numbers in those conversations with enterprises routinely discuss virtualizing tens of thousands of their corporate desktops. So while the payback associated with desktop virtualization that is driving this adoption of VDI is potentially huge, so are the risks. Among its drawbacks, two that specifically gives enterprise organizations pause are the cost and complexity of the storage infrastructure needed to support it. VDI Creates High End Storage Needs Early adopters are finding out that the demands on the storage layer increase significantly once desktops are virtualized. While the workload on the desktop layer stays the same or even decreases and the network layer experiences a moderate to heavy increase in traffic, the back-end storage layer absorbs the brunt of the VDI workload. To handle this workload, enterprise-class storage systems that provide availability, data protection, performance, reliability and scalability are now needed. Often times, the cost savings associated with removing the dependence on internal hard drives are negated by the cost of enterprise storage arrays to support VDI. It is these increased costs associated with using enterprise storage systems to support VDI that can dissuade enterprise organizations from moving forward with their plans for VDI. So while they recognize the benefits of introducing VDI into their environment, they yet lack a storage solution that both meets VDI s high-end requirements and is affordable. Further, the process of identifying an appropriate storage solution that meets all of VDI s high-end demands so they can overcome these objections to deploying VDI is not trivial. VDI s Conflicting Storage Demands The average non-virtualized desktop needs about 20 GBs of storage to support it. So as enterprise organizations look to consolidate hundreds, thousands, tens of thousands or even hundreds of thousands of desktops, they need a storage solution that scales to meet those storage capacity demands. Consider: VDI Useable # of Desktops Storage Capacity Needed GB TBs 1, TBs 10, TBs 100,000 2 PBs So if storage capacity was the only concern, storage solutions exist that can economically meet storage demands for up to about 1,000 users. It is when the 1,000 user threshold is approached and breached that the cost of a storage solution that offers sufficient storage capacity becomes much more expensive. However, storage capacity is not the only concern for these organizations. Virtualizing all of these desktops and aggregating their data creates performance demands that do not exist on individual 2010 DCIG LLC. All rights reserved. p. 2

5 desktops. Log on boot-storms occur when hundreds or thousands of users log on at the same time and attempt to access the storage associated with their desktop. It is during these periods of time that the ratio of reads to writes can climb to 20:1 or higher (eg. for every 20 read I/Os, there is only 1 write I/O.) The twist is that this high ratio of reads to writes only exists for the first 30 minutes or so of each business day. Once the boot-storm passes, service providers that have already implemented VDI for their clients report that I/O demands swing more heavily towards writes after the initial boot storm. They see write I/O activity minimally starting at a split between reads and writes with some of their VDI clients reaching write ratios that are as much as 80% of the total I/O activity. 2 They have also found that the number of I/Os per virtual desktop ranges from 3 IOPS for a light user to about 20 IOPS for a power user. So an enterprise environment with 1000 users, assuming an 80/20 split with 80% being light users and 20% being power users, could average 6400 IOPS during the day of which up to 80% (or over 5000) of those IOPS being write I/Os. These swings in I/O traffic from high levels of read activity first thing in the morning to high levels of write activity for the remainder of the day dictate that enterprise organizations identify a storage architecture that can dynamically and economically adapt to the demands of a VDI. The Seven Keys to Selecting the Right Storage Architecture for Enterprise VDI Environments There are seven keys to selecting the right storage architecture for an enterprise VDI implementation. These seven keys are: Key #1 Cost-effective Scale Out of Storage Capacity Consolidating and centralizing all desktop data will clearly require more storage capacity and the best way to deliver it is in the form of a networked storage solution. The key is to obtain a solution that is architected to support the cost-effective scaling of storage capacity. In other words, as more storage capacity is added, the networked storage solution should not become exponentially more expensive. Rather the cost to add each new GB of storage capacity should remain flat or even decrease to take advantage of the constant increases in HDD density and compares favorably with the price per GB of desktop HDDs. Equally important, as new capacity is added, it needs to scale in such a way that other enterprise storage system features such as availability, data protection, performance and reliability continue to satisfy enterprise expectations. Key #2 Flexibility to Introduce the Right Tier of Disk Simply adding more of the same tier of disk drives to a storage system is not enough. The storage system needs to support the addition of any tier of high performance disk that enterprises may need. These tiers should include FC, SAS, SATA and even solid state drives (SSDs). By way of example, SSDs may be needed to provide the high performance that enterprises are likely going to need to address their morning bootstorms. Economical high capacity drives (SATA) will be called upon as a means to cost-effectively consolidate all enterprise data. Finally FC and/or SAS drives may be needed to handle performance-sensitive application workloads that cannot justify the expense of SSDs. Key #3 Automated Data Placement Putting different tiers of disk in a storage system does not automatically mean that the right data ends up on the right tier of disk. Why should desktop data that has the CIO of National Retailer Gets a VDI Wakeup Call A CIO of a nationwide US consumer electronic goods and services chain recently discovered that the initial savings he experienced when deploying a VDI were quickly eaten up by the unexpected demands that his virtual desktop users were placing on his backend storage. He had virtualized about 3000 desktops and realized savings in the hundreds of thousands of dollars. However, the consequences of not putting in place an appropriately configured storage solution for his VDI deployment soon came back to haunt him. Every morning from 8:00 am until about 8:30 am, his phone lit up with calls from frustrated users who could not access their virtual desktop. The problem was that his 3000 VDI users were all booting their virtual desktops and trying to log on at approximately the same time. This was overtaxing the storage behind the VDI server, creating frustrated users and putting his VDI deployment in jeopardy. The solution in his case was to purchase a half million dollar storage system that offered high performance solid state drives (SSDs) so his users had the same log on experience that they had come to expect when using desktops with local HDDs. While this solution alleviated his problem, it negated all of the initial savings that he had realized from his VDI deployment DCIG LLC. All rights reserved. p. 3

6 highest performance requirements reside on the same storage as those which are relatively inactive? The answer is it should not; or at least it should not if it is needed by other applications. By selecting a storage system that supports automated data placement, it can place data that is less frequently accessed on higher capacity, more economical SATA disk drives. Conversely, more frequently accessed data may be placed on faster, more expensive FC, SAS or even SSD drives. Ideally the storage system should also provide the option to set policies such that for known periods of high activity such as monthly, quarterly or year-end accounting periods, data can be pro-actively moved from slower to higher performing disk prior to the application needing it. Then once the application s need for the data is complete, the data can then again be moved back to slower disk so the higher performing disk is freed for applications that need it. Key #4 Storage Controllers that Scale Out It is easy for enterprises to focus on how much storage capacity a storage system holds and what tiers of disk drives it supports. However the number of storage controllers it supports may actually be a better indicator of how well a storage system scales to handle the increases in storage capacity and performance that VDI needs. Many storage systems only support two controllers with limited amounts of cache which account for the majority of money spent on networked storage systems. So even if they can scale to handle more cache, once those two controllers are saturated from a performance perspective, the enterprise will need to buy another storage system that functions as a separate unit both logically and physically. This is not the linearly scale out configuration that VDI deployments need as this dual controller architecture results in both increased cost and complexity. VDI environments need storage architectures such that storage controllers can scale out linearly and still grant access to the same pool of storage that the controllers already in their environment can access. This eliminates the complexity of managing multiple pools of storage, enables more linear storage growth and makes it more cost-effective to grow the storage environment. Further, more storage controllers enables the introduction of more memory which can also be leveraged to mitigate the impact of early morning boot storms. Key #5 Supports NAS Storage area networks (SANs) are sometimes viewed as the preferred method for implementing networked storage in VDI deployments. However NAS has come Beware VDI s Networked Storage Costs Reduced desktop hardware, software and support costs are often cited as the primary reasons to adopt VDI. But what many are discovering is that networked storage is becoming the highest cost in a VDI implementation and may exceed the savings that VDI provides. Consider: Networked storage on a per GB basis is approximately 10x the cost of internal desktop drives. Network storage systems are frequently used in VDI deployments because of their availability, data protection, performance, reliability and scalability features. However these features come at a premium to what internal HDDs in desktops cost. Value of data stored on desktops. The value of data on enterprise desktops has been notoriously hard to quantify so absent any metric, organizations ascribe to it the same value as the cost of the desktop HDD. This viewpoint tends to carry over when pricing the storage system that will hold the data once the desktops are virtualized making it difficult to find a price competitive storage solution. New expectations for data protection and application availability emerge once data is consolidated and centrally managed. Users are accustomed to taking responsibility for protecting whatever data is on their hard drives though few if any ever took the initiative to do so. This changes once VDI is implemented as it becomes the responsibility of the corporate IT team to protect the data and ensure its availability which adds new costs to the solution. Networked storage systems typically do not scale out cost effectively. Networked storage systems are typically designed to handle a very limited number of application servers with predictable patterns in storage capacity growth and application performance. Networked storage systems in VDI deployments may need to account for hundreds, thousands or even tens of thousands of virtual desktops, meet sporadic spikes in performance, and provide large amounts of storage capacity. Systems that provide these services can easily run into the hundreds of thousands if not millions of dollars DCIG LLC. All rights reserved. p. 4

7 to be recognized by many storage professionals as a superior choice to SAN for VDI deployments. Part of this has to do with how VDI platforms such as VMware View manage NAS. VMware View can natively manage volumes presented by networked attached storage arrays using either NAS or SAN which helps to put NAS on an equal footing with SANs in that respect. If anything, VMware View actually prefers NAS since it by default thinly provisions NFS presented volumes. The advantages of using NAS over SAN become more pronounced for enterprises that are scaling to thousands or tens of thousands of VDI images. In this case the I/Os of individual virtualized desktops are primarily random and small which makes them better suited for NAS. Finally NAS is better designed to handle shared access to files which is essentially what desktops become once they are virtualized. In this environment, NAS avoids some of the locking issues that can occur when SANs are used in enterprise VDI deployments. 3 Key #6 Integrates with Existing VMware Management Tools The centralized management and protection of virtualized desktop images and their data are essential to effectively delivering on the promise of a VDI. However this centralized management strategy also needs to extend to the networked storage solution used in support of the VDI. This necessitates that the storage solution provide APIs that natively integrate with popular VDI management tools such as VMware vcenter. In many enterprises, vcenter has become a de facto standard that virtual server administrators use to manage their virtual environments so they already have a comfort level using this tool. Since the discovery, provisioning and management of the networked storage that the virtual desktops use often becomes the responsibility of these administrators, they will want the flexibility and freedom to manage this storage from the vcenter console. Key #7 Efficiently Stores Data How efficiently a networked storage system manages data stored on it is rapidly becoming a determining factor as to whether or not an enterprise can afford to deploy it for use in their VDI environment. Initial findings of those who have already deployed VDI suggest that they are replete with duplicate data. In these circumstances, storage technologies such as deduplication remove duplicate data and thus enable enterprises to minimize the total amount of storage capacity that their VDI deployment consumes while creating new opportunities to cost-effectively store this deduplicated data on networked storage systems. Symantec VirtualStore Satisfies These Seven Key Requirements for Enterprise VDI Deployments Enterprise VDI deployments are prompting a dramatic shift in what enterprise customers expect and demand from the networked storage systems that they implement in support of VDI. In these environments they cannot justify the deployment of pricey enterprise class systems that inefficiently use storage capacity, scale ineffectively and that may lack the availability of the best storage protocol for VDI. It is for reasons like these that organizations should look to storage architectures such as Symantec VirtualStore that is optimized for the specific requirements that enterprise VDI deployments possess. VirtualStore is at its core a clustered NAS solution based upon Symantec Veritas Cluster File System and Storage Foundation. VirtualStore has been optimized and tuned so it provides the turn-key deployment, simplicity of management and full breadth of storage features that enterprises need to affordably and effectively deploy a networked storage solution in support of their VDI implementation. VirtualStore: Virtualizes any tier of storage SSD, FC, SAS or SATA so enterprises can deploy whatever storage that they need. Clones desktop instances as approximately 80% of an OS boot image is redundant across desktops. Tracks duplicated blocks in desktop clones and caches them so that after the desktop is booted up for the first time, all subsequent desktops that boot up do not need to access the storage array to retrieve the OS data. Instead, subsequent desktops will fetch the common blocks directly out of cache on the VirtualStore node. This avoids generating an overwhelming amount of read load to the storage array. Gives administrators the freedom to set policies so data can be dynamically moved to the appropriate tier of storage based upon its frequency or infrequency of usage. Data can even be proactively moved to a specific tier of storage in anticipation of increased or decreased application demand for it. Supports up to 32 controllers and over 2 PBs of storage in a single logical configuration. Storage 2010 DCIG LLC. All rights reserved. p. 5

8 capacity or performance can be scaled independently to meet changing and growing application demands. Provides the availability, data protection and reliability features that enterprises desire in this solution while keeping high storage costs at bay. VirtualStore runs on commodity server hardware and can virtualize any commodity storage so enterprises are not forced into a specific vendor s hardware product in order to scale their storage capacity or performance. Integrates with vcenter management console for rapid cloning, provisioning, and management of Virtual Machine images. Has deduplication on its roadmap (planned for next release) so with most users still in early stages of VDI adoption, it should be available when the need for it arises. Further, VirtualStore is implementing deduplication in such as way that those who adopt it now will still be able to deduplicate their VDI once it is available. It is for reasons like these that enterprises need networked storage architectures that are specifically designed to meet the needs of VDI implementations. Symantec VirtualStore reflects this new type of storage architecture that has the enterprise storage features that enterprise VDI implementation demand while keeping the cost per GB for storage at a price point that is on par with internal desktop HDDs and the cost per VDI can be driven to a fraction of the per desktop cost. 1. Imprivata. Global Survey Shows Growing Demand for Virtualized Desktop Environments. 18 Aug Web. 28 Aug Van Brug, Herco. VDI & Storage: Deep Impact. PQR. 29 Mar Web. 29 Aug Crump, George. Dealing With VDI Storage Management Issues. Storage Switzerland. 18 June Web. 29 Aug About DCIG DCIG analyzes software, hardware and services companies within the storage and ESI industries. DCIG distributes industry, company and product analysis by way of viral marketing and community building using the burgeoning BLOG infrastructures created worldwide. DCIG, LLC 7511 Madison Street Omaha NE dciginc.com 2010 DCIG, LLC. All rights reserved. All other brands or products are trademarks or registered trademarks of their respective holders and should be treated as such. The information, product recommendations and opinions made by DCIG LLC are based upon public information and from sources that DCIG LLC believes to be accurate and reliable. However since market conditions change, the information and recommendations are made without warranty of any kind. All product names used and mentioned herein are the trademarks of their respective owners. DCIG LLC assumes no responsibility or liability for any damages whatsoever (including incidental, consequential or otherwise) caused by one s use or reliance of this information or the recommendations presented or for any inadvertent errors which this document may contain. Any questions please call DCIG LLC at (402)