DOUBLE
VIRTUALIZATION
BENEFITS WITH
STORAGE FOR
VIRTUALIZED
ENVIRONMENTS
With passing economic climates, IT organizations have become more sophisticated and no longer purchase technology for its own sake. They must align technology with business goals of increasing revenues, reducing costs and minimizing risks.
One way organizations are achieving this alignment is through server
virtualization, which eliminates siloed servers and overprovisioning by allowing multiple virtual machines to share the same physical server. Because VMs can be dynamically allocated as needed, organizations can reduce the total number of servers and better utilize server resources, thereby reducing acquisition, datacenter, management and energy costs. Until recently, most of the attention has been focused on servers, yet there is an equal savings opportunity waiting when using enterprise-class storage in virtualized operating environments. As IT has increasingly implemented server virtualization, it has neglected efficient storage virtualization. Storage represents a rapidly growing investment for IT and efficiently virtualizing storage resources represents an opportunity to double the benefits data centers achieve through server virtualization.
As organizations seek to implement storage virtualization, they can choose scale-up or scale-out virtualization. Scale-up virtualization achieves scalability by using more expensive hardware with better performance and higher capacity. This means organizations must replace storage with higher capacity units as their requirements grow. Scale-out virtualization enables IT to add purpose-built, enterprise-class storage units with the right features in an incremental manner as their storage requirements increase.
This white paper describes how scale out storage - which is managed in the server stack-enables IT to better align IT resources with business requirements by:
• Facilitating top-line growth through the ability to incrementally and quickly add inexpensive server resources
• Reducing costs of acquisition, operations, datacenter facilities, energy and system management via storage consolidation
• Minimizing risk through business continuity capabilities.
This paper will also describe how Nexsan storage arrays seamlessly support storage management capabilities built into Microsoft Hyper-V, VMware, Citrix and Symantec virtualization solutions.
CIO
TECHNOLOGY PRIORITY2010 PRIORITY2009
Virtualization 1 3
Cloud Computing 2 14
• Exploding Infrastructure Growth
• Consolidation Drives Virtualization
• Virtualization is the on ramp to the Cloud
CIO
THE NEED TO ALIGN IT WITH BUSINESS OBJECTIVES
IT departments are no longer bringing in the latest and most advanced capabilities, but rather aligning technology in their IT infrastructure with the objectives of the business. This means that IT must support business efforts to:
• Increase revenues - IT must implement software applications necessary to
grow the business and support these applications with a highly scalable and easy-to-manage IT infrastructure.
• Reduce costs - IT must improve the efficiency of the IT architecture and
management infrastructure to minimize both acquisition costs (CapEx) and operational costs (OpEX).
• Minimize risk - IT needs to minimize the risk of downtime by implementing
business continuity and disaster recovery solutions.
THE ADDED VALUE OF STORAGE VIRTUALIZATION
As IT has raced to implement server virtualization, it has largely ignored storage even though it represents a significant and rapidly growing investment for IT. Despite technologies designed to increase storage efficiency, enterprise data continues to expand at more than 40% per year. At the height of the recession in 2009, at the height of the recession, organizations purchased 39% more storage capacity than in 2008, whereas the compounded capacity growth was 60% to 70% in previous years. Gartner finds that storage hardware purchases account for 36% of the typical IT purchasing budget. IT organizations can extend the gains from server virtualization substantially by virtualizing storage.
Storage virtualization has the potential to double the data center cost savings that organizations achieve through server virtualization. Forty percent of data center costs come from servers. Virtualization makes these servers 50 percent more efficient, which means that the total savings to the data center as a whole from server virtualization is 20 percent. Another approximate 40 percent of data center costs come from storage. IT has the opportunity to save 50 percent of storage costs through storage virtualization and optimization. Using both server and storage virtualization in tandem, data centers can reduce total data center costs by an estimated 40 percent or more.
NO VIRTUALIZATION • Without virtualization a LUN
representing a volume is owned by a single OS
WITH VIRTUALIZATION • When virtualized, multiple
OS’s may share single or multiple volumens that span multiple LUNs
STORAGE
VIRTUALIZATION
BASICS
Volume
A critical aspect of optimization is management. Today, storage throughout the organization typically isn’t centrally managed or virtualized. IT might have raised floor environments or small storage sites for individual departments, where they use a few arrays without sophisticated storage management tools or skills. Organizations often overprovision storage for each of these siloed environments to ensure adequate storage capacity.
Storage virtualization, like server virtualization, allows organizations to consolidate storage resources by adding an abstraction layer of software that hides physical storage devices from the user and allows all devices to be managed as a single pool. Data is represented differently from where it physically resides and is managed as a logical unit.
Today’s virtualized environments come with storage management solutions that can greatly simplify and improve the management of these virtualized storage resources. Capacity management is available to help IT allocate and utilize storage efficiently. Performance management capabilities allow administrators to analyze and balance performance. Data protection is available to meet recovery performance objectives measured as RTO/RPO (recovery time objective/recovery point objective) management. Solution approaches such as point-in-time copy management, backup, restart, recovery, deduplication, protection from hackers and user authentication are all used. SAN mesh management is available as well as maintenance planning and activity logs.
Benefits of consolidation through storage virtualization and advanced storage management include:
• More efficient storage utilization, which not only reduces acquisition costs, but also allows IT to reduce data center complexity since devices that were formerly isolated or underutilized can now dynamically provide capacity for processes with the most demand for storage.
• Fewer storage devices, which take up less expensive square footage in the data center and reduce energy consumption.
• A reduction in storage units, resulting in less time must be spent on maintenance.
• Improved business continuity and disaster recovery through data protection features available in storage management solutions.
• Virtualization Management
ARRAY MANAGED
VIRTUALIZATION
• Array Management
• Capacity Management
• Data Read and Write Performance Management
• Protection Architecture Management
• Maintenance and Planning Virtual Servers
TWO METHODS OF STORAGE VIRTUALIZATION
IT organizations can implement storage virtualization using two methods: array managed (also called scale-up) or stack (server) managed (also called scale-out). With array managed virtualization, IT meets requirements for higher performance and virtualized higher capacity by replacing existing storage with faster, higher capacity storage devices. A stack managed system scales by adding storage nodes to the network where a virtualization solution typically already exists within the stack.
ARRAY MANAGED VIRTUALIZATION
Today, most organizations use array managed storage virtualization solutions. With array managed systems, storage management features are built into the array controller. When the array reaches the upper limits of storage it can manage, IT either replaces the existing array with a larger unit or adds another storage array. Either way, IT ends up paying for all of the management capabilities in the controller each time they upgrade or add a storage array. Since embedded storage management comprises the bulk of the cost for these storage systems, this adds considerable redundant expense, especially if a stack virtualization solution already exists, (See diagram on page 4).
STACK MANAGED VIRTUALIZATION
With the onset of server virtualization and storage resource managers, IT now has the option of managing storage from the server stack. Rather than having to purchase arrays that include redundant storage management capabilities within each storage array controller, a storage array can include a thin layer of software, leaving the bulk of storage management capabilities to the virtual server stack containing:
• Hypervisors that include storage management features, allowing storage administrators to run multiple, concurrent instances of a VM server and access the same VM storage or advanced features such as thin provisioning.
• SRM (storage resource management) software - Modern SRM tools are used in conjunction with or integrated with hypervisors to provide an end-to-end view from the VMs and servers to the storage arrays. SRM capabilities include automating allocation processes, monitoring changes and alerting users of configuration changes that violate best practices or policies. SRMs also provide capabilities such as storage tiering, migration and Quality of Service that ensure utilization and performance efficiency. They are also used in high-availability environments to
• Virtualization Management
• Storage Resource Manager
› Array Management
› Capacity Management
› Data Read and Write Performance Management
› Protection Architecture Management
› Maintenance and Planning
STACK MANAGED
VIRTUALIZATION
• Array Setup and Provisioning Virtual Servers
It is this ability to manage storage in the server stack that enables scale-out stack managed storage. Because all storage is managed centrally, IT can horizontally add new storage nodes without the need for storage arrays with special controllers containing storage management software and added expense. The central storage stack managed system can manage hundreds or thousands of nodes and make them act like a single system. In this way, stack managed storage displaces large, costly enterprise equipment with an easily sized, highly scalable pool of inexpensive, purpose-built, enterprise-class storage devices. Common savings in cash flow can easily be 50% NPV over 5 years with a payback of less than a year.
THE BUSINESS VALUE OF SCALE-OUT VIRTUALIZATION
With scale out or stack managed virtualization, IT organizations can easily align storage to the needs of the business. In particular, stack managed storage offers the following benefits:
Facilitates Growth
As a business grows, data storage requirements increase. Stack managed storage makes it inexpensive and fast to scale, meeting growing storage requirements. IT can simply add new purpose-built, enterprise-class storage incrementally as needed. Moreover, IT does not need to migrate to a new system or even take the system down when adding new storage hardware. Instead, they can simply add new storage components as needed, keeping storage up and running and dynamically shifting some of the workload to the new devices as they become available. This reduces the time to deploy new servers and perform data backup and recovery.
Reduces Costs
Instead of having storage marooned in separate, directly connected units, Stack Managed storage virtualization makes storage available to all VMs from a common pool that can be dynamically allocated as needed. This reduces costs in a number of ways. It improves storage utilization while reducing the total amount of storage required. Having fewer storage devices reduces acquisition costs, lowers the amount of data center space/cost and cuts energy consumption. In addition, because stack managed virtualization allows IT to manage all VMS and storage from a single management interface on the server, it greatly reduces the complexity of managing the data center.
STORAGE
VIRTUALIZATION
MAPPED TO ARRAY
NO VIRTUALIZATION
Volume
LUNs from RAID Group
Nexsan E-Series Storage
Minimizes Risk
Storage and server virtualization with an SRM provides a wide range of capabilities that meet business demands to minimize the risk of downtime by improving business continuity and enabling disaster recovery. For example, Nexsan offers Assureon archive storage to provide business continuity and disaster recovery that offers compliant-level privacy, integrity and longevity; self-auditing, self-healing file management; and enterprise-class manageability, scalability and energy efficiency. With its security capabilities, Assureon perfectly augments a virtualized storage environment to provide secure cloud services.
HOW NEXSAN IMPLEMENTS STACK MANAGED
VIRTUALIZATION
Nexsan storage arrays, such as its Beast and Boy families or the Nexsan E-Series, can be managed in the stack and used in a scale-out stack managed storage environment. All Nexsan arrays are ultra reliable and deliver high capacity, high performance and energy efficiency in a flexible software architecture that can be integrated into and used transparently with a Windows Server environment.
NEXSAN AND MICROSOFT
Microsoft offers a number of capabilities for managing Virtual Machines and Virtual Storage and Nexsan’s management software integrates with these Microsoft capabilities. It is through this integration with Microsoft virtual storage management capabilities that Nexsan supports not only Microsoft’s Hyper-V virtualization system but also virtualization systems from other vendors including VMware, Citrix and Symantec.
Hyper-V is Microsoft’s hypervisor-based virtualization system for x86-64 systems. The Microsoft Server 2008 operating system comes with the Microsoft
Management Console (MMC), which provides an interface through which administrators can configure and monitor the server system. The management console can host one or more Component Object Module components called snap-ins. Hyper-V is one of these snap-in modules. Other snap-in modules include SAN Storage Manager. WITH VIRTUALIZATION Volume SSD SAS SATA Hypervisor OS OS OS
LUNs from RAID Group
Swap Swap Swap OS OS OS App App App Quality of Service Mapped to Storage Tier
Nexsan E-Series Storage
STORAGE
Microsoft also offers a set of application programming interfaces (APIs), called Microsoft Virtual Disk Services (VDS), that provide a single interface that storage management applications run as MMC snap-ins and can be used to manage hardware and disks as well as create volumes on those disks. VDS manages storage devices using so-called “providers”. Built-in VDS software providers from Microsoft enable IT to manage disks and volumes at the operating system level. Hardware providers supplied by storage hardware vendors enable IT to manage specific hardware RAID arrays. Hardware vendors can write a VDS hardware provider that translates the general purpose VDS APIs into specific instructions for their own hardware.
VDS simplifies storage management because storage management applications no longer need to take into account the specific hardware being targeted. Instead, IT can use a single storage management application to manage any hardware that has a VDS hardware provider.
Nexsan supports these Microsoft storage management capabilities by integrating with MMC and by creating VDS hardware providers for its storage arrays.
MMC INTEGRATION
All Nexsan storage products come with an embedded Web-based utility that enables the management of multiple storage arrays from a single interface. The Nexsan storage management utility integrates with the Microsoft MMC. This integration allows IT administrators to invoke Nexsan’s management software while working with storage-related MMC tools.
The Microsoft/Nexsan integration is unique in that it allows administrators using MMC or other storage management tools within the MMC environment to “right click” and see a complete set of array properties (e.g. topology, rack, array, LUN) that they can use to configure and manage their RAID arrays. Without this ability, administrators would have to dig this information up from different spreadsheets, LUN maps, screens and so on. This integration reduces complexity, increases efficiency, minimizes mistakes and improves administrator productivity.
VDS INTEGRATION
Nexsan has created a hardware provider called the Nexsan VDS software. With Nexsan VDS software, IT can use the Microsoft MMC to add Nexsan arrays to the storage pool by configuring Nexsan RAID sets, creating LUNs, assigning capacity to servers and implementing different service levels. IT can even migrate data from old storage systems to new Nexsan storage systems.
BUSINESS APPLICATIONS: • Data Mining • Backup • Testing Storage Management Applications SAN-Hardware Specific
NEXSAN/MICROSOFT
INTEGRATED
MANAGEMENT
CHALLENGES:• Multiple vendor specific consoles
• No Application Participation in storage events • No simple way to access and move data
MANAGE STORAGE WITH VDS BENEFITS:
• Standardized Storage Management • Scripting and Automation • Easy Setup and reconfiguration • Reduced Training
MANAGE DATA WITH VSS BENEFITS:
• Easy copy or move large amounts of data • Makes applications storage-aware • Fast, high-fidelity backups
LUNs from RAID Group
Nexsan E-Series Storage
Web Servers
VMWARE AND NEXSAN
Nexsan works with VMware’s management capabilities through their mutual support for Windows Server 2008. The VMware environment requires an appliance/ server that runs vSphere cloud operating software and a management console, VMware vCenter Server. vCenter provides centralized control and visibility at every level of the virtual infrastructure. VMware also offers vMotion, which leverages the complete virtualization of servers, storage and networking to move an entire running virtual machine instantly from one server to another (to eliminate downtime when performing maintenance or migrations or optimizing the system). Because
vCenter and vMotion run on top of and use Windows Server 2008 (which includes MMC) to manage the virtual operating environment AND because Nexsan arrays are directly integrated with Microsoft’s VDS, VMware users can simplify SAN administration using a single-pane-of-glass interface.
Nexsan also includes capabilities that simplify storage array configuration using vCenter. When IT employs vCenter to configure new storage capacity, vCenter is initially blind to storage. When an ESX or ESXi host (which is managed by that vCenter server) starts, it has no understanding of what storage has been mapped. To perform that mapping, MMC or SAN Manager must be used to create and map the volume to the ESX/ESXi host. Because MMC or SAN Manager use VDS to perform that mapping, the mapping process is automated for Nexsan. In contrast, systems that do not support VDS would require administrators to manually create and map the volume or use proprietary management console software from another array vendor along with spreadsheets and maps. In addition, Nexsan supports key VMware performance enhancement capabilities-Asymmetric Logical Unit Access (ALUA) and Round Robin with subset:
• ALUA support-To optimize performance, systems with multiple controllers need to handle the dual issues of array ownership (active service processes) and SAN load balancing (active ports). Through Nexsan’s implementation of ALUA, host systems with advanced MPIO software, such as VMware’s ESX and ESXi 4.1 along with Windows Server 2008, can access a Nexsan storage array and discern the subtle but important difference between an active port and an active port on an active service processor. Because I/O requests are sent only to active service processors this enables optimal performance and avoids the overhead of switching controllers.
• Round Robin with Subset. Conformance to VMware’s 4.1 Round Robin with subset improves performance by 20% compared to the performance of vSphere
ARRAY MANAGED
CITRIX AND NEXSAN
Unlike VMware and Hyper-V, if a hardware provider is not available, there is no Citrix built-in software provider to perform replication services. Citrix has partnered with DataCore to provide these services.
NEXSAN AND SYMANTEC
Symantec offers the Veritas Operations Manager as a comprehensive management platform for Storage Foundation and Cluster Server environments. This environment includes Veritas CommandCentral Storage, which provides a single view of the full storage stack from application to spindle, enabling storage capacity management, centralized monitoring and application-to-spindle mapping. Because these capabilities work from the file system layer, Nexsan storage arrays work in this environment with no modifications. Nexsan is currently certifying products with Symantec.
SUMMARY/CONCLUSION
Nexsan storage arrays are designed to be managed in the stack and used in a scale-out stack managed virtualized storage environment. These solutions can be managed seamlessly within Microsoft Hyper-V, VMware, Citrix and Symantec virtualization management solutions. By using Nexsan storage in these environments, IT can better align storage resources with business requirements. Specifically, they can facilitate top-line growth by scaling storage rapidly and inexpensively to meet the needs of growing businesses, reduce costs by requiring less storage, and reduce the associated costs of system management, data center space and energy. With robust business continuity, Nexsan solutions also minimize the risk of downtime.
ABOUT NEXSAN
Nexsan® is a leading independent provider of disk-based storage systems
purpose-built and priced for the mid-market, offering industry-leading reliability, space and power efficiency. Overcoming the challenges of traditional storage, the company’s disk-based systems reduce the complexity and cost of storage with easy-to-use, efficient and enterprise-class features, delivering a different kind of storage experience. For more information, visit the company’s website at www.nexsan.com.
