Storage virtualization gets downsized

Pooling smaller storage networks is hot now, though a grander multivendor vision endures

Small is beautiful, claims the title of the classic 1973 economics text by E.F. Schumacher. The same might be said for storage virtualization. A couple of years ago, vendors discussed virtualization in sweeping terms. The objective was to take storage arrays from multiple vendors and present them as a unified, logical storage pool. Government deployments of virtualization technology, however, don't always conform to that ecumenical vision.

Virtualization in a single storage product, a concept as old as Redundant Arrays of Independent Disks (RAID), has become commonplace as more agencies adopt the technology. Installations may occur on a relatively small scale, as departments or remote locations seek improved storage efficiency.

But industry and storage managers have not abandoned virtualization as a multivendor solution. The number of products aiming to tackle this chore is growing, which some observers say represents true virtualization. Virtualization's benefits will have the greatest impact in large-scale, heterogeneous settings, they say. Those benefits include improved use of storage devices and ease of management.

"The big win for virtualization is where the customers have made very large investments and have really driven the complexity of their storage environments," said James Jackson, business development manager at iGov, a federal solutions provider.

However, size provides only one variable in virtualization's expanding scope (see "Many faces of virtualization," Page 30). Solutions can support Fibre Channel storage-area networks (SANs), Internet SCSI SANs or both. Virtualization also touches network-attached storage. Virtualization varies, but the primary solutions are based on hosts, arrays or networks.

Overall, virtualization is rapidly becoming a standard feature of storage solutions. "The industry leaders have already adopted storage virtualization — and I would call it storage simplification — into their shipping products," said Jay Brummett, chief technology officer for Ogden, Utah.

Virtualization in a box

Brummett said the city of Ogden exemplifies an organization that has grappled with islands of storage — direct-attached storage, external RAID and other varieties. The city's storage devices were either significantly underutilized or nearly out of capacity. Overall, storage utilization was at about 50 percent, yet the city was running out of storage in some areas.

"The problem that I faced was that I never had the storage head space where I needed it," Brummett said.

Ogden responded by installing an IP-based SAN from LeftHand Networks. The 10-terabyte installation is a midsize SAN. It consists of Network Storage Modules, arrays that use Advanced Technology Attachment or Serial ATA drives.

The company's SAN/iQ software provides the virtualization element. SAN/iQ permits network administrators to configure the arrays as a virtual storage pool that they can manage through a centralized console.

Since deploying the new SAN, Ogden has improved storage utilization and left room to grow. "Currently, we manage our storage at a controlled 75 [percent] to 80 percent utilization," Brummett said.

LeftHand's brand of virtualization also simplifies administration. Brummett said adding storage into the SAN fabric is a matter of snapping an additional storage module into the architecture. Moreover, storage can be added or removed without disrupting users.

The Navy's Surface Combat Systems Center (SCSC) lab obtained similar results with a single-vendor virtualization solution. SCSC, based on Wallops Island, Va., tapped Xiotech's Magnitude 3D virtualized Fibre Channel SAN. The lab's main objective was flexibility.

The center tests shipboard systems before deploying them, evaluating up to six warship configurations daily. Before SCSC started using Xiotech's SAN, ship crews would arrive at the lab with disk drives bearing the configuration they needed. Some configurations required as many as 65 drives.

Les Martin, tactical systems engineer at SCSC, decided the media situation wasn't sustainable.

"You can never buy enough media, much less physically store it," said Martin, who describes SCSC as a small to midsize enterprise.

He said the lab needed a storage solution that met the Navy's open architecture requirements and dynamically managed all the available storage.

Now, Xiotech's virtualization box can house the dozens of possible shipboard configurations, Martin said. Drives contained in the Magnitude 3D arrays can be carved into virtual storage pools, or VDisks. The lab specifies a VDisk's capacity, and Magnitude 3D allocates unused blocks on each drive. To increase a VDisk's capacity, additional blocks are allocated. Each drive contributes the same amount of unused space, maximizing utilization.

"With storage virtualization, you use only the storage you need when you need it," Martin said.

The improved utilization helps the Navy avoid unnecessary hardware costs. Another benefit of virtual storage is that SCSC employees can change failed drives without sending for a vendor technician. That's an important consideration given SCSC's remote location on Virginia's Eastern Shore.

Multivendor push

Some small to midsize organizations have migrated to a virtualized SAN from a hodgepodge of storage devices. But that may not be an option for larger enterprises running expensive storage arrays from more than one vendor. Those organizations seek virtualization to protect their storage investment and manage complexity.

Tools capable of pulling off this brand of virtualization represent a relatively recent development. "Some of this technology has only been around for the last couple of years," said John Martien, senior system engineer at iGov. "Before then, you could not move from one vendor's array to another vendor's storage array and be able to move that data around."

Martien said iGov has standardized on IBM's SAN Volume Controller for multivendor virtualization. SAN Volume Controller can create a unified storage pool by tapping into IBM's arrays and those from EMC, Hewlett-Packard and Hitachi Data Systems, among others.

SAN Volume Controller, available since 2003, has been deployed at more than 1,000 customer sites, said Ron Riffe, an IBM storage software strategist. He noted a fairly good uptake of virtualization technology in the federal market.

SAN Volume Controller is an example of in-band virtualization, in which a hardware appliance resides in the data path between storage and servers. DataCore Software's SANsymphony and FalconStor Software's IPStor also fall into this appliance category.

Multivendor virtualization also takes place at the host, or server, level through products such as Veritas Software's Volume Manager, part of the company's Veritas Storage Foundation. Matt Fairbanks, director of product marketing for the company's storage and server management group, said one government virtualization customer has seen a 204 percent return on investment in three years and a 25 percent reduction in time spent on storage-management tasks.

Virtualization also occurs on the storage array itself, though this has traditionally been a single-vendor affair. But last September, Hitachi unveiled its TagmaStore Universal Storage Platform, which performs multivendor virtualization through the array's storage controller.

The TagmaStore solution has completed virtualization testing with storage products from HP, IBM, Sun Microsystems and EMC, according to company officials.

HP and Sun are marketing TagmaStore products under their labels, said Dan Smith, enterprise technology consultant at GTSI.

Other recent virtualization developments focus on networks. Network Appliance debuted its V-Series line in March. It covers high-end and midrange arrays from Hitachi and IBM and HP's high-end products.

NetApp is working on support for EMC and midrange HP arrays, said Jeff Hornung, NetApp's vice president of enterprise file services and storage networking.

"Virtualization systems are only as good as the breadth you can virtualize," he said.

EMC entered the network storage virtualization space earlier this month with Invista. The product will initially run on intelligent SAN switches from Brocade Communications Systems and Cisco Systems. It will also operate on McData's intelligent SAN switch, which is slated for availability next year. Invista supports arrays from IBM, HP, Hitachi and Sun.

Dennis Hoffman, vice president of software marketing at EMC, said the company's virtualization approach lets the switch route data directly to storage for an out-of-band solution. He said out-of-band virtualization offers scalability and performance benefits. He said he has briefed two or three federal agencies in recent weeks on the technology.

Cisco, meanwhile, is helping EMC and other vendors push virtualization to the switch with its MDS 9000 Storage Services Module. EMC's Invista will ship on the module in the third quarter, according to Cisco officials. The module already ships with Veritas' Storage Foundation for Networks, which provides heterogeneous storage pooling.

Virtualization comes in various flavors. But the objective remains the same: Get the most out of storage resources.

Many faces of virtualization

Virtualization extends in many directions these days. One is downward. Virtualization products associated with enterprise-class storage-area network (SAN) installations have been scaled down to deal with smaller deployments.

For example, DataCore Software debuted its SANsymphony cross-platform virtualization product in 2000. The product targets enterprise storage requirements. Last year, the company rolled out SANmelody for smaller organizations.

Since the beginning, DataCore's expertise has been in high-end virtualization in the enterprise market, said George Teixeira, the company's chief executive officer. SANmelody, however, aims to "bring the high-end enterprise features down to the level of the mass market," he added. SANmelody targets Internet SCSI storage-area networks but also supports Fibre Channel.

From a pricing standpoint, DataCore can field a SANmelody solution for as little as $1,178, although installations will typically run $5,000 to $15,000. That compares with $50,000 to $80,000 for SANsymphony, Teixeira said.

Virtualization's shift to SAN switches represents another important technology direction. EMC's Invista product provides a case in point. An initial configuration of 64 terabytes costs $225,000, including hardware and software. EMC said it would start by marketing Invista to larger enterprise settings.

Network-attached storage provides yet another course for virtualization. "There is starting to be a market for NAS virtualization," said Dan Smith, an enterprise consultant at GTSI. He said global namespace technology lies at the heart of NAS virtualization. Global namespace presents multiple file storage devices as a unified pool of storage in much the same way that SAN virtualization pools block-level storage.

Network Appliance, for example, uses NuView's StorageX data management software, which includes global namespace capability. NetApp has rebranded StorageX as Virtual File Manager for use in its products.

"Virtualization has gotten a lot broader," Smith said.

— John Moore

Resiliency: Virtualization's other benefit

The ability to withstand a knock or two is perhaps one of virtualization's unsung benefits, and government customers find that the attribute comes in handy. Features such as failover and disaster recovery help customers deal with device failure and electrical problems.

The storage-area network in Ogden, Utah, lost an array for a week, but users felt no impact. That's because LeftHand Networks' SAN/iQ software groups storage arrays in clusters and provides for automated failover should an array go down.

The failed array was one of four in Ogden's virtual cluster, and the transition to the working units went undetected. Administrators weren't even aware of the problem until they were inspecting equipment and noticed the lights weren't blinking on one of the storage modules. Normally, the system sends an e-mail message to administrators in the event of a failure, but in this case, the message was blocked by a spam filter.

"Virtualization really allows for fault tolerance," said Jay Brummett, Ogden's chief technology officer. LeftHand's approach "allows for the reality that disk drives and arrays and switches and all of the components that make up a SAN will fail at some point."

The situation was more dramatic in Eagle County, Colo. Temperatures in the county's server room recently soared to 130 degrees after an air conditioning unit shut down. The room remained at that temperature for almost five hours before the problem was discovered. But once the room was cooled, all the storage in the county's LeftHand SAN came back online.

LeftHand's SAN/iQ software "shut the system down, protected the data and brought the whole thing back online," said John DeNardo, director of innovation and technology for Eagle County. The server sauna corrupted 16 Microsoft SQL Server databases, but administrators restored the databases from the disaster recovery site, he said.

Concerned that the high temperatures might have affected reliability, county officials have decided to replace all the storage devices. But the recovery demonstrates the SAN's ability to survive a disaster.

— John Moore


  • Workforce
    White House rainbow light shutterstock ID : 1130423963 By zhephotography

    White House rolls out DEIA strategy

    On Tuesday, the Biden administration issued agencies a roadmap to guide their efforts to develop strategic plans for diversity, equity, inclusion and accessibility (DEIA), as required under a as required under a June executive order.

  • Defense
    software (whiteMocca/

    Why DOD is so bad at buying software

    The Defense Department wants to acquire emerging technology faster and more efficiently. But will its latest attempts to streamline its processes be enough?

Stay Connected