Storage on demand

Tired of overbuying, overconfiguring or overallocating storage? Utility storage--used in a similiar fashion as electricity or water in your home--may be the answer to your prayers.

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Benefits of the utility model
Implementing a utility storage environment can reap many operational rewards. The following list of benefits comes from a report, "Shining the Light on Utility Computing--A Business Perspective," authored by Michael Fisch and published in The Clipper Group Explorer:

Delivers IT as a service, not as a box or fixed asset
Provides the enterprise with the right services, in the right amounts, at the right time
Optimizes the reliability, performance and total cost of ownership of IT resources
Responds quickly to support changing business requirements
Raises accountability for responsible consumption and reliable service delivery

Source: The Clipper Group Inc.
Flip a switch and get more or less storage, and only pay for what you actually use. That's the picture the term "utility storage" conjures--the idea that IT resources can be turned on and off to coincide with fluctuating needs just as we control the flow of electricity, water or gas into our homes and offices.

The benefits are as obvious as they are tempting: no more overbuying, overconfiguring or overallocating. As Jim Geis, director of system solutions and services at Forsythe Technology, a Skokie, IL, technology consulting firm puts it: A storage utility is simply "storage that is easily provisioned, reallocated, flexible and retrievable for any platform at any time for any purpose."

For Earl Patkowski, managing consultant in Bell Canada's infrastructure and operations group, the benefits of utility storage are real: "We only pay for what we really need," says Patkowski.

Defining terms
Put the hype aside and there are some very practical notions underlying the concept of utility storage, and some real products and services that are available now. Of course, it all depends on how utility computing is defined. There are three basic models of utility storage (other widely used monikers include: "capacity on demand," "pay per use" and "pay as you go"). They are:

  1. On demand. Vendors install storage systems configured with more capacity than is needed; users "turn on" additional capacity as required and are billed for the additional usage.
  2. Internal utility. In this scenario, an IT department pools its storage resources and adds the components necessary to internally administer the storage as an on-demand service to the company's business units.
  3. Off site. Storage service providers (SSPs) provide off-site storage facilities, typically based on a lease arrangement with SLAs that guarantee QoS. Many companies use SSPs for off-site backup; increasingly, SSPs are also being used to replace or augment onsite data storage.
Further clouding the meaning of utility computing is that it's an umbrella expression that refers to the entire computing environment, including servers, network and storage. However, a utility storage system can be implemented without also pooling servers and network components. For many companies, creating a storage utility may be the most logical first step toward implementing a utility computing environment. "Storage is probably the most easily interchangeable part of utility computing," says Forsythe's Geis.

Today, the technologies exist to virtualize servers and storage independently, says Eric Stouffer, program director for on-demand solutions at IBM Tivoli. IBM advises some of its customers "to implement one or the other first ... not try to tackle the whole thing all at once," Stouffer says.

Special sauce
"Business users have become extremely frustrated by the cost of storage services," says David Scott, CEO of 3PAR, Fremont, CA. He points out that improving disk usage can reduce capital expenditures, while using automation to eliminate administrative tasks will further cut storage expenses. Meeting service level expectations and commitments is also vital to the success of a storage utility environment, says Scott.

Being able to adjust service levels is a key concern for Epsilon, a marketing services provider based in Wakefield, MA. The company is moving toward a utility storage model to deal with frequent storage capacity fluctuations based on project requirements. "Our business changes all the time," says technical director John Gaythorpe. "People want a terabyte here, a terabyte there and tomorrow they don't want it."

The meanings of utility storage and the motivations for pursuing it may vary, but there is consensus on the key--or most desirable--characteristics that contribute to a utility environment. They are:

  • Common management tools
  • Virtualization
  • Policy-based allocation
  • Automated provisioning
  • Modularity
  • Scalability
  • Data availability and mobility
Because of interoperability issues, legacy storage gear and a basic mistrust of automated provisioning, most current utility storage solutions don't address all of the above elements. Today, many storage products offer volume management, virtualization and policy-based automated provisioning, but that's a far cry from the flip-the-storage-switch model.

However, some companies are starting to gingerly test the utility computing waters. Those pioneers will typically take a staged approach to creating their storage utilities. Each of the storage utility functions is likely to be implemented incrementally, perhaps on a project basis or as an upgrade to a current storage configuration.

On-demand storage: dollars and sense
Most of the larger storage vendors offer pay-per-use storage options, including EMC Corp., Hewlett-Packard Co. (HP) and IBM Corp. In all cases, the pay-per-use plans are based on traditional leasing arrangements, but each company offers a twist or two to distinguish their service. Most plans include a buyout option at the end of the lease period.
EMC's OpenScale on-demand storage requires an entry level capacity of 50TB. EMC works with the user to estimate expected capacity growth; the base capacity is added to the future capacity requirements to determine the "concurrent usage" for the basic monthly billing. Unusual demands are considered "swing capacity" and are billed only when that capacity is used. Customers can also add software to the mix--for business continuity or performance optimization, for example--as part of the monthly payment.
IBM Big Blue offers a variety of programs and can tailor them to fit specific needs. IBM works with the customer to determine a baseline capacity--or "band"--which also factors in growth over a three-year period. The band usage includes a plus/minus 10% buffer and is billed on a gigabyte-per-month basis. Usage above the band is called "burst" and incurs an additional charge for the time that the additional storage is used.
HP As part of its Adaptive Enterprise program, HP's pay-per-use storage plan is based on a three-year lease. Base monthly payments are figured on 65% of the lease value for the total amount of installed capacity--which is the initial capacity plus incremental growth over the three-year period. In addition to the base payment, customers pay for actual use on a monthly basis (metered daily use averaged over the month).

Pay per use
Today, the most popular utility storage models are the on-demand or pay-per-use offerings from major storage vendors such as EMC Corp., IBM Corp. and Hewlett-Packard Co. (HP). (See "On-demand storage: dollars and sense.") The vendors consult with users to determine their current storage needs and apply trending analyses to reasonably predict storage growth. They also try to identify any peak periods where storage that is above and beyond normal requirements might be needed.

After determining current and anticipated storage requirements and identifying any capacity needs above those levels, the on-demand vendors install enough capacity to cover all of those circumstances. The storage is installed at the customer's site and is fully controlled by the customer--which means that until the user decides to increase capacity, they only pay for the base level.

The financial arrangements for pay per use are modified lease agreements, with terms that spell out the costs for base usage and how charges apply to other levels of usage. There are some differences in how vendors bill for storage above the base level. For example, pricing for HP's on-demand packages for its StorageWorks XP and EVA storage array families is based on 65% of three-year lease plus usage, which is figured on average use over a month. EMC slices its on-demand storage pricing into three tiers: base usage, expected growth and peak periods. All vendors offer a buyout option at the end of the lease term.

For Bell Canada, the Toronto-based telecommunications firm, opting for a modified on-demand storage plan provided by IBM to handle its 28TB of storage wasn't a difficult decision. Consultant Patkowski says their experience with on demand for their servers and mainframes since 1996 made the transition on the storage side relatively easy.

Working with IBM, Bell Canada determines their requirements periodically. "We just give them a forecast of what we'll require," says Patkowski. And when more capacity is needed, "within 48 hours the [disk] space is attached to the servers--this way we can grow into the space as opposed to buying a large storage box and divvying it up." IBM's on-demand program has worked well for Bell Canada, allowing the company to cut its storage costs by 30% in the first year--which translates to about $1 million in savings. The future looks promising, too, as the contract includes price-performance improvements that could further pare costs by about 20% per year (based on reduced hardware and support costs).

Chuck Hollis, EMC's vice president of markets and products, says that the typical on-demand user works in a medium-sized company because larger companies have ample storage management experience and "already have storage forecasting and provisioning capabilities in place." Smaller companies, on the other hand, tend to have far less dynamic storage needs, so they may gain little economic benefit--if any--from an on-demand solution.

HP has been in the on-demand business since 1999 when it first offered its Instant Capacity On Demand program for servers. With that program, users would buy a four-way server, for example, but HP would install an eight-way unit. Customers could then turn on the additional processors as needed and then be billed appropriately. "That's been a hugely successful program for us," says HP's Nick van der Zweep, director of virtualization and utility computing, "and we've extended that to storage as well." In 2000, HP introduced a pay-per-use option--as an alternative to the outright purchase required in the on-demand plan.

Sometimes HP's pay-per-use storage model runs against the grain to customers' internal purchasing procedures. "What you get with usage-based pricing, and even capacity on demand, is the ability for the system administrator to activate and deactivate capacity--thus committing that company to expenditures," says van der Zweep. This can upset the normal purchasing authorization process and cause some concern within purchasing departments. HP addressed this issue by improving its storage management system with password and hierarchical authorities.

HP added "security so that only the right people at the customer site can turn things on and off," notes van der Zweep, and provided access to more information, such as a portal where customers can monitor the metering system that keeps daily track of actual usage.

All of the pay-per-use storage vendors say they are committed to their programs and that customer interest is growing. EMC's Hollis says the company's young program has been "somewhat successful," adding about 10 customers each quarter to their current roster of approximately 50 users. Companies that show interest in the program tend to "have enough capacity, but never really developed the capacity planning and forecasting discipline," says HP's van der Zweep.

IBM has seen similar success with pay per use and is planning for its evolution. IBM's Stouffer says the company is looking at how to better integrate applications into the utility storage picture. IBM sees Web services technologies as a key to integration that will "allow customers and application developers to describe the business process in essentially a programming-like language." Applications would directly address the storage infrastructure and "carry along their attributes of service-level objectives, business priorities and even process flows."

Despite the apparent popularity of pay-per-use storage, consultant Geis maintains a somewhat contrarian perspective, saying that if capacity and resource planning is such a management challenge "you have a bigger issue than having resources on-demand."

Storage meets Web services
Data Center Markup Language (DCML) is a new standard that its proponents say will comprehensively describe data center environments to allow the depth of interoperability required for utility computing. The DCML Organization (www.dcml.org)--spearheaded by EDS, Opsware and Computer Associates--is at the core of the effort to develop this standard; at last count, 44 other IT technology companies were also participating members of the organization.

According to the DCML Organization, DCML--based on XML, the lingua franca of Web services--will provide a method of not only describing data center components, but will also describe dependencies among the components and operational policies that control the functionality of those components and configurations.

Documents published by the organization admit that the spec will overlap the Common Information Model (CIM) standard. But the DCML Organization claims DCML will exceed CIM because it describes management policies of data center elements--something the group says is essential in order to use automation tools to create a utility environment.

IBM sees DCML's potential as a key factor for creating a "service-oriented architecture" to fully realize a computing utility. IBM's Eric Stouffer says that some of the Web services technologies and architectures that allow applications to communicate with each other "need to trickle down to the core technology providers." This will allow applications to directly address storage and other infrastructure components to define specific needs including "service level objectives and business priorities--and even process flows."

The DCML Organization is expected to release a first draft of the spec by mid-year.

Inside jobs
Creating an internal utility storage environment presents a different set of requirements--most notably dealing with currently installed systems. Many storage hardware and software vendors tout utility products, but just how much they help enable a true utility environment will depend on how they're implemented and how well they integrate with what's already installed.

For example, 3PAR's InServ Storage Server--while not designed to "utilitize" heterogeneous or legacy environments--includes some innovative technology that the company says goes beyond the pay-per-use model. Thin provisioning, a technology that offers a new approach to capacity allocation, is at the heart of 3PAR's modular storage system. Rather than doling out disk space to an application in sizeable chunks, thin provisioning allows an application to think it has as much capacity as it needs, but actually only allocates disk space to the application when it writes data.

Savvis Communications, a St. Louis, MO, IT computing and services provider, recently decided on 3PAR systems to supply off-site storage to its customers on a utility basis. Rob McCormick, Savvis' chairman and CEO, says the keys to utility storage are high availability, real-time provisioning and attractive pricing.

McCormick says the 3PAR system allows Savvis "to differentiate the SLAs for the different types of storage in an inventive way." Thin provisioning effectively lets Savvis oversubscribe its storage services and then meet actual demands as needed.

While 3PAR's solution allows users to set up their own utility storage environments, many shops don't have the luxury of installing new arrays. But many other vendors provide some of the building blocks of utility storage--individually, these products might not provide a full utility environment, but they can help meet some utility storage criteria using currently installed equipment.

Some companies have fashioned a utility-like storage environment by developing internal storage management processes that allow them to be responsive to new requirements, while avoiding overbuying and overallocating. BlueCross BlueShield (BCBS) of Tennessee uses a quarterly storage procurement cycle to avoid having to make large-scale storage purchases. "We get a lot more free support and attention than if we told them that we're set for the next year," notes Bob Venable, manager of enterprise systems. He says they considered pay per use, but rejected the idea: "You pay a premium for flexibility."

When BCBS buys new storage, it goes into a pool from where it's eventually allocated; some older disks are kept in reserve to handle unforeseen peaks or emergencies. By using a short procurement cycle, Venable says, "We always have enough for current needs, and we're always working on the next purchase."

Epsilon's need to quickly allocate storage on a project basis led them to test utility storage at the switch level with two Sandial Shadow 14000 switches. Technical director Gaythorpe says the Shadow's ConnectIQ software, which dynamically allocates network bandwidth and allows policy-based service levels, has brought Epsilon closer to an on-demand environment. "We're using it just like a utility--it makes it so easy to just remove [or] add storage at will."

Practical matters
Whatever route a company takes on the way to a utility storage environment, the success of the effort is likely to hinge on how effectively the business groups using IT services are integrated into the process.

One of the basic precepts of the utility model is providing timely and appropriately scaled services based on business needs--and to be able to adjust nimbly as those needs evolve. Toward that end, storage managers will have to build close relationships with business units--and the lines of business will have to adjust, too.

"What you're trying to provide with the utility concept is for internal IT departments to begin to show their worth to the business units that they provide services for," says Veritas Corp.'s Bob Maness, senior director of product marketing. Veritas recently announced two additions--Storage 4.0 and Availability 4.0--to its CommandCentral storage utility suite along with an upgrade to its CommandCentral Service component. With these enhancements, users will be able to better monitor and control resource allocation and usage, administer service levels and charge back costs.

Instituting a chargeback system is another important piece of the utility puzzle. Chargebacks are an effective way for business units to determine the specific levels of service their applications require while encouraging active involvement in the process. Storage managers can use chargeback data--even if the departments are not actually billed--to measure how well storage utility services are being delivered and help educate the business units on the cost of the storage they use.

Utility storage also can serve as the foundation for more advanced and cost-effective storage management processes, such as ILM and regulatory compliance. "You'll never get to enterprise-wide ILM or DLM without something approaching utility storage underneath," says Stephanie Balaouras, a senior analyst at the Yankee Group. "You'll only have a medley of point solutions."

This was first published in June 2004

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