Filling the storage gap: nearline innovations extend scope of existing enterprise storage capabilities. (SAN).

Enterprise storage is no longer relegated to back-office IT departments. Paralleling the rise of "business continuance" as a common topic at the boardroom level, the importance of strategically managing an organization's critical data is an emerging concern for companies focused on smart growth in an economy that demands doing more with less.

In today's information-intensive economy minutes of downtime can equate to millions of dollars of lost revenue. Disasters and interruptions to business operations do occur, and enterprises require a plan to recover their IT systems whether the problem is a corrupted file or the catastrophic loss of a data center.

A comprehensive approach to enterprise storage requires a continuum of solutions with various levels of availability, recovery speed and cost. But that's where IT specialists and executive boards alike run into a problem. There's a huge gap, in terms of both performance and cost, between highly available, online disk-based storage and the low-cost backup functionality of tape.

Compounding the matter is the rapid growth of storage that, even with a slowed economy, is doubling roughly every five to 10 months. New applications featuring rich data types such as CRM data, digital image medical records, and geographic exploration data stored by oil and gas companies are also burdening existing storage architectures that rely solely on traditional disk-to-tape technology.

Finally, the emergence of the realtime enterprise, where managers, customers and companies with a mobile sales force need instant access to a comprehensive data set, is bringing the storage gap to the forefront. With corporations focused on staying competitive while watching capital expenditures, getting the most out of their existing technology investment is a critical business imperative.

Increasingly, organizations are turning to new hardware and software solutions--known as nearline storage--to mitigate the risks associated with downtime while enabling enterprises to realize higher availability and greater returns on storage investments.

The Emergence of Nearline Storage 

In today's data-intensive business climate, organizations need continuous access to mission-critical information. IT departments must not only manage the rapid growth of business information, but also keep this information available and protected.

Storage experts suggest the art of building a successful enterprise storage infrastructure lies in assessing the risks and achieving the right level of resilience without gravely impacting the bottom line. Nearline storage fills an important role between online disk-based storage and offline tape.

Online storage is best suited to applications that require constant, instantaneous access to data, such as databases and frequently accessed user data. This information is business critical in a call center, where the rapid ability to call up a record may be the only difference between a satisfied customer and a lost sale.

At the other end of the spectrum is offline storage such as tape, which is used primarily for applications where infrequent serial access is required, such as backup for long-term storage.

Between online and offline storage, falls a range of new nearline storage technologies such as Network Appliance NearStore R100; a network-attached storage appliance that spans a range of nearline-based applications, including backup and recovery, reference data, online archival, and remote disaster recovery. Such nearline storage solutions are for applications that require quicker random access of data compared with offline storage, but do not require the continuous, instantaneous access provided by online storage.

NearStore solutions are designed from the ground up for data protection and business continuance while enabling organizations to replicate more data at a more economical cost than ever before. Utilizing less expensive ATA disk drives instead of high-performance SCSI or Fibre Channel drives (hence the name nearline instead of online), these highly scalable appliances offer capacity at a lower price--roughly 2 cents per megabyte. ATA-based disk drives receive data faster than tape drives and can shorten an overextended backup window--a common problem that creates time sinks for IT staff in handling backup and recovery demands.

Nearline technologies are not intended as a tape replacement but as an intermediate step to accommodate increasingly complex storage demands. In fact, since a nearline device such as NearStore supports the most popular tape backup software, it acts as a repository of tape data for nearline recovery. Backing up to a nearline storage solution and then to tape enhances data protection management and improves primary storage and tape library performance. It's also faster and consumes less application-server CPU than direct backup to tape.

Backing Up the Three Is

Increasingly globalized and sophisticated, today's enterprises are demanding storage systems that provide bulletproof backup capabilities, near-instant restore functionality, and constant access and availability. Nearline systems complement primary storage solutions by streamlining backups to tape and enabling near-instantaneous data recovery.

With their ability to scale up to 100Th, large-capacity nearline solutions also help storage administrators consolidate management of multiple recovery and backup applications onto far fewer systems, reducing precious administration time and allowing IT departments to focus energies elsewhere.

But nearline storage is perhaps at its best as a foundation for so-called resilient systems, which are ushering in a new era of storage architecture that relies on three critical components--redundancy, remoteness, and recoverability--to provide organizations with broader storage functionality.

Redundant versions of data prevent downtime and curb data loss. If an original data file is corrupted or destroyed, a secondary copy is available to keep information flowing. Nearline storage is well suited to storing redundant copies of data because of its large capacity, network connectivity, and interoperability with popular backup and replication software packages. For example, NetApp NearStore is compatible with Veritas Netbackup, Legato NetWorker and RepliStor, CA BrightStor Enterprise Backup, and Connected TLM, as well as NetApp's new SnapVault software for online backup. It can connect to multiple primary storage platforms, including NetApp and third-party vendors, over an IP network and become a central repository for redundant data.

Remoteness extends the concept of redundancy by backing up data at locations removed from immediate catastrophes. Nearline appliances can be located remotely and connected to primary storage via IP network connections, which are commonly used for metro-based and wide-area networks (WANs). Utilizing mirroring software, products such as NearStore are a cost-effective destination for the replication of data across wide area networks. By employing incremental block transfers to reduce bandwidth consumption, NearStore makes remote system backup over almost any WAN practical.

Recoverability--the time it takes to recover from an interruption--is a third important element. On the sliding scale of storage cost/functionality, the more immediate the recovery, the more expensive it is to enable. For example, a real-time mirror can provide nearly instantaneous failover capabilities, but requires expensive redundant production systems. Conversely, tape backup is far less expensive, but requires hours or days to restore, especially if the backup process is manual. Nearline storage enables organizations to bridge this gap with less expense and greater functionality.

Archival and Reference Data: Storing the Future

Archival solutions are another key growth area for the nearline storage market, which, according to Strategic Research Corporation, will reach $5 billion by 2005. Archives are normally used for auditing, analysis, and retrieval of infrequently accessed data as opposed to mission-critical application recovery.

Once files are archived they are normally deleted from the primary storage system and not available online for fast retrieval. Today's data archival solutions using nearline storage eliminate the manual, labor-intensive process of archiving to tape by providing accelerated access to archived data while allowing the automation of data archiving based on policies and seamless retrieval.

However, this traditional form of archiving is changing as disk-based nearline storage proves well suited to online archives of large or infrequently accessed information. Known as reference information this rich data--everything from medical and check images to CAD/CAM and integrated circuit designs--is increasingly considered to be of such high value to an organization that it is retained online for active access.

Typically, this information has been stored on expensive primary storage or lower performing HSM-based systems. Software-enhanced integrated nearline technology can immediately revert a file system back to a previous point in time to allow instantaneous recovery. Doctors, for instance, can call up data-rich medical information such as a CAT scan or MRI on a patient for near real-time diagnosis rather than wait for the records department to retrieve a file.

The extensive new functionality afforded by nearline storage provides a vital missing link for organizations demanding more from their existing storage architecture. In fact, 45 percent of respondents in a 2002 survey by online magazine Byte and Switch said their organization was considering adopting disk-based backup in the next 12 months. With less expensive nearline options such as the Network Appliance NearStore solution hitting the market, a hurdle they listed--the cost--is no longer an impediment. Nearline storage is here to stay.

RELATED ARTICLE: 11 Considerations when purchasing a nearline storage solution

1. Is the product shipping today, and who is using the product?

2. Is it flexible, and does, it support numerous applications?

3. Does it enable fast backup and recovery?

4. Is it open, and will it support your infrastructure?

5. Is it robust (highly available, reliable, are there tools to measure availability, self-healing, self-diagnosis, legacy of software developments)?

6. Are there certified key application partners?

7. Is it simple to administer?

8. Is it cost efficient?

9. Does it support a high capacity of data?

10. Does it scale with zero downtime?

11. Does it enable you to replicate your data to a remote destination?

Michael Marchi is senior director of enterprise marketing for at Network Appliances (Sunnyvale, Calif.)

www.netapp.com