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P-Guide Continuous Data Protection, A Closer Look.pdf (86.13 KB)

Executive Summary
A sound data protection strategy is more important than ever. Unfortunately, many of the typical solutions are not as effective as advertised. In the last few years, however, an innovative new type of backup approach-commonly referred to as Continuous Data Protection (CDP)-has been providing IT administrators with a range of flexible new data protection options.

Introduction
Is our data-protection approach effective?
That question is on the minds of plenty of IT professionals these days, and it's not hard to see why. Given the critical nature of company data, even small periods of downtime can kill productivity and lead to serious bottom-line consequences. At the same time, today's regulatory environment demands compliance to a dizzying range of standards, everything from HIPAA and Sarbanes-Oxley to the Fair Credit Reporting Act, the Gramm-Leach-Bliley Act, and others. And then you have the ever-present threat of nature's fury-since 2003, the U.S. Federal Emergency Management Agency notes that there have been more than 300 natural disasters in the United States alone. If that's not disturbing enough, Gartner Group research reveals that more than 90 percent of companies that experience a major loss of data will be out of business within five years.

In short, a comprehensive data-protection strategy is an absolute necessity. Given that, companies have begun using a relatively new set of metrics-Recovery Time Objective (RTO) and Recovery Point Objective (RPO)-to gauge the effectiveness of their efforts. RTO is the maximum length of downtime for a system or network after a disaster or technical failure. RPO, on the other hand, can be defined as the maximum acceptable amount of data loss as a result of a disruption. The challenge for IT staffs:

1) find the most efficient (and cost-effective) way to make the RTO to as close to zero as possible

2) keep the RPO as small as possible.

In other words, protect and recover your company's data quickly, effectively, and cheaply.

The Trouble with Typical Solutions
The problem, of course, is that it's long been extremely difficult to accomplish that aim. As for solutions, they typically boil down to two options: 1) disaster recovery/business continuity planning and 2) regular, tape-based data backups. Unfortunately, neither of those always work as well as advertised. Consider disaster recovery/business continuity plans. They're difficult and unwieldy to test, so there's no way to completely ensure they'll function properly. Management also can have unrealistic expectations about them and often doesn't fully understand what IT is capable of delivering. And the plans can be expensive to implement-perhaps one reason why a 2008 AT&T study revealed that nearly 30 percent of U.S. businesses don't see business continuity planning as a priority.

While daily tape backups do provide security, they're not without their own issues. For starters, they slow production, gobble up system resources and bandwidth, and can have up to a 24-hour lag between each backup. Plus there's always the human error element-witness the case of the University of Utah Hospital and Clinics system, which recently lost backup tapes containing the billing records of more than 2 million of its patients when they were stolen from a courier's car.

CDP: The New Answer?
Managing all of this is difficult enough for IT managers at larger enterprises who have a wealth of resources and sophisticated backup strategies at their disposal. But what about their counterparts at mid-sized businesses who must contend with tighter budgets, limited staff resources, multiple office locations, and remote users?

In the last few years, an answer has emerged in the form of a new generation of disk-based backup technologies. Generally lumped together under the term "Continuous Data Protection" (CDP), these systems allow for faster backups and nearly instantaneous data recovery.

CDP Defined
There are numerous CDP definitions floating around. The Storage Network Industry Association (SNIA) defines it as a "a methodology that continuously captures or tracks data modifications and stores changes independent of the primary data, enabling recovery points from any point in the past." IDC has defined it like this: "Continuous data protection, also referred to as continuous backup, pertains to products that track and save data to disk so that information can be recovered from any point in time, even minutes ago."

In other words, CDP protects and captures data as it is written to disk and automatically saves every change made to any item of data on a company's system. By doing so, it can restore data to its condition before a loss or interruption-and often in a matter of minutes or even seconds. The result: less data loss, less business downtime, and an effective to find a balance between RTO and RPO.

Pure CDP vs. Near-CDP
One key distinction to keep in mind: the difference between "pure CDP" and "near-CDP." Pure CDP systems provide infinite point-in-time recovery options, while near-CDP systems allow users to restore data to specific points in time through the creation of data snapshots.

How Does CDP Work?
In part, the answer depends on the product and vendor. There are some fundamental differences in system types, however. The block-based approach is perhaps the most common. It works by capturing blocks of data as they are created and then storing them to an independent location. In contrast, file-based CDP solutions record file-system changes-creation of new files and modification or deletion of older ones, etc. Another type, application-based CDP, works from within a specific application and can be designed as part of the application itself.

CDP vs. RAID
Finally, don't confuse CDP with RAID (redundant array of independent disks). RAID does provide some protection by redundantly storing the same data on multiple disk drives. But RAID drives are typically housed together, which leaves them exposed to potential disasters. In contrast, CDP solutions save data to a remote drive that provides additional protection.

CDP Solutions
While they have been generally more expensive than tape-based technologies, CDP systems have come down in price in recent years. CDP usage also appears to be growing, at least among larger firms. A December 2007 survey by InfoStor magazine of enterprises with at least $1 billion in revenue revealed that 17 percent of the companies are now using CDP. What's more, another 29 percent are planning to deploy it. Recent IDC research backs up those figures. According to the firm, the disk-based data protection sector will grow from $8 billion in 2006 to more than $50 billion by 2010.

As that growth has geared up, vendors have been responding by adding new levels of functionality to their products. Here's a look at a few of them.

CA XOsoft WANSyncHA Product Suite
CA XOsoft's WANSyncHA Product Suite is a stand-alone pure CDP solution that uses asynchronous real-time replication to provide disaster recovery capabilities for Microsoft Exchange, Microsoft SQL Server, Oracle, Microsoft IIS Web servers, file servers, and other applications on 32- and 64-bit Windows.

The WANSyncHA Product Suite uses either LAN or WAN connections to replicate and synchronize files, databases, and entire applications. It also maintains functional backups of complete database and application servers. The servers can be local to the organization, but they can also be maintained remotely, with real-time replication carried out over the WAN. One key feature is the suite's Centralized Manager function, which allows IT administrators to manage all replication/failover scenario configurations from a single console. Flexibility also factors into another useful feature: the CDP Repository, which features full text-searching capability and allows end users control to recover data quickly without placing the burden on IT staffers.

Price: The WANSyncHA Product Suite starts at $4,500.

Double-Take for Windows
Double Take Software's Double-Take for Windows is another stand-alone solution that's based on a fundamental CDP concept: It uses asynchronous replication to capture byte-level changes as they happen and replicates them to one or more alternate servers at any location around the world. It's also highly configurable and has no has no affinity to any hardware or storage provider or storage architecture.

One key element of the software is the Full-Server Failover feature, which allows IT administrators to set up, monitor, and failover entire production workloads between servers (and virtual machines) regardless of their hardware differences. The feature also protects the operating system, applications, and data, which eliminates the need to separately manage service packs, application updates, or hotfixes on the standby server. Final note: Double-Take for Windows is a near-CDP solution, but it can be made into a true CDP solution for an additional cost.

Price: Double-Take for Windows starts at $2,700.

EMC RecoverPoint
EMC's Recoverpoint is a SAN-based platform that provides asynchronous replication for near-CDP recovery capabilities. According to the company, the appliance, which is sold as part of a larger solution, can provide fast recovery to any point in time or failover to a remote site in case of disaster with a single set of management tools and a single user interface. The company also notes that it provides concurrent local and remote data protection technology, which offers the flexibility to replicate and protect data in many local and remote-site combinations with less storage footprint-whether for production applications or for test and development.

Price: EMC RecoverPoint start at $4,000.

Symantec Veritas Backup Exec 12
Symantec's Backup Exec 12 is a pure CDP offering with backup, open file protection, disaster recovery, and single-drive library support capabilities. Like EMC's RecoverPoint, it's sold as part of a larger solution. Unlike the other products discussed here, however, it provides both disk and tape-based data protection. Designed specifically for the Windows Small Business Server, Backup Exec features the company's patent-pending Granular Recovery Technology, which allows for the recovery of individual e-mails, folders, and mailboxes in seconds, without the need for separate mailbox backups. The result: IT administrators no longer need to run multiple backup jobs to protect Exchange, which helps reduce backup times.

Price: Veritas Backup Exec 12 starts at $3,500.

For more information on these solutions-and on CDP in general-contact Productive Corporation:

We Can Help You
Deployment Questions
Licensing and Technical Support
help@productivecorp.com
800.726.4099

About Productive Corporation
Productive Corporation is a specialized software reseller that helps small and medium businesses across North America with software initiatives in security, storage, and infrastructure. We provide subject matter expertise, access to technical resources, and excellent customer service. We also strive to provide the most relevant resources for our customers.

About the Author
Chris Mikko is a Twin Cities-based writer and editor who specializes in technology topics.