Intelligent ATA arrives to meet backup and recovery SLAs

Computer Technology Review,  Sept, 2004  by Stephen Terlizzi

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All organizations, regardless of size, are concerned with data protection. Yet few have adequate backup and restore processes in place to ensure they can (1) protect their data, maintain business operations and user productivity, (2) accommodate exploding data growth, and (3) ensure compliance with emerging government regulations (e.g. Sarbanes-Oxley).

IT managers have turned up the heat on storage administrators, requiring their strict adherence to service level agreements (SLAs) that are impossible to meet. Evolving SLAs dictate shorter backup windows to reduce departmental downtime, while government regulations dictate fast and ongoing access to more and more data. Unfortunately, though, many organizations report failure when it comes to successful backup and recovery. In fact, confidence in the backup and recovery process is currently the lowest of any activity in the data center.

How can organizations ensure adequate data protection and regulatory compliance in our highly volatile world? Through a combination of new and evolving storage technologies, as well as careful consideration about where and when to deploy those technologies, IT managers can give their organizations the tools they need to guarantee success in this critical data center activity.

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First, organizations must develop a formal backup and restore policy that:

* Balances the need to backup all of the data as frequently as possible, against the cost of the solution and the outage time required

* Ensures that a history of backups are securely sent offsite in the event of an onsite disaster

* Creates a methodology to periodically test all archived backup media for reliability and ensures data integrity on that media for complete and full data recovery

There is a variety of emerging backup and restore technologies that can help storage administrators successfully execute against their policies. Emerging disk-based backup solutions can significantly reduce backup and restore times, while giving organizations regular and fast access to data. In addition, they can be augmented with a smaller tape infrastructure for offsite data rotation and archiving.

Backup Technology Considerations

The two key elements of backup and restore are the recovery time objective (RTO) (i.e., how quickly the data must be restored) and the recovery point objective (RPO) (i.e., how current the data must be once it is restored). There are some applications (e.g., stock transactions and other online transaction processing functions) where recovery time is as little as one hour and each transaction must be current. This, therefore, requires that each and every I/O be backed up in a synchronous manner. For such applications, monolithic Fibre Channel solutions with disk-based replication features are currently the only way to go. However, for the majority of backup and recovery environments, monolithic Fibre Channel disk arrays are overkill.

On the reverse end of the cost equation, until now low-cost tape had been an attractive alternative to more costly disk-based solutions. While tape still has its place in the data center, companies are under increased pressure to ensure regular and fast access to data in order to comply with new governmental regulations. If a company finds itself under scrutiny by the SEC, it will be given a limited amount of time to produce required data. Sifting through thousands of tapes may not be feasible. Moreover, the unreliability of tape means there are no guarantees that the data required would actually be there.

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In a survey of 500 IT departments completed in January, Meta Group found that as many as 20% of routine, nightly backups fail to capture all data. Compounding the problem, the only way to verify that data has actually been successfully captured on tape is by manually reading the data on the tape. Tape management complexity and reliability issues mean that over-reliance on this storage media could spell disaster for many organizations ("Concerns Raised on Tape Backup Methods", Keith Regan, www.searchsecurity.com, 4-15-04).

Intelligent ATA: An Exciting New Option in Disk-Based Backup

Fortunately, users have another backup and restore technology option in the form of low-cost Serial ATA disks. However, not all Serial ATA solutions are created equal. In fact, many customers who have deployed Serial ATA solutions report that backup and recovery time remains a key issue. Many only deliver around 50-70 MB/sec of performance, equivalent to only 2-3 LTO2 tape drives. Certainly, these solutions reduce management complexity and make it easier to verify successful backup, but nothing has been done to close the growing gap between shrinking backup windows and growing amounts of data.

Traditional SATA architectures aren't delivering the performance needed to handle the 30-plus days of data that 55% of users want to keep on disk-based backups (The Evolution of Enterprise Data Protection: User Adoption of Next-Generation Backup and Recovery Technologies, Enterprise Storage Group, December 2003). Moreover, they are challenged in their ability to read a backup while writing an archive to tape. Even modular array solutions, whether built using Fibre Channel or Serial ATA drives, will suffer performance degradation because they are limited in the number of FC loops that can be supported for storage.