Disk-Based Data Protection

By Tom Schmidt

The ongoing and explosive growth of data volumes inside today's enterprises has placed unprecedented strains on IT organizations. Their challenge, needless to say, is to provide necessary data protection in the face of ever-shrinking backup windows. Too often, however, IT organizations have neither the people nor the hardware to manage all that data.
 
As a result, enterprises are increasingly turning to disk-based backup as part of their overall disaster recovery plan. While this technology has been available for some time, only recently has it become genuinely practical. This article looks at some of the key benefits of disk-based backup, and how it can meet the data management challenges of today's IT organizations.

How disk-based backup has evolved

Disk-based backup involves using a hard drive, rather than another type of storage medium. A disk-based backup solution typically writes the same data to a file on a disk volume as it would write to a tape drive. Therefore, when a backup-to-disk operation is finished, a single file the size of the backup will exist on disk that contains all the backed-up files.

As mentioned, this technology has existed for some years, but a number of hurdles -- including cost and file and disk management issues -- kept it from being widely deployed. But today's disk-based backup solutions are proving to be more affordable and able to tackle file and disk management. File management has been added so administrators can set size limits and maximum numbers of files per backup job. Disk management has been addressed by letting the backup applications reserve disk space to prevent disk-full errors and even provide early warning when specific capacity thresholds are reached. In addition, the most effective disk backup solutions now support all rewritable and removable media, such as DVD-RW, CD-RW, Zip, and Jazz.
 
The result is that disk-based backup solutions can now bring improved backup and recovery speeds and new efficiencies to IT departments. The use of disk drives enables faster, more flexible backups and restores. Although tape has made significant improvements in throughput and capacity over the past few years, it is still very inflexible compared to disks.
 
Which is not to say that tape has no future in data protection. Thanks to a combination of technical advances and recent regulatory initiatives, tape as a medium for backup and archival storage continues to attract attention. For example, the Sarbanes-Oxley Act requires organizations to have necessary controls in place to ensure the integrity of their information. Plus, many enterprises have invested significant time and money in their tape solutions, and they are unlikely to throw those investments away overnight. The bottom line is that tape remains the best medium for long-term and offsite storage. Its portability and ruggedness make tape the most efficient way to protect a business from disaster or for long-term storage.

That said, there is no denying that ongoing advances in disk-based backup technology have made it a viable, cost-effective alternative to traditional backup media. Disk-based backup lets IT organizations get more out of their current backup windows. It brings the benefits of faster backup and restores, high performance with multistreaming, greater control of data, and reduced intervention on the part of IT administrators. Given today's ever-shrinking backup windows, those are profound advances.
 
What sort of adoption rates are we talking about for disk-based backup? In a recent survey conducted by InfoStor, 64% of respondents indicated that they planned to purchase disk-based backup products this year, and 42% of respondents said that they plan to purchase disk-based backup products instead of tape to enhance their existing data protection plans.

Adding up the benefits

Putting it bluntly, traditional data protection has been overwhelmed by explosive data growth and burgeoning data recovery requirements. Today's enterprises demand a scalable backup and recovery solution to reliably and rapidly restore business-critical data. Thanks to advances in disk-based backup technology, enterprises can transcend the limitations of traditional backup and recovery practices to take advantage of the following benefits:

• Speed In most cases, backing up to and restoring from disk is faster than using tape. Also, because disks are random-access devices, the drives can instantly start to transfer files, whereas tape drives require that the tape be loaded, accessed, and sequentially written.
• Flexibility The faster, more efficient storage capabilities of disk drives let administrators schedule more frequent backups, lowering the exposure from any data loss. Disks used as backup devices can also support simultaneous backups, restores, and duplication operations. This is impossible with sequential tape drives.
• Efficiency Disk-based backup's ability to write multiple backup jobs simultaneously to individual backup files (one file per job) provides both exceptional performance and storage granularity that tape solutions cannot approach even with the most sophisticated multiplexing, multi-threaded solutions.
• Expense Because disk-based backup increases the speed, flexibility, and efficiency of a data protection strategy, it also lowers the total cost of ownership of storage management.

Conclusion

IT organizations need to improve backup performance and simplify recoveries. For today's enterprises, that means continuous data protection

Tom Schmidt writes frequently about information security topics. He has more than 15 years' experience as a writer and editor in high-tech publishing.