Backup gets a boost: Hot Spots

Snapshots, continuous data protection and deduplication are making their way into traditional backup products. By capturing, transferring and storing less data in the backup process, organizations can back up more data to disk--retaining data on disk for longer periods of time or enabling disk-to-disk backup for more sets of data than before.

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Backup vendors benefit from snapshot and dedupe technologies. You can, too.

Three new technologies--snapshot, continuous data protection (CDP) and deduplication--are making their way into traditional backup products at a time when the market is demanding more efficient, less-costly solutions.

There are several drivers for this optimization. First, unabated data growth continues to stress backup infrastructures. Capacity requirements for secondary storage are burdening backup and disaster recovery (DR) budgets. The time needed to perform backup operations is simply unworkable for many organizations, even when disk-to-disk strategies are applied. Key business apps such as corporate messaging systems and ecommerce portals require uninterrupted access. And performing a reliable backup may mean taking active systems offline. As a result, minimizing downtime and the amount of data lost in a recovery event (recovery point objective or RPO) are at the top of many organizations' to-do lists.

Backup vendors have made some strides in moving advanced technologies into the mainstream. For example, snapshot and CDP technologies are being integrated with backup platforms. Similarly, data deduplication, deployed in target storage systems, is becoming an embedded feature in backup applications. These developments have increased the backup vendors' value proposition and may even call into question the need for supplementary vendors' technologies in many cases.

Snapshot software, as its name suggests, represents an image of the data as it appeared at the time the copy was initiated and creates a usable copy of it. The interval between snapshots determines the level of granularity for restore; the smaller the interval, the fewer changes to the data.

Snapshots address a few of the primary challenges mentioned earlier, including backup window, recovery time objective (RTO) and RPO. By creating a snapshot copy of the data, a file-level backup to disk or tape can be accomplished outside of the backup window, minimizing the impact on the production environment. This is the concept behind VMware Consolidated Backup (VCB) in server virtualization environments and Volume Shadow Copy Service (VSS) in Microsoft Windows environments. Snapshots also enable the capture of open files in active systems, such as messaging systems, databases and running virtual machines.

Snapshots offer the advantage of providing the first level of recovery: rapid restore for aggressive RTOs. They also provide an encapsulation of data. When combined with offsite replication, DR requirements are addressed. RPOs can stretch from one minute to several minutes or one hour to several hours, depending on the capture interval selected. When data needs to be restored, the snapshot for the desired point in time is located and recovered.

Users may leverage this approach as a wholesale replacement for file-level backup or as an additional layer of protection. Because most backup vendors offer some built-in support for snapshot, either approach is feasible. Integration with the backup policy engine and interface simplifies management. Improvements, such as incremental snapshot, data deduplication and the ability to directly recover an individual item from a snapshot backup, make this approach more practical.

Research from the Enterprise Strategy Group (ESG) has found that snapshots are the most widely implemented advanced technology for backup, with 51% of survey respondents--small- and medium-sized businesses (SMBs), as well as enterprise organizations--employing snapshot solutions. Twenty-six percent of all respondents have plans to deploy this technology in the next 12 months to 24 months, with varying degrees of urgency in the SMB and enterprise camps.


Continuous data protection
CDP is similar to snapshot technology in that it maintains a record of data at a specific point in time. The difference is that it continuously captures changes to data--resulting in unlimited restore points--which in turn results in near-zero data loss and greater granularity in recovery. When recovery is needed, any previous consistency point can be selected.

CDP technology isn't new, but its integration with backup platforms is a more current development. A few backup vendors have embedded policy options for snapshots at specific intervals, providing built-in, near-CDP functionality. However, other vendors have gone a step further and enabled centralized control and integration between former standalone "true" CDP solutions and the backup platform.

The technology addresses many of the aforementioned optimization challenges, including aggressive RPOs and RTOs, and improved reliability of active system backup. The one drawback is that CDP may consume more storage capacity than snapshots. CDP delivered via the backup platform also provides the advantage of protecting heterogeneous storage devices, topologies, platforms and applications.

ESG research examined the adoption of CDP and found that 53% of respondents will deploy or plan to deploy the technology within 24 months. Two of the primary reasons cited for not using CDP are the cost of a new solution and no perceived need for the technology. Other reasons include not being familiar with the technology and a lack of skills for implementing and managing CDP.


An increasing reliance on disk and the rising volume of data to be protected are two developments that make data deduplication so enticing. The economics of applying disk in the backup process further improve with deduplication. The technology's ability to eliminate redundancy in secondary storage processes optimizes network and storage resources.

By capturing, transferring and storing less data in the backup process, organizations can back up more data to disk--retaining data on disk for longer periods of time or enabling disk-to-disk backup for more sets of data than before. Reducing data capacity also aids in better network bandwidth utilization.

For remote offices and branch offices (ROBOs), reducing or eliminating the reliance on a tape backup infrastructure in favor of disk can introduce cost savings mainly around tape media handling. Deduplicating data aids in the transfer of data between ROBOs and the data center and/or increases local storage capacity. In the data center, the impetus may be enabling recovery from disk vs. tape to meet RTOs, or replicating data to a remote location to facilitate a disk-based DR strategy. And then there are the challenges created in server virtualization environments, as server virtualization increases the amount of data and files that would normally be kept on a single physical server. Backing up virtual hard disk images may impact network traffic, the backup window and storage capacity.

Early adopters have implemented deduplication more often in target storage systems--including disk-to-disk appliances and virtual tape libraries (VTLs)--mainly due to the ease of implementing the technology in existing backup environments. However, several backup applications now include data deduplication as a feature. Source-side deduplication in the backup application's client agent and/or media server offers a few advantages over target-side deduplication, including a reduction in LAN, WAN or SAN traffic, as well as distribution of the deduplication workload across multiple nodes in the backup environment.

The data protection market continues to evolve with new products and features enabling more optimized backup and recovery. This progress means some vendors could be left behind, as evidenced by the tape-based to disk-based backup transformation in most organizations.

Most recently, leading backup vendors have acquired or developed advanced technologies and more tightly integrated them into existing backup platforms. The integration of snapshot, CDP and deduplication is amplifying the value proposition set forth by backup vendors and calling into question the need for standalone technologies. For example, the inclusion of data deduplication as a feature in popular backup products is a competitive threat to deduplication vendors. However, this should translate to improved backup options for your IT shop.

This was last published in August 2008

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