Venyu Blog

Writing in the latest Storage Magazine (and repurposed here in SearchDataBackup.com),Lauren Whitehouse, an analyst focusing on backup and recovery software and replication solutions at Enterprise Strategy Group, (ESG) provides a primer on data backup technologies that help enterprise administrators to meet their backup recovery time objectives (RTOs) and also reduce the amount of data being backed up.

According to Whitehouse, in 2004 nearly 60% of ESG survey respondents backed up directly to tape, a total that by 2010 had fallen to just 20% of respondents who were using tape exclusively. In 2011 approximately 80% of IT organizations tell ESG they’re supplementing their backup processes with disk, which helps them meet backup windows and backup RTOs. As a result, ESG has identified the following technologies being implemented more frequently to aid and abet data backup for their organizations. These include:

Snapshot and image-level backup

A snapshot is a copy of a volume or file system created at a specific point in time. Taking advantage of snapshot functionality for backup can dramatically reduce the impact on apps by eliminating the backup window, providing backup RTOs of seconds to minutes and enabling better recovery point objectives (RPOs) by enabling more frequent copies per day. Image backup uses snapshot technology to create a point-in-time image of a system (such as hardware configuration, OS, applications and data), storing it in a single portable file. This approach eliminates the backup window and enables rapid whole-system recovery to any system (virtual or physical), including to dissimilar hardware. After the initial base copy is made, only incremental blocks are captured and stored.

Continuous Data Protection

CDP technology continuously captures changes to data at a file, block or application level, supporting very granular data capture and recovery options. It time stamps each write and mirrors it to a continuous data protection retention log. When a recovery is needed, the CDP engine creates an image of the volume for the point in time requested without disrupting the production application. Block-level CDP operates at the logical volume level and records every write. This type of continuous data protection stands out at transparent data capture and presentation of views at different points in time. Because it captures data as it’s created, that data is immediately recoverable. This allows CDP-based solutions to deliver near-zero RPOs.

Replication

Replication is the bedrock of these strategies and it’s increasingly being used for data protection as a standalone process to provide operational and disaster recovery for applications with tight RPOs or RTOs; as a method of consolidating distributed data for centralized file-level backup; or in conjunction with snapshot or CDP to maintain an off-site copy and facilitate disaster recovery. Replication provides an exact mirror copy of data on a local or remote primary system that can be mounted to rapidly recover from a failure. Replication is available on host systems, storage arrays or in network-based products.

Source-side deduplication

Deduplication identifies and eliminates redundancy, storing only unique data and shortcuts to unique data for duplicates. Data deduplication’s role in optimizing backup processes is fairly well documented; however, the focus has mostly been on target-side deduplication solutions. Source-side deduplication ensures that only changed segments are backed up after the initial full copy. That means significantly less data is captured, transferred and stored on disk. This reduces the time needed to perform backups. Because the backup window requirements are minimal, it’s possible to back up more frequently, which increases the number of recovery points on disk storage to meet RPO and RTO requirements.

As for how these various solutions “shake-out” in the real world, among survey respondents ESG research found a significant uptake in several of these technologies: while the use of snapshots grew only 2% between 2008 and 2010, replication use increased 34%, CDP expanded by 58% and deduplication use improved 66% in the same two-year period.

A wholesale replacement of file-level backup is likely for many organizations today, according to ESG research. For example, 55% of IT organizations surveyed by ESG plan to replace existing file-level backup with snapshot and/or CDP solutions. That said, the integration of snapshot, replication, CDP and deduplication into existing backup platforms to augment file-level approaches seems to be a strong trend. That’s why several backup vendors [Venyu included], have made recent strides to match capture techniques to recovery objective policies, simplifying implementations and optimizing the front end of backup processes.

Read about these and other data backup technologies available with Venyu’s RestartIT Recovery platform here.