The fundamental benefit of true continuous data protection (CDP) is the preservation of revenue-generating, or revenue-enabling, business applications. The promise of CDP is the instant availability of business applications despite any failure, for local or remote recovery. For years, tape backup was considered the only means of data protection and recovery. In and of itself, tape backup is a relatively reliable and affordable data protection method. Tape media is durable and can be easily stored in a climate-controlled environment for long-term protection.
However, as data volumes have grown and dependence on data availability and fast recovery has increased, the limitations of tape media have become all too apparent.
For starters, data recovery from tape is time-consuming and imprecise. Recovery points can exceed 24 hours, and restoring an application to full operation can take even longer. This makes it difficult for companies to meet Recovery Point Objectives (RPOs) and service-level agreements (SLAs).
When tapes are stored off-site, as is often the case, it can take several days to retrieve the tapes and restore data. The revenue and productivity lost during that period can be devastating to a business.
Most tape backup implementations use backup agents on application host servers to back up data from servers. These agents consume application host processing time, which becomes problematic (especially when virtual server technology is used). In some cases, server backup can impact the server itself-enough to affect application performance. Furthermore, the explosive growth of data has expanded server backup requirements to the point where the backup window has diminished, and completing backups on time has become nearly impossible.