CDP: Confusion delays proliferation

Our Special Report this month (see “Making sense of CDP,” p. 24) explores continuous data protection, which is actually a very good phrase to describe a backup/recovery technology that continuously records data changes and enables uses to “roll back” to any point in time for very granular recovery-sort of like TiVo. However, there are hard-core definitions of CDP (“true CDP”) and looser definitions (“near CDP”), and then there are the vendors that jump on the buzzword bandwagon and totally twist the term to suit their technology.

As a result, there would appear to be dozens of vendors in the CDP space when in fact there are only about one dozen that qualify under the strictest definition. Nevertheless, the definition issue may confuse end users, and confusion leads to lack of adoption.

Further muddying the waters, CDP products can range anywhere from $1,000 per server to more than $100,000 per appliance. The price disparity relates, in part, to whether the product is file- or block-based, true or near CDP, etc.

In a survey of InfoStor’s readers last year, 15% said they were already using CDP, and another 19% planned to deploy it this year. Given the relatively low shipment figures for true CDP products, it’s clear that our readers are using the looser definitions of the technology. But it’s also interesting to note that 37% of the survey respondents have no plans for CDP-however you define it-and 11% admitted to not knowing what it is.

Basically, whether you need a recovery-focused technology such as CDP comes down to your recovery point objective (RPO) and your budget.

If you have data recovery issues and need more information on your options, be sure to also read “The changing face of data protection,” p. 30, which follows our Special Report on CDP.

CDP is a variation on the disk-to-disk (D2D) backup/recovery theme, and there’s no doubt that D2D is taking the IT industry by storm. In fact, results from an end-user survey conducted by Peripheral Concepts and Coughlin Associates indicate that by year-end there will be more data backed up on disk than on tape. (For more information on the 2006 Tape vs. Disks for Secondary Storage report, visit www.periconcepts.com or www.tomcoughlin.com.)

Until then, however, tape remains the workhorse in the majority of backup operations. For a look at your expanding options for tape-based backup and/or archiving, see “Focus On: Midrange tape trends,” p. 16.

And any discussion of D2D- and/or tape-based backup isn’t complete without an examination of tape virtualization. However, as with CDP, definition issues may cloud the picture. For example, there are three roads to tape virtualization: virtual tape, virtual tape libraries (VTLs), and tape library virtualization. That’s an issue that analyst David Hill tackles in “Tape virtualization has many faces,” p. 38.

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Dave Simpson

This article was originally published on April 01, 2006