When Microsoft announced System Center Data Protection Manager (DPM) earlier this year, a relevant comment that stuck in my mind was Microsoft's claim that DPM was what its customers were asking for and that the continuous data protection (CDP) model that the rest of the storage industry was touting--continuous backup of critical data instead of the "x-number-of-times-per-day" model that DPM supports--wasn't what customers wanted or needed.

Only time will tell whose approach is the correct one, as market forces will determine which data-protection methodology is most successful. But last week, yet another major storage vendor jumped on the CDP side of the fence: EMC announced its EMC RecoverPoint CDP software.

RecoverPoint is an application-aware CDP scheme that uses dedicated storage to maintain a full baseline copy of protected data and to store continuous updates to that data, capturing every write made to the data it's protecting. This means that an administrator can recover the protected storage to any point in time, not just to the last time that a scheduled backup was run or the last snapshot of the changed data was taken, as might be the case with a more limited data-protection scheme. Application awareness means, for example, that you can recover a set of databases even if they reside on multiple-array systems. Of course, the backup protection will have aggregated that data to its dedicated storage.

To address the problem of determining when data corruption might have occurred, EMC has coined the term "significant point-in-time" in reference to actions that applications might take that are good places to set a consistent recovery point. These significant points can be policy based--such as a regular hourly checkpoint, the daily data rollup for your databases, or the point at which the financial day or month ends--or application based, such as after a database rollback or roll-forward. This significant point-in-time model runs concurrently with any other point-in-time protection already offered by EMC's CDP software; it just provides an additional means for recovering corrupted data. If an administrator is aware of the precise point at which data became damaged, the administrator can restore data to the point just prior to the damage regardless of any significant points he or she might also be using.

RecoverPoint isn't a standalone software product; it requires a supported version of EMC Replication Manager to be installed on each host for which you want to provide the RecoverPoint CDP protection, because RecoverPoint uses Replication Manager's agent technology. Although this requirement will limit initial adoption of RecoverPoint to businesses that have already standardized on EMC's data-replication technology, it also becomes a strong selling point for the overall EMC data-storage solution.

The real-time CDP market continues to attract major players--a condition that exists because customers and vendors are acknowledging the value of restoring critical data from any point in time. The growing acceptance of the need for CDP begs the question of whether CDP technology will continue to be a differentiator between data-protection solutions or whether customers will make it a check-box item for their data-protection needs. At the moment, CDP vendors are still educating the market about their solutions' value; in a few years the technology will likely be an expected one in any complete data-protection solution