…especially as we continue to see the data growth scale higher and higher. Many of these replication solutions have been around for quite some time, but because of our general business requirements, we either didn’t require that level of availability, found it to be cost-prohibitive, or simply didn’t know it existed and worked as well as some of the proprietary hardware solutions. One of the products that has found success in the mid-tier level is NSI Software’s Double-Take.
It will replicate a set of data at the application level, before it reaches the cache. It has been around for quite some time, but has not gotten proper attention because general business requirements have not been sufficiently compelling to evaluate this as a solution. Now we are facing new challenges and new requirements that ask us to stage data in two or three different locations: source, electronic vault, and perhaps a third location for sanity purposes. Solutions like Double-Take allow you to stage the data in such a manner, allowing for more granularity in the replicated data sets. For instance, the first set of data to the staging server might only replicate a subset of that data to the next stage, and so on.
It is assumed that clients will target a remote protection server that will host replicas of their data. These replicas will be backed up to tape via normal scheduled backups. In this scenario, the protection server acts as a disk consolidation server and then performs optimized backups from this consolidated storage. This type of backup does not require a SAN, but the protection server storage certainly could justify SAN connectivity. The replica data on the protection server can be backed up using traditional backup methods or any of the supported frozen image backups.
An anticipated way to further leverage technologies and get even more benefits from real-time backup is to use injected markers in the replication stream to notify the remote target or protection server that the application has been quiesced and that it is safe to take a snapshot. This allows the creation of consistent point-in-time snapshots that can potentially be used for rollback and can be written to tape.
Many different scenarios based on the combination of these technologies are being investigated, and we are sure we will see many of them come to market in the not too distant future. The ability to create consistent versions of data to protect against corruption while allowing for disk-based rollback to a point in time is very attractive. Coupled with this is the ability to move data to tape for true data protection with minimal impact on production systems and applications-a very attractive feature.
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