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The elimination of tape
Should you discard tape if you install a D2D solution? The answer in most cases is probably not yet, maybe never. Why? Because most organizations are so procedurally and emotionally attached to tape that it would be too drastic to eliminate it. Of course, the answer depends on what new backup solution is picked. In the case of an Avamar, for example, where data is radically reduced, you could replicate data over long distances and store huge amounts of data directly on disk. But in the case of Revivio, for instance, you probably would still want to back up from the appliance to tape, duplicate the tape and send one set offsite.
Until recently, replication technology has almost invariably been associated with business continuity and disaster recovery. Data is first protected on the local site using regular backup to tape and specific volumes that are considered critical are replicated to a remote site, using technology such as SRDF from EMC or IBM's Peer-to-Peer Remote Copy (PPRC). These tools typically replicate data between arrays on a synchronous basis--the local data is not written to disk until the remote site has signaled that it has received and written the data to its disk system. In more cost-sensitive environments, users deploy host-to-host products such as Veritas Volume Replicator (VVR) and NSI Software's DoubleTake. These work asynchronously and are independent of the underlying storage
Thus far, backup and replication technologies have been distinct from each other, but a new crop of products is blurring that distinction. Such products are being delivered by next generation replication-focused vendors like Kashya and Topio, or by virtualization software players such as StoreAge Networking Technologies and FalconStor Software and by virtualization appliance vendors such as Candera Inc., DataCore Software Corp. and Troika Networks. Using different methods, these products are able to significantly reduce the data that's transferred, so that consolidated remote backup becomes a feasible concept. Instead of doing a local backup--creating tapes for local and offsite storage and replicating the most important data--why not combine this functionality and just back up to a remote site, disk to disk and eliminate tapes altogether?
In particular, if a company has a large number of remote sites that have little or no IT presence, why not backup to a central site where IT personnel can apply common methods and policies across the enterprise? It's important for users to validate a vendor's ability to maintain data consistency across multiple data sources. The application of replication technology for backup consolidation purposes will create new avenues for inexpensive data protection for many businesses, particularly midsized companies.
A new era
A new era of data protection is fast approaching. As a result, most companies will revamp the way they have done backup, restore, replication and archiving within the next two years. Small storage companies that "don't know what can't be done" are creating the foundation for these innovative ways to protect data.
This was first published in April 2004