Yesterday, today and tomorrow

It was 20 years ago today when Fortune Magazine noted that off-site computer data storage was booming. Even then the concept of DR as evinced by storing tape backups in a location far, far away from your primary location wasn’t new, the magazine noted that this kind of service had been around from the early 1950s. So you see, DR isn’t new, it started long ago.

For a business, a disaster is the end of the world as far as it is concerned. An inadequate DR infrastructure can lead to shutters slamming down and RIP being carved on a business’ gravestone before you can say 3DR, CDP or any of the acronyms that the study of DR compels one to get familiar with. Some of these technologies help a business on an everyday basis, not only when disaster strikes. For instance, using disk instead of tape for first-level backups can slash the backup window and improve productivity by bringing a production system online in minutes instead of hours. This could be done by using virtual tape libraries that emulate a tape library while writing data to inexpensive SATA disks. Which is not to say that tape’s outmoded. Far from it, it’s now the final frontier, the last line in the DR front. Hence the need for 3DR where a SAN array writes data to a nearline or VTL box, which is backed up to another disk box in a remote location and from there it’s away to tape for the worst case scenario backup.

CDP or continuous data protection in tandem with WAFS or wide-area file services can be an unbeatable albeit expensive answer to instant recovery. These solutions mirror and synchronise data across locations over a WAN and keep your business systems accessible even if your primary site takes a hit. To keep the amount of data flowing down those WAN links at a reasonable level, companies can use techniques such as data segregation (decide what’s important and what’s not; e.g. your ERP database is critical, presentations are probably not), deduplication (backup only one copy of a large e-mail that went out to the whole marketing department) and delta differential synch transfers (only send those blocks or files that have changed since the last backup). Then there’s the question of equipment. Traditionally you’d need your secondary site to mirror the configuration of your primary. Thanks to virtualisation that’s no longer true.

So where is DR technology headed? Some trends are clear. Replication speeds are on the rise, costs are waning and it’s just a matter of time before grid technology gets co-opted for DR in many-to-many topologies. Virtualisation is having a profound impact on every sphere of IT be it servers, desktops or storage and DR is no exception to that rule. Tomorrow, DR will be a given. Smaller organisations will most probably outsource it to third-party data centres and larger ones will give it no more thought than any other fundamental part of their IT architecture.

Prashant L Rao
Head of Editorial Operations