Tape Is Dead ? No, Not Really...

In recent years, we have seen a shift away from tape media as a means of protecting corporate data. Tape has a long history of being the media of choice, due to it's ability to pack data in high density, low cost, portable packages. But it is also sensitive to magnetic interference, and temperature extremes. But the paradigm remains. How does an IT organization protect it's valuable data in an offsite, secure way, without incurring unreasonable costs ?

Many companies, like HP, believe that tape is dead. In fact, they have a product-line called SEPATON - "no tapes" spelled backwards. They believe that the cost of near line storage - inexpensive secondary data arrays - has come down far enough in price to challenge tape as a low-cost medium. In some respects, it is true.

Others would argue that the near line array needs to be offsite in order to satisfy even the most basic Business Continuity schemes. So the pat response is to house the secondary array in a second data centre ! Well, doesn't that fly in the face of keeping the data on the cheapest media possible ? Imagine the face of the CFO when you suggest you want to DOUBLE his costs for IT !

A recent "replacement" for traditional tape systems is the Virtual Tape Library (VTL). VTL takes common storage devices line SAN or NAS, and mimics a Tape Library. The data is streamed to "tapes", which in reality are small disk volumes on the storage device. I've never really seen the value of having a VTL, as you lose the portability.

In all reality, current ideas about Information Lifecycle Management (ILM) point towards a tiered storage approach. Data being used by business applications in day-to-day operations is stored on a Primary, high-speed array. When data is considered stale, either due to it's age (a few days for example) or a change in it's IO requirements, it can move to a secondary tier of storage, in less expensive and lower performance disks. Finally, data which has not been accessed in a longer period of time (say 6 months) gets relegated to long-term retention - AKA tape.

This ILM means that data can be moved around automatically, according to pre-defined policies, in line with the business's goals & requirements. Further, tape is still used for long-term data retention, but is not the primary means of recovery. The secondary tier provides the majority of that function, minimizing the tape requirements, but not eliminating it.

The opinions expressed in this post are purely those of the author. Opinions are like noses; everyone has one and they are entitled to it !