Tape archiving is not dead yet

The emergence of disk archiving has seen end-users taking advantage of the storage choices on offer, writes James Ward

The demise of tape at the expense of disk for data archiving is something that has been predicted for some time. As the cost of disk has fallen, there has been a significant growth in the use of disk-based backup solutions.

Businesses across all sectors are switching to disk-based archiving. The cost per GB for disk has fallen below that of tape. Ten years ago, a terabyte of disk storage in a Raid array would have cost £150,000. By 2000, this figure had plummeted to £12,000, and today is far lower still. As a result, customers are much less reluctant to make the switch to disk.

This differential can only get bigger. Because disk is the major cost element within a Raid solution, the benefit of disk-based technologies has had a dramatic effect on the total solution cost because capacity has increased at the same time.

By contrast, with tape-based solutions the hardware is more costly than the media. As a result, the ability to cut the overall solution cost is restricted. Also, tape technology is struggling to keep pace with the increase in capacity that can be achieved by disk.

Yet in no way has this heralded the death of tape as an archive medium. So what is happening?

Tape continues to have an advantage: it is a uniquely removeable media, so it is perfectly suited to vaulting technologies, storage in safes and offsite or remote locations. The introduction of remote replication of disk now allows users to copy disk offsite, yet many users still prefer the control of knowing that critical data is still held on tape.

This is where vendor strategies have been instructive. Software vendors have increased their focus on disk-based backup. Similarly, tape vendors are releasing truly disk-based backup solutions or a combination of disk and tape. Such vendors would, of course, like the market to go the latter route, where disk is used as a staging post to ensure data is backed up quickly before being transferred to tape for archiving.

So the bottom line is that today’s end-user is simply taking full advantage of the greater flexibility and choice on offer. The increased functionality and improved backup techniques that disk offers means that, as a supply chain, we have more tools from which to choose in specifying the most efficient and cost-effective solution for each individual business. C

James Ward is managing director of Hammer.