Hail, Hail, tape is dead! The wicked tape is dead! Just as Dorothy was dreaming, so are you if you think tape no longer has its place within the data center. Predictions that tape would die a slow death and give way to cheap disk and robust storage array features are still far from reality. Personally, the perceived move to disk was just way too sexy to resist as everyone liked the look and feel of disk. But tape still lingers and there are good reasons for keeping tape around as part of your overall data protection strategy. Consider the following:
- Data Growth. Just as change is the only thing constant in this world, explosive data growth will continue. IDC recently announced in a white paper, entitled “The Diverse and Exploding Digital Universe: An Updated Forecast of Worldwide Information Growth Through 2011,” that the digital universe is bigger and growing more rapidly than originally estimated. The research stated that at the current annual growth rate of 60 percent, the digital universe is projected to grow to 1.8 zettabytes by 2011. (That’s right, zettabytes.)
The question becomes how much data do we keep and how much do we need readily available? Marcellus Tabor, Manager of Data Protection at Yahoo, worries in a recent SearchDataBackup article about where all his data will end up. He says, “We need LTO-6 right now, in a big way.” Notice he didn’t say he needed disk drive technology, he said TAPE!
- Cost Savings. Simply put, tape is less expensive than disk for long-term storage. In a recent Reuters article, “Clipper Group Reports Substantial Cost Advantages of Using Tape in Tiered Storage,” the company reported that over a five-year period the total cost of ownership of disk-to-disk-to-tape vs. disk-to-disk-to-disk resulted in a 23 percent savings when tape was deployed as the end solution for archival. In times when IT dollars are hard to come by, this kind of savings is too appealing to resist.
No one, however, is negating the importance of disk in a backup solution, but there is a balance that points in the direction of using tape to provide additional cost savings. Of particular interest, the Clipper Group study pointed to the fact that a disk-only solution is not a replacement for tape when cost is involved. According to Dave Reine, Director of Enterprise Systems for The Clipper Group, disk should be used to complement tape. He concluded by saying, “Our findings show that there are substantial potential savings when using tape in tiered approaches, and even when you factor in deduplication, tape-based strategies still provide an estimated 5:1 cost advantage over deduped disk in archiving.”
- Long-Term Archival. It is true that companies are changing the way they perform backups. More and more are implementing disk-to-disk. But as economies continue to change and government regulations force companies to keep more and more data available long-term, backup of data is going to continue to grow out of control. This long-term storage requirement will, as mentioned in the Clipper Group study, solidify tape’s roll in data protection. Will tape be the backup medium of choice? Probably not for short-term backups. But for long-term archival, where real-time access is not needed, tape may become the archival medium of choice.
- Green Storage. The Clipper Group study also reported that energy costs for disk were up to 290 times that of tape. Let’s face it, once data is on tape, that tape consumes zero power and generates zero heat. I don’t know how much more economical you can get. Granted, you may need to load the tape in the future, but for long-term archival data that is infrequently or never accessed, that it is unlikely.
- Virus and Data Corruption. A danger no one likes to talk about is the risks associated with keeping data accessible and available on disk, which makes it susceptible to viruses and data corruption. We are all aware that a worm or virus can quickly propagate between systems and infect every disk within an organization, if unprotected. Disk-to-disk backups and recoveries sometimes only aid in the spreading of a virus. Tape archives, on the other hand, can provide a different form of protection against viruses since they have little chance of spreading them. Even if a virus does make its way onto tape, it is impossible for that virus to corrupt other data sets on that tape or spread within the tape library.
The use of tape as a primary target for backup has changed over the years. The onslaught of low-cost, disk-to-disk based backup solutions coupled with the many problems associated with using tape as a primary target has rightfully enticed many data centers not to use tape in that capacity. But that does not mean there is no requirement to use tape within the data center, as the aforementioned five reasons point out. Further, there is still innovation in tape occurring at vendors like Overland Storage, which is continuing to move the ball forward in both disk and tape technologies.