The 1TB Barrier : Does Tape Have What it Takes?
Several factors have triggered the growth in enterprise storage needs, most notably the Internet. The meteoric growth of multimedia enriched Web pages, e-commerce transactions, and the Web's vast and ever changing storehouse of documents account for a large part of the anticipated 500 percent growth in enterprise storage needs over the next few years. Thus, it stands to reason that the future of enterprise storage must not only have to include improved capacity, but also a significant increase in data rate, reliability, capacity of off-line storage technologies such as tape. But do we really need 1 TB tape cartridges? The answer, it would seem, is yes.
Data storage has become central to the information technology infrastructure
According to Bruce Masters, IBM's senior program manager of worldwide tape product marketing, as customers' data needs continue to grow by leaps and bounds, the data will need to be secured in more cost effective manners. Large capacity tape, AKA 1 TB, can help to provide a number of user benefits by helping to minimize floor space consumption, reduce the number of tape mounts, and reduce library slot consumption helping to achieve attractive user operation cost targets."
Saurin Shah, director of advanced technology and applications at media manufacturer Imation, believes that the need for 1 TB tape cartridges really comes from two perspectives. "From an application perspective, companies that have a need to store images and audio require higher capacity storage," he says. For example: Shah points out that movies for HD television need 2 TB of space to be stored uncompressed. "This is one of the factors driving the need for higher storage capacity because this data is not compressible," he continued. (Note: this type of data is essentially pre-compressed and cannot be compressed again without altering the integrity of the data). From the other standpoint - data center products - Shah says the answer is simple. The needs of traditional IT storage have changed and the only way to keep up with these changes is to increase storage capacity and transfer rates.
"The questions that customers ask about storing their data are as varied as the requirements of their applications, says Shah. "How fast can I access my data? How much can I store in a single device? What is the cost per megabyte and the total cost of managing my data? How secure is my data? How portable is my data?" Shah says that for a broad set of applications, the answer is removable data ranging from floppy disks, CDs to DVDs storing from a few megabytes to a few gigabytes, through network tape libraries storing from a dozen to a hundred gigabytes on each cartridge, to enterprise data center storage applications that rely on high-speed, high-capacity tape cartridges storing hundreds of gigabytes on each cartridge to manage and safeguard terabytes of critical business data.
The development of 1TB tape technology
There have been a lot of technical and competitive developments in the tape storage industry in 2002. Quantum announced Super DLT 320 - Imation and O-Mass announced an initiative to develop a new tape format, Sony plans to roll out SAIT later this year, and tape technology has come to the forefront following the events of September 11, 2002 as it relates to disaster recovery. Perhaps most significantly, back in April, IBM demonstrated writing 1TB of data to tape. "I think this is a remarkable achievement that helps position IBM as a leader in tape development," says Masters. According to Masters, The 1 TB tape cartridge is part of IBM's enterprise tape roadmap that is planned to have interim products beginning at 200 GB capacities leading to the 1 TB technology in a few years. And, Shah says that tape systems as a whole are on a solid path of density growth, with capacity to deliver a 1 TB tape cartridge before 2008.
How will the 1 TB tape technology affect the storage industry?
According to Masters, tape is an important part of users' storage hierarchy because it is removable, portable, and can provide infinite capacity. "It's removable/portable characteristics helps protect it from accidental and intentional destruction," he said. "In addition, large capacity tape can help keep the financial aspect of tape attractive as compared to disk alternatives." Shah feels that it is difficult to say how the 1 TB tape technology will affect the storage industry. "The most effective 1 TB tape cartridge will have to keep the same transfer rate as the 100 GB tape which is 15 megabytes per second, and the only published roadmap is from Sony which states that the transfer rate for its 1 TB tape is about 60 megabytes per second," he says. "The key to the success of the 1 TB tape cartridge is the transfer rate and right now it is longer than people are willing to tolerate," he continued. "But, keep in mind that the industry as a whole is always working on increasing capacity and transfer rates, and everyone is working on achieving a high transfer rate," he says.
Are there disadvantages of a 1 TB tape cartridge?
Masters seems to think some users may be concerned that having that much data on a single tape cartridge puts it at an increased risk. "It behooves the tape mechanism provider to integrate data integrity and reliability technology to help protect access to the data," says Masters. "In addition some users may choose to implement tape mirroring strategies for critical data," he continued. Shah says that at the present time, the major disadvantage is the transfer rate. "We have acknowledged that the transfer rate has to be high and clearly this is something that we all have to work on," he says. Masters says that the 1 TB tape cartridges will need to transfer data at speeds that allow the user to fill the tape in a 2-4 hour window. "That figure is approximately 8 to 10 times the speed of super tape drives today," says Masters. The 2-4 hour window is a key factor as it often all the time that is available for backup.
How much more data are these 1-TB tape cartridges capable of storing?
One of the biggest issues surrounding the 1 TB tape cartridge is exactly how much more data do these tapes hold as compared to the linear tape cartridges currently available, and do we really need that kind of capacity in a single unit? Consider that Generation 1 LTO, which has been available since 2000, has an uncompressed capacity of 100 GB. The 1 TB tape cartridge would be 10 times that amount. Still with all of these numbers, it's hard to conceptualize exactly how much data these 1 TB tapes are capable of storing. So, to put it in more simple terms - a 1 TB tape cartridge can hold as much data as 694, 444 floppy disks. Or if you like, it would equal 2 weeks, 2-days, 19-hours, and 12-minutes of continuous DVD movies. Interesting though thse figures are, the more relevant applications to enterprise storage users is that the 1 TB tape cartridge will obviously reduce the number of tape cartridges presently required to backup large multi-terabyte databases. Just how much of a reduction depends on what tape format standard is currently being used.
Will tape, as a storage medium, continue to be viable?
Shah says the industry is still very focused on the full capacity of tape as a storage medium. "Backup, restoring, and archiving - we see all of these applications of tape as having an advantage over other technologies in terms of cost and efficiency," says Shah. "Over the years, tape as a storage medium has gone down in price and maintained cost advantage and transfer rate," he concluded. General research bears this out. Although tape drives themselves are expensive, the media is relatively cheap considering it's portable and durable nature.
Masters concurs. "Tape is an important part of a user's storage strategy because since tape can be removed from the system at comparatively low costs, it can help provide high levels of disaster tolerance and business continuance."
In our continual drive for more capacity, it seems that by the time the 1 TB tape comes around, the industry will be more than ready for it. In the meantime, we'll just have to settle for the 300+GB capacity offered by today's tape drives.