Recently, the Linear Tape-Open (LTO) Program technology provider companies, Hewlett-Packard (HP) Co., IBM Corp. and Quantum Corp., announced the addition of generations seven and eight to the Ultrium LTO product roadmap, with native capacities of 6.4 TB and 12.8 TB, respectively. The technology provider companies claim that the addition of a larger compression history buffer will increase compression to 2.5 to 1, allowing compressed capacities of 8 TB for LTO-6, 16 TB for LTO-7 and 32 TB for LTO-8.
However, while capacity doubles with each new generation, the data transfer rate does not as it had in earlier generations. According to the published Ultrium LTO roadmap, LTO-6 will offer a native data transfer rate of 210 MBps, up from LTO-5's 140 MBps. LTO-7 will offer a transfer rate of 315 Mbps and LTO-8 will run at 472 MBps.
Independent backup expert W. Curtis Preston likes this approach. "My only problem with tape is that it's too fast," he said. "When you slow down, you get shoeshining; you wear out your tapes, you wear out your drives, you get backup failures, etc. So, it's good they are aware of the issue and are doing their best to address it."
Bruce Master, senior program manager at IBM, said the decision to make smaller increases in data transfer rates was based on results of a survey of LTO tape media users conducted by the technology provider companies.
LTO tape media is being used more often for data archives
"If you look at what tape is being used for more and more -- infrequently accessed data -- it's really a capacity play," said Dave Russell, Gartner Research vice president, storage technologies and strategies. "I think this is a clear indicator that the market isn't clamoring for more speed as the market shifts to a different use case for tape."
Beginning with the current generation LTO-5, tapes offer users the ability to partition each tape into two segments, and the LTO's Linear Tape File System (LTFS) spec uses one partition to store a file system index of the data stored in the second partition. The file system allows users to drag and drop files to and from tape the way they do with disk. LTFS is open source, so any application provider can download the LTFS spec from the LTO Ultrium website.
"I think we'll see data archiving solution providers try to exploit this capability," said Russell.
Currently, LTFS has only been integrated with one product from a company outside of the LTO technology providers, the For-A LTR-100HS video archiver. However, Master said that there other vendors have expressed interest as well. He also noted that video is an area where they expect to see a lot of use of LTO tape. "With digital video, high def, 3D imaging and medical imaging, the amount of data is humongous," he said. "To store that on disk would be cost prohibitive."
Russell also noted that LTO tape has been used for offline video storage in the past, and that it is likely the LTO technology provider companies are looking to continue to make inroads in that area. "There's been a lot of buzz in the media about disk with things like Avatar and digital rendering, but if you aren't James Cameron, and you are a typical television or cable outlet, storing everything on disk is just too expensive," he said. "The demands are for more capacity and ease of use, which they've begun to address with LTFS, making tape easier to search."