At the low end of DLT technology is the ValuTape80 from Benchmark Storage Innovations. This slim drive uses the DLT Tape IV, a common older DLT format media with a 40-GB native and 80-GB compressed capacity, and can read tapes written by Quantum's DLT4000 series tape drives. The ValuTape80 and the DLT1 drive, both from Benchmark, are targeted to customers with large installations of DLT4000 drives with DLT Tape IV media. DLT4000 drives have a native capacity of 20 GB and a compressed capacity of 40 GB, so the Benchmark drives offer double data capacity with the same tape.
LTO
LTO, aka Ultrium, tape products represent a shot over Quantum's bow by a consortium of vendors unwilling to jump on the DLT/SDLT bandwagon. With HP, IBM and Seagate as backers, LTO offers a broader manufacturing base for the tape buyer. The first generation of this tape technology, Ultrium Generation 1, has a native capacity of 100 GB of storage and a compressed capacity of 200 GB. LTO has a four-generation road map that includes single cartridge sizes up to 1.6 TB compressed with a transfer capacity of 320 MBps. The current Generation 1 LTO has a transfer rate of 40 MBps compressed and 20 MBps uncompressed.
LTO has gained acceptance in the market because the idea of a consortium-based tape technology appeals to many, and the technology has been integrated into the designs of most automation companies. The smaller LTO format has a slight advantage over DLT in speed, but not in capacity.
A big selling point for LTO is read/write compatibility. There were reports of incompatibility among HP, IBM and Seagate drives, but those were early production bugs, not a long-term issue. There also have been some differences between the vendors' products, such as buffer sizes and minor mechanical differences, but the promise of LTO from a portability standpoint has been fulfilled.
LTO has seen strong growth but must continue to be marketed aggressively to gain significant market share. Sony and Quantum will not rest on their laurels, and the LTO consortium has been slower to introduce the second generation of LTO than we would like.
AIT-3
Sony's Advanced Intelligent Tape 3, or AIT-3, is written on 8-mm tape, as opposed to the 1/2-inch tape used by LTO and DLT/SDLT, and is in its third generation. The first generation of AIT, AIT-1, has 35-GB native and 90-GB compressed capacity with transfer rates of 4 MBps, or 10 MBps compressed.
Note that Sony touts a 2.6:1 compression ratio for its AIT drives, as opposed to the 2:1 compression ratio for every other tape format out there. Sony attributes this increased compression to its ALDC (Adaptive Lossless Data Compression) technology. While we don't doubt that ALDC can provide improvements, compression ratios can be drastically affected by the nature of the data being backed up. For example, feeding precompressed data to the tape drive can reduce compression ratios considerably.
The second drive in Sony's AIT stable is the AIT-2, which is read-and-write compatible with AIT-1. This second-generation drive has a native capacity of 50 GB and a compressed capacity of 130 GB, with transfer rates of 6 MBps, 15 MBps compressed.
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FYI
According to the University of California at Berkeley's How Much Information project, "The world's total yearly production of print, film, optical, and magnetic content would require roughly 1.5 billion GB of storage. This is the equivalent of 250 MB per person for each man, woman and child on earth." Find more on the data explosion at "How Much Information?"
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The current generation of AIT is AIT-3, with a native capacity of 100 GB and 260 GB compressed. Transfer rates are 12 MBps native and 30 MBps compressed. One of the nice things about the current AIT format is its backward compatibility: In addition to AIT-3 tapes, you can read and write AIT-1 and AIT-2 tapes on an AIT-3 drive. This makes for a smooth upgrade path.
VXA and Mammoth
In August 2001, Exabyte, manufacturer of Mammoth technology, and Ecrix Corp., maker of VXA drives, merged. The resulting company, called Exabyte, sells both Mammoth, on the high end, and VXA systems on the low end. As separate companies, the two were struggling. Ecrix, in particular, was having a difficult time marketing its VXA technology. The resulting merger brought marketing savvy for VXA and engineering expertise for Mammoth.
The latest generation of Mammoth drives is the M2, which offers 60 GB of native capacity, 120 GB compressed, and transfer rates of 12 MBps native and 24 MBps compressed. The VXA-2, has a native capacity of 80 GB, 160 GB compressed, and transfer rates of 6 MBps native, 12 MBps compressed.
Both technologies have fallen behind AIT, DLT/ SDLT and LTO. The VXA line, according to Exabyte's technology road map, is targeted at companies with lower data capacity and transfer rate needs. The Mammoth line will be aimed at the forefront of tape technology, with a Mammoth-3 drive that the company claims will outperform competitors due next year. But Exabyte had better roll out these M3 drives early next year, as opposed to mid- or end of year, if it doesn't want to get lapped by its rivals.
Associate technology editor Steven J. Schuchart Jr. covers storage and servers for Network Computing. Previously he worked as a network architect for a general retail firm, a PC and electronics technician, a computer retail store manager, and a freelance disc jockey. Write to him at sschuchart@nwc.com.
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