Rumour has it that IBM Corp’s pseudo announcement about its automated tape library (CI No 2,604), the New Tape Product, should have been made the same day Hitachi Data Systems Ltd announced its Media Manager series of automated tape libraries (CI No 2,600) and Storage Technology Corp officially announced its helical scan-based Redwood and half inch tape-based Timberline automated libraries (CI No 2,597). But for some reason IBM cried off, and the theory is that it wanted to avoid making public technical details that have not yet been finalised. Apparently it is the logical volume management of small data sets that is the big challenge. And this technology is likely to be crucial to the attractiveness of NTP, or whatever it is to be called, and IBM needs NTP to be successful if it’s to gain ground on StorageTek’s strong position.
Widely used
Tape is still widely used for back-up and archiving, libraries especially so, and in this market StorageTek dominates. International Data Corp’s 1994 figures on shipments of tape drives for mainframe systems show that in a declining market StorageTek’s share rose 2% to 58.6% and IBM’s fell 2.6% to 24.2%; Hitachi Data Systems’ share was 9.4%, a rise from 6.7%. IBM believes NTP can reverse its decline and set a new standard for automated tape libraries. The optimism is based on a couple of factors, one of which is that although StorageTek ships more drives, IBM has a large installed customer base to which it can sell. The other factor is the capacity and management promised with NTP. The cartridges will be mechanically compatible with the robotic t ransports in IBM’s current 3490s but the medium will be metal particle and read by magneto-resistive heads. Uncompacted, each cartridge will hold 10Gb in 200 50Mb sectors, and there will be some kind of indexing for improved access speeds. IBM says there will be 10 cartridges to a magazine, boosting the capacity of an IBM 3494 to 30.4Tb. However, new compression formats are said to be able to boost capacity of each cartridge to 40Gb and this, coupled with the logical volume management, means that for some companies, all their data could be stored on just four drives. Logical volume management is the control of the sectors on the tape, and to take full advantage of it, IBM will bundle something called Tape Mount Technology, a software-controlled fi ltering system that traps tiny data sets in a disk buffer and transfers them to tape when there are enough of them to fill a tape. Storage Technology reckons this kind of functionality is best located in the applications, and warns that unless people configure the software correctly, small data sets could get written to large tapes. StorageTek, despite its dominance, is concerned about the NTP and says there’ll be no complacency when it comes to preserving its market share. The company had its first automated tape library in 1985, Hitachi in 1989 but IBM did not have an automated tape library until 1993, the 3495 Tape Library Dataserver, rather unkindly described as a tractor in a glass house. But it doesn’t appear to have sold very well. Sources suggest there are only a couple of dozen 3495 sites in Europe with the smaller capacity 3494, shipped in 1994, doing better. The 3490s were launched a decade after IBM launched its first cartridge drive, the 3480. By Maya Anaokar
When StorageTek was automating its libraries, IBM was ignoring what the customers wanted – automation – and, instead, pursuing data compression. Starting with a 200Mb tape, IBM introduced Improved Data Recording Capability which pushed capacity to 600Mb; next came 36-track technology and capacity rose to 1.2Gb; and then IBM doubled the tape’s length to create a 2.4Gb tape. But by then StorageTek’s automated library had effectively become the industry standard. And while IBM now admits that it was in error coming so late to market with an automated library, it says StorageTek’s products do nothing to help companies manage data or the number of tapes. If anything, it suggests StorageTek would rather peop
le did not manage data very well, so that they do need more and more tape. IBM, which is about to publish the results of a three-year survey into how people manage tape, says there’s a long-held belief that somehow it doesn’t matter how many tape silos you have because they are cheaper than disk. In this way companies have allowed tape proliferation without concomitant data management. StorageTek says companies are not really that slapdash about data, however, IBM and Hitachi are making money from selling tape management services. IBM, which has been working on NTP since 1991, believes NTP will set a new industry standard, but it won’t ship until after StorageTek’s Redwood ships. However, IBM reckons the two products are aimed at different markets, with the higher capacity, higher performance Redwood suited for scientifc settings while IBM says it’s going after commercial users – banks, insurance companies and the like. But this statement is at odds with shipment details. First to market will be NTP with Small Computer Systems Interface attachments, the usual scientific interface and the MVS versions will ship later as they have to wait for an Escon converter. Nevertheless, IBM claims NTP will be better than any linear product. The few details the company has released say the tape speed will be 79 inches per second.
Serpentine
StorageTek’s Timberline streams the tape at speeds of 158 inches per second and has a totally redesigned transport to ensure that the tape is not damaged. But IBM’s foray into double speed tapes, the 3420, put it off high speed; it says that at 200 inches per second, when the head stopped to read the tape, the force was the equivalent of a car hitting a brick wall at 30mph. Nor has IBM gone for helical scan technology, as StorageTek has with Redwood. New Tape Product uses a serpentine linear track format which it says will have lots more than 36 tracks, probably 144. IBM, however, did investigate helical scan technology along with Redwood City, California-based Ampex Inc (CI No 2,300). But the problem, says IBM, is that as a contact recording technology, it has higher potential for wear and tear on the tape and heads. StorageTek says it has minimised the problem: Redwood’s tapes can be read and written to up to 20,000 times, an enormous improvement over the current number of read-writes, which is in the low thousands. And it says the problem of wear is managed by the system itself, which changes tapes before damage occurs so that the user doesn’t have to worry about that. IBM’s official announcement on NTP is expected next quarter and systems will ship in the second half of the year. IBM plans to bundle applications like automated save-restore and migrate-recall; record management, multimedia applications and back-up software with its planned Redwood slayers.
