UDC 681.327.634 Information Storage for the Broadband Network Era - Fujitsu’s Challenge in Hard Disk Drive Technology - VYoshimasa Miura (Manuscript received October 2, 2001) As the network-computing infrastructure expands around the world, information stor- age systems are becoming key elements of information technology (IT). The amount of original information created in 2000 has been estimated at about 5 EB, and there is now a worldwide information stock of about 100 EB. Commercial models of hard disk drives (HDDs) now have 18 million times the magnetic recording density of the world’s first hard disk drive and are the only candidate solution for storing the bulk of the world’s information stock. In this paper, we analyze the size of the information stock and the future capacity of HDD media. We also describe Fujitsu’s breakthrough tech- nology of synthetic ferrimagnetic media (SFM), which can extend the recording limit to up to 300 Gbit/in2. 1. Introduction will be generated will make storage device tech- Fujitsu has announced an aggressive plan to nology as important as data processing and capitalize on the exploding demand for hard disk transmitting technologies. drive (HDD) products for enterprise servers, work- Analog information has a very limited value stations, and non-traditional applications. The in the network society; however, currently only 3% growth within the compact HDD segment, for ex- of the information stock is in digital form. Among ample, in the emerging market for smaller hard the various storage devices, only HDDs will be able drives in consumer-oriented appliances, audio- to store all of the worldwide information stock in video products, and other non-PC applications, is digital form. strong. To accommodate this new push, Fujitsu The history of Fujitsu’s HDD storage sub- will shift development, manufacturing, and sales system business started in 1965 with the shipment resources away from the 3.5-inch ATA desktop of the first F631. Then, in 1994, Fujitsu entered drive market, which recorded an industry-wide the desktop PC HDD market for desktop PCs by negative growth in the first half of 2001. starting high-volume offshore assembly in South- The evolution of electronics technology in the east Asia. Since then, Fujitsu has become a 20th century enabled great advances in informa- vertically integrated manufacturer of HDDs, in- tion network systems (i.e., computers, telecommu- volved in all aspects: from research and nications equipment, and mass storage). Now, we development to manufacturing of key compo- are approaching the stage when there will be suf- nents.1) The HDD is a typical technology-driven ficient capacity to store the entire worldwide stock device, so the ability to do advanced R&D is es- of information in digital form. We are at the be- sential for maintaining competitiveness in this ginning of the broadband information network era, area. Because of the slump in the PC market, and the enormous amounts of information that Fujitsu has decided to terminate its 3.5-inch ATA FUJITSU Sci. Tech. J.,37,2,p.111-125(December 2001) 111 Y. Miura: Information Storage for the Broadband Network Era - Fujitsu’s Challenge in Hard Disk Drive Technology - HDD business and focus on HDDs for the enter- evolution of these three fundamentals in terms of prise segment (AL-series), mobile HDDs the areal density of hard disk drives, CPU clock (HN-series), 2.5-inch HDDs for desktop PCs, and frequency, and the traffic speed of access lines to emerging HDD application markets.2),3) the home. The values are normalized to the val- An HDD looks like a simple device, but actu- ues in 2000. The HDD business has been driven ally it is an integration of various key components by the expanding PC business, but the current and advanced technologies, for example, giant rapid progress of recording technology has caused magnetoresistive (GMR) heads and inductive some people to say that HDDs are “over-technology write elements, a head positioning servo, spindle products” for PCs. However, to enable the mass motor and actuator mechanisms, drive control and flow of movie information, there will be a strong interface systems, design and manufacturing pro- demand for PC storage capacities exceeding cesses of wafers, low-noise media design, materials 100 GB. HDD video recorders and home servers for heads and media, an ultra-narrow head-to-disk will be big emerging HDD markets in the near spacing, and signal processing. future.6),7) Working in light of the predicted “superpara- Much of our lives is now defined by our rela- magnetic” limit on recording density, Fujitsu has tionship with the Internet. Conventional postal led the academic world by demonstrating record- mail is called “snail mail” because it is much slower breaking densities on a yearly basis. For example, than e-mail, which has become the standard meth- in 1996 we achieved 5 Gbit/in2 and in August od of written communication. Figure 2 shows the 2001 we demonstrated the milestone density of growth of World Wide Web (WWW) sites and e- 106 Gbit/in2.4),5) mail boxes. There are now more than 100 million In this paper, we look at the worldwide infor- WWW sites and 500 million e-mail boxes. It is mation stock and the media that is used to store estimated that between 600 billion and 1100 bil- it. Then, we discuss the future of information stor- lion e-mail messages were sent last year.8) age in the broadband network world. Finally, we There will be a big discussion about whether give an overview of Fujitsu’s latest challenges in local or personal storage will become dominant in advanced magnetic recording technology for a broadband environment. A rapid increase in the HDDs. number of Internet Web sites requires not only This paper refers to a very wide range of num- an increase in the number of network servers, but bers, the meanings of which are as follows: also a huge storage capacity. This requirement MB (Megabyte) = 106 bytes 100 9 GB (Gigabyte) = 10 bytes 100 Mb/s 2 TB (Terabyte) = 1012 bytes 10 300 Gbit/in 15 PB (Petabyte) = 10 bytes 1 CPU clock 18 EB (Exabyte) = 10 bytes 100 MHz 0.1 HDD areal density 2. Emerging broadband 0.01 Relative performance network technology 0.001 Internet (home) transfer ˜ The expansion of high-speed access lines to 0.0001 the home marks the beginning of the broadband 1985 1990 1995 2000 2005 2010 network era. Information storage, processing, and Year transport are three of the fundamentals of infor- Figure 1 mation technology (IT). Figure 1 shows the Performance comparison of key technologies. 112 FUJITSU Sci. Tech. J.,37, 2,(December 2001) Y. Miura: Information Storage for the Broadband Network Era - Fujitsu’s Challenge in Hard Disk Drive Technology - makes high-performance, high-reliability HDDs and they will eventually form the huge network for server applications much more important. computer shown in Figure 4. Personal information storage will also increase. A storage area network (SAN) is a dedicat- Information storage will change the structure of ed, centrally managed, secure information society itself and will occupy a major position in infrastructure that enables any-to-any connec- the social infrastructure. Figure 3 shows an im- tions between servers and storage systems. The age of the future information network era. move to SANs has been motivated by the need to Processors, networks, and information storages manage the dramatically increasing volume of are the key driving force for the broadband era, business data and to mitigate its effect on net- work performance. Distributed computing, client/ 10 000 10 000 server applications, and open systems give today’s 1000 1000 100 100 10 mail boxes (million) Storage ⋅ 10 ˜˜1 ˜˜ 1 0.1 domains Data at rest ⋅ 0.01 0.1 Information storage (PB) Network Processor 0.001 0.01 Contents˜ WWW sites 1995 2000 2005 2010 Data being˜ Data being ˜ Year service˜ ˜ transferred transformed Number of hosts (million) Number of Web sites (million) Number of e-mail boxes (million) Storage amount in surface Web (Pbyte) Storage amount in deep Web (Pbyte) Figure 4 Storage amount in e-mail boxes (Pbyte) Key engines for the information network era. Figure 2 Internet and e-mail growth. Figure 3 Image of information network era. FUJITSU Sci. Tech. J.,37, 2,(December 2001) 113 Y. Miura: Information Storage for the Broadband Network Era - Fujitsu’s Challenge in Hard Disk Drive Technology - enterprises the power to fully integrate hardware sists of the AL-7LE devices, which have 10 krpm and software from different vendors to create sys- drives, 18 to 73 GB capacities, and 3-inch media tems tailored to their specific needs. These and the AL-7LX devices, which have new 15 krpm systems can be fast, efficient, and capable of pro- high-end drives, 18 to 36 GB capacities, and viding a competitive edge.9) 2.75-inch (70 mm diameter) media. The AL-7 se- With the explosive growth of e-business, IT ries devices have Ultra160 SCSI and 2 Gb/s Fibre managers are working hard to keep up with the Channel interfaces.2) We believe the AL-7 series exabytes of new data being created every year. will meet the demands of rapidly growing network They are installing high-performance storage sys- storage systems. tems to meet the demands for smaller backup windows and greater application availability. To 3. The information stock and improve data access and reduce costs, IT manag- digital storage ers are now seeking innovative ways to simplify In this section we investigate how much in- storage management. The SAN is a promising formation there is in the world and whether it can solution for universal access.