Strategic directions in storage I/O issues in large-scale computing

Magnetic recording is potentially superior to optical recording with respect to recording density. However, to realize the full potential of magnetic disk storage devices, it is necessary to lower the head flying height from the submicrometer range to the sub-submicrometer range. In order to maintain the head at a safe sub-submicrometer flying height, it is necessary to solve the problem of head and medium wear. Consequently, the study of micro-tribology is essential for the development of magnetic recording capability. Compared with magnetic disk drives, optical disk drives have longer seek times and lower data rates. To enhance the seek time and data rate, electromechanics and servo-control technologies are the main concern. Advances in magnetic disk storage devices can be expected in the area of fixed-media on-line files. In contrast, the strong point of optical disk storage devices is their media-interchangeability. New optical disk applications which exploit this special feature can be expected.

This paper proposes a virtual optical disk method which uses the write‐once optical disk as a rewritable secondary memory on existing operating systems. The method also provides revision history of all files on an optical disk. The virtual disk method realizes a virtually rewritable disk (virtual disk), using the write‐once optical disk. The rewriting is simulated using the disk sector as the unit. It completes re‐writability and revision control without additional rewritable memory devices such as magnetic disks. The method is actually built into an OS for a personal computer, and the access speed of a virtual disk is made almost equal to that of a floppy disk by adding an optical disk cache memory. The virtual disk method has a merit in that it can cope with write‐errors in a write‐once optical disk, which may occur consecutively at writing process. Thus, it is seen that the virtual optical disk method is a useful means of this medium management.

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An atomic force microscope-based nanoscratch testing technique has been applied to evaluate scratch resistance of 100 Å thick protective overcoats on hard magnetic disks. Among the overcoats prepared by dc magnetron sputtering, an amorphous nitrogenated carbon (a-C:N) film showed the best performance in the tests, followed by an amorphous hydrogenated carbon (a-C:H) film and an undoped amorphous carbon (a-C) film. Substrate temperature in the overcoat sputtering process was found to be an important factor affecting the film’s scratch resistance. Overcoats sputtered at lower substrate temperature were more stable against scratching. An ion beam deposition process was found to produce an overcoat with superior scratch-resistant properties as compared to the sputtered carbon overcoats. Nanoscale scratch testing results are correlated with the sp3-bonding character in the overcoats assessed by Raman spectroscopy.

For over eight years Burroughs Corporation has designed and manufactured random access bulk storage devices. The first two such devices produced were the Burroughs 205 and 220 Datafile units. They were magnetic tape storage devices in which a common read/write head was positioned to one of fifty strips of magnetic tape. After head positioning, finding the information in question was the same as searching for a record on a conventional magnetic tape unit.

Developments in marine seismic data acquisition technology have made available streamer systems with 1000 channels and high sampling frequency. The resulting data rates and volumes are above the capacity of the current magnetic tape recording systems. The recording requirements of high rate seismic systems could be met through developments in laser disc technology, in the area of magnetic tape systems or through online pre-processors reducing the amount of data. New recording technologies are essential for the feasibility of high rate seismic systems. INTRODUCTION Industry demand for increased resolution of offshore seismic surveys has resulted in development of more sophisticated acquisition systems. Digital streamers have made possible significant increases in spatial and temporal sampling rates. Some streamer systems provide the possibility of recording up to 1000 channels in addition to high temporal sampling rates. These developments have led to significantly higher data rates than common in marine seismic data recording today. Standard computer readable magnetic tape, which is well known to the seismic industry, is still the state-of-the-art medium for recording of seismic data. Even though this technology has remained essentially the same for several years, it has so far proved to be reliable and sufficient. Unchanged, however~ it will not be adequate for the kind of high rate seismic data recording indicated above. Implementation of new recording technologies is therefore essential to the feasibility and cost effectiveness of high rate seismic acquisition systems The increased recording density and speed requirements of high rate acquisition systems can be met in several ways; through new developments in laser disc technology, in magnetic computer tape technology resulting in magnetic tape systems with higher data rate and density, or through the use of high density digital recorders to seismic data acquisition. Another attractive alternative is to use online pre-processors to perform data reduction to match the recorded data volume to the capabilities of current magnetic tape systems. However, online pre-processing is a large subject which we will leave out of this paper. In this paper we will discuss the use of these recording systems for high rate seismic recording and the status of their development. However, we will begin with a review of some geophysical and operational reasons for using high rate seismic recording. SOME GEOPHYSICAL ASPECTS. Increasing production and development costs of off-shore oil fields have forced many oil companies into careful evaluation of new fields and reevaluation of existing fields currently in production. To meet the required data quality may in some areas require fine spatial sampling intervals of the seismic data, in some cases significantly less than 10 m. The Delphi Survey respondents (Hewitt, 1983) predicted that 25 percent of recording systems in use by 1990 will have at least 1000 channel capability and that this percentage could increase to 50 by 1995.

The main goal of our research was to establish the extent to which recordings on magnetic tapes and optical discs were incorporated into library materials offered by public libraries, which are located in the area of the municipal community of Ljubljana. Using the statistical summary books, issued by public libraries, we gathered and analysed the accretion, stocks and borrowing figures of monographic publications, audio cassettes, compact discs, video cassettes and CD-ROMs. The findings show that monographic publications are still the fundamental material of public libraries. Among audio-visual media, video cassettes represent the most extensive collection, followed in number by compact discs, audio cassettes and finally CD-ROMs. The results of the analysis of borrowed library material are totally consistent with the above stated order. Quantitative measuring has also shown that the stocks of audio-visual materials do not reach the international standards for public libraries.

You have accessThe ASHA LeaderBottom Line1 Sep 2011Patient Information Privacy Basics Kate RomanowJD Kate Romanow Google Scholar More articles by this author , JD https://doi.org/10.1044/leader.BML1.16092011.3 SectionsAbout ToolsAdd to favorites ShareFacebookTwitterLinked In ASHA recently hosted an online private-practice institute for audiologists and speech-language pathologists that focused on how to establish, manage, and grow a profitable private practice. Recorded lectures covered topics such as strategic business planning, fees and pricing, employment law basics, managing a fee-for-service practice, increasing referrals, using web-based and social media marketing, coding updates, Medicare billing, and claims and denials. Many of the participants in one of the sessions, “Data Privacy, Security, and Enforcement: HIPAA and More,” raised several questions during and after the institute on the Health Insurance Portability and Accountability Act (HIPAA). This article clarifies points discussed during the institute to help other clinicians understand HIPAA policies. The HIPAA privacy rule protects personal health information and outlines patients’ rights with respect to that information, while allowing disclosure of information needed for patient care. The HIPAA security rule specifies a series of administrative, physical, and technical safeguards that ensure the confidentiality, integrity, and availability of electronic protected health information. Electronic protected health information includes, for example, patient data stored on a computer hard drive, or data transmitted via a computer for billing purposes. The following questions and answers outline basic HIPAA privacy and security regulations. Q: Do the HIPAA regulations apply to me? HIPAA compliance is required by all “covered entities,” defined as health plans, health care clearinghouses, and health care providers that transmit any health information in electronic form in connection with “transactions” covered under HIPAA. If you are a provider who, for example, sends patient information electronically to a billing company, then you are a “covered entity” and must comply with HIPAA regulations. Q: What transactions are covered under HIPAA? HIPAA regulations define “transaction” as the transmission of information between two parties to carry out financial or administrative activities related to health care. It includes the following types of information transmissions: Health care claims or equivalent encounter information. Health care payment and remittance advice. Coordination of benefits. Health care claim status. Enrollment and disenrollment in a health plan. Eligibility for a health plan. Health plan premium payments. Referral certification and authorization. First report of injury. Health claims attachments. Other transactions that the secretary of health and human services may prescribe by regulation (45 C.F.R. Section 160.103). Q: What does “electronic form” mean? HIPAA does not define “electronic form.” It does, however, define “electronic media” as the following: Electronic storage media including memory devices in computers (hard drives) and any removable/transportable digital memory medium, such as magnetic tape or disk, optical disk, or digital memory card. Transmission media used to exchange information already in electronic storage media. Transmission media include, for example, the Internet, extranet (using Internet technology to link a business with information accessible only to collaborating parties), dial-up lines, leased lines, private networks, and the physical movement of removable/transportable electronic storage media. Certain transmissions, including those by paper (facsimile) and by voice (telephone), are not considered e-transmissions via electronic media because the information did not exist in electronic form before the transmission (45 C.F.R. Section 160.103). Q: If I am a covered entity, what do I need to do to comply with HIPAA? You must protect the privacy of patient information. You must safeguard patient information sent electronically. For example, you must inform patients about the HIPAA privacy practices you observe and train employees about HIPAA requirements. Q: Are there sample notices of privacy practices? More information about HIPAA privacy notices is available at the Department of Health and Human Services website. ASHA includes a sample notice of privacy practices in its Practice Management Tools for SLPs available in the ASHA online store. Q: Where I can get more information? ASHA’s reimbursement web page includes an extensive section on HIPAA. An article in The ASHA Leader also outlines some basics. The Office of Civil Rights, which enforces the privacy and security rule, has information on its website. The Workgroup for Electronic Data Interchange [PDF] (of which ASHA is a member) has information to help small practices comply with HIPAA. The full HIPAA regulations are available at the Department of Health and Human Services website. (Be aware, however, that the most current version may not be posted.) Author Notes Kate Romanow, JD, director of health care regulatory advocacy, can be reached at [email protected]. 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Ever since the dawn of human being, variety of media such as stone, parchment, bamboo, woods, paper, magneto, optical and electric has been used for recording information. Among those, the optical discs initially started from audio CD in early 1980s, has 12 cm diameter, still playing prominent roles for long term with its stable format, despite the continued evolution of electronic products. The recordable optical discs has also been used for data storage and data distribution for more than 20 years showing its continued strong demand over 10 billion discs every year. Its applications are broadly ranged such as audio, video, PC and digital information.Though optical discs have less capacity and slower transfer rate than hard disk drives and magnetic tape, they have great deal of potential for application of long term archiving.This report discusses the use of optical discs as archiving media and trends in its standardization towards it. As an example, this paper also examines the recovery of discs damaged by the Great East Japan Earthquake.

Direct access storage devices (DASDs) are widely used in the computer industry to store and manage data. In conventional magnetic recording, an induction head flying very close to the disk surface alters the polarization of the magnetic field of the disk surface to erase and/or write the information on the disk. However, a new technology known as magneto-optical recording or optical recording has considerable promise to increase data densities and reliability of data storage. In magneto-optical storage, magnetic fields are altered by a laser source, which heats the magnetic medium beyond its Curie point, a temperature at which the magnetic medium loses its magnetization. This domain with zero magnetization is subsequently reversed by using an induction magnet. All these processes take place when the disk is rotating at a very high speed with respect to the laser source. An optical disk is a multilayered medium consisting of a thick glass disk on which many layers of different materials are sputtered, only one layer of which serves as a magnetic medium. Therefore, in this paper, a problem of laser-induced heating of a multilayered medium resting on a half-space is considered when the laser is translating with respect to it. The transient heat conduction equation is solved by employing the Laplace transform in the time domain and the Fourier Transform in the x, y dimensions. The resulting ordinary differential equation is solved and the inversion of the Laplace transform is obtained by a technique developed by Crump. The Fourier inversion is obtained by using a Fast Fourier Transform. The technique developed here is then applied to calculate domain size for recorded bits for a given disk, laser power, source characteristics, and rotational velocity.

Our age is one of gadgetry, and so it is not at tall unusual that teachers of languages have become conditioned to the use of mechanical and electronic devices to supplement the work of the classroom. There seems to be very little apprehension that the machine will eventually displace the teacher; therefore it can be accepted calmly as the aid which it is and can be assigned its proper role. Indeed, the modern language teacher today is under some compulsion to take an interest in the development and use of audio-visual aids. And since language teachers must compete for students, we might say, too, that the use of audio-visual aids has some advertising value in the academic market place. Obviously, few language departments or language teachers command a budget that will enable them to purchase, install and maintain equipment for an elaborate phonetics laboratory or center. This does not mean, however, that only a fortunate few may enjoy the benefits of a listening program. It is possible to organize such a program for elementary German courses if one has nothing more than a magnetic tape recorder and a room where students may come to listen, and where they will not be disturbed by or disturb others. The initial cost of such a tape recorder is quite low, and it should not be too difficult to approach administrators with a request for one. The tape recorder is simple, easy to use, and economical to operate. It is also versatile, for it can be used as a recorder, a playback, and a public address system. The fact that it is easily portable makes it possible to use it anywhere to record speech, music, and particularly interviews with native Germans who might find it inconvenient to come to speak to a class. Where the budget permits the purchase of nothing more than the tape recorder and a few reels of tape, students will have to use the loudspeaker with which the machine is equipped. Often, when several students listen simultaneously to a tape with the aid of the loudspeaker, the effectiveness of the listening experience is reduced. Certain students are under some restraint in the presence

In the recent trend toward high density magnetic recording, magnetic materials used in magnetic recording equiment such as audio tape recorder, VTR, magnetic card device are being replaced by new materials of higher magnetic coercive force. Correspondingly, increasing number of magnetic heads are made of magnetic materials with abrasion resistance or higher magnetic flux density. As for hard magnetic disks for computers, which are required to have higher recording density to meet the trend toward smaller machine size, use of thin film medium with magnet layer formed by plating or spattering is increasing. In floppy disks used in personal computers and word processors on the other hand, perpendicular magnetic recording medium of Co-Cr with higher magnetic coersive force has been introduced. It is expected that thin film head and perpendicular magnetic head will soon be predominant in the field of magnetic head.

The combination of the explosive growth in digital data and the demand to preserve much of these data in the long term has made it imperative to find a more cost-effective way than HDD arrays and a more easily accessible way than tape libraries to store massive amounts of data. While modern optical discs are capable of guaranteeing more than 50-year data preservation without media replacement, individual optical discs’ lack of the performance and capacity relative to HDDs or tapes has significantly limited their use in datacenters. This article presents a Rack-scale Optical disc library System, or ROS in short, which provides a PB-level total capacity and inline accessibility on thousands of optical discs built within a 42U Rack. A rotatable roller and robotic arm separating and fetching discs are designed to improve disc placement density and simplify the mechanical structure. A hierarchical storage system based on SSDs, hard disks, and optical discs is proposed to effectively hide the delay of mechanical operation. However, an optical library file system (OLFS) based on FUSE is proposed to schedule mechanical operation and organize data on the tiered storage with a POSIX user interface to provide an illusion of inline data accessibility. We further optimize OLFS by reducing unnecessary user/kernel context switches inheriting from legacy FUSE framework. We evaluate ROS on a few key performance metrics, including operation delays of the mechanical structure and software overhead in a prototype PB-level ROS system. The results show that ROS stacked on Samba and FUSE as network-attached storage (NAS) mode almost saturates the throughput provided by underlying samba via 10GbE network for external users, as well as in this scenario provides about 53ms file write and 15ms read latency, exhibiting its inline accessibility. Besides, ROS is able to effectively hide and virtualize internal complex operational behaviors and be easily deployable in datacenters.

From the viewpoints of large capacity, long‐term guarantee, and low cost, interest in magnetic recording tapes has undergone a revival as an archive storage media for big data. Herein, we prepared a new series of metal‐substituted ϵ‐Fe2O3, ϵ‐GaIII0.31TiIV0.05CoII0.05FeIII1.59O3, nanoparticles with an average size of 18 nm. Ga, Ti, and Co cations tune the magnetic properties of ϵ‐Fe2O3 to the specifications demanded for a magnetic recording tape. The coercive field was tuned to 2.7 kOe by introduction of single‐ion anisotropy on CoII (S=3/2) along the c‐axis. The saturation magnetization was increased by 44 % with GaIII (S=0) and TiIV (S=0) substitution through the enhancement of positive sublattice magnetizations. The magnetic tape media was fabricated using an actual production line and showed a very sharp signal response and a remarkably high signal‐to‐noise ratio compared to the currently used magnetic tape.

The European Centre for Medium Range Weather Forecasts (ECMWF) has embarked upon a project to provide a back-end file server subsystem to a variety of worker machines ranging from a VAX 11-750 to a CRAY X- MP. The project commenced in mid-1982 with a procurement phase, which lasted almost 12 months and is presently in the implementation phase. It is expected that a significant proportion of the project will be completed during 1984. The file server is based upon IBM architecture and will be connected to the worker machines using a 50 million bits per second proprietary local area network supplied by Control Data Corporation. The file server will support a large meteorological database which currently contains around 2 x 1013 bits of information and which is growing at a rate of 3 x 1012 bits per year. A variety of magnetic storage devices (Disk Mass Storage System and Tape) will provide a hierarchical storage system which is well placed to be able to use new devices as they emerge. The paper will describe in detail the application, and the hardware and software necessary to realise the solution adopted at ECMWF. It will also examine its requirements for new storage devices, with particular emphasis on Optical Digital Data Disk Technology.© (1984) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.