Lecture Notes on Hard Disk
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Active@ Boot Disk User Guide Copyright © 2008, LSOFT TECHNOLOGIES INC
Active@ Boot Disk User Guide Copyright © 2008, LSOFT TECHNOLOGIES INC. All rights reserved. No part of this documentation may be reproduced in any form or by any means or used to make any derivative work (such as translation, transformation, or adaptation) without written permission from LSOFT TECHNOLOGIES INC. LSOFT TECHNOLOGIES INC. reserves the right to revise this documentation and to make changes in content from time to time without obligation on the part of LSOFT TECHNOLOGIES INC. to provide notification of such revision or change. LSOFT TECHNOLOGIES INC. provides this documentation without warranty of any kind, either implied or expressed, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. LSOFT may make improvements or changes in the product(s) and/or the program(s) described in this documentation at any time. All technical data and computer software is commercial in nature and developed solely at private expense. As the User, or Installer/Administrator of this software, you agree not to remove or deface any portion of any legend provided on any licensed program or documentation contained in, or delivered to you in conjunction with, this User Guide. LSOFT.NET logo is a trademark of LSOFT TECHNOLOGIES INC. Other brand and product names may be registered trademarks or trademarks of their respective holders. 2 Active@ Boot Disk User Guide Contents 1.0 Product Overview .......................................................................................................... -
Section 10 Flash Technology
10 FLASH TECHNOLOGY Overview Flash memory technology is a mix of EPROM and EEPROM technologies. The term “flash” was chosen because a large chunk of memory could be erased at one time. The name, therefore, distinguishes flash devices from EEPROMs, where each byte is erased individually. Flash memory technology is today a mature technology. Flash memory is a strong com- petitor to other memories such as EPROMs, EEPROMs, and to some DRAM applications. Figure 10-1 shows the density comparison of a flash versus other memories. 64M 16M 4M DRAM/EPROM 1M SRAM/EEPROM Density 256K Flash 64K 1980 1982 1984 1986 1988 1990 1992 1994 1996 Year Source: Intel/ICE, "Memory 1996" 18613A Figure 10-1. Flash Density Versus Other Memory How the Device Works The elementary flash cell consists of one transistor with a floating gate, similar to an EPROM cell. However, technology and geometry differences between flash devices and EPROMs exist. In particular, the gate oxide between the silicon and the floating gate is thinner for flash technology. It is similar to the tunnel oxide of an EEPROM. Source and INTEGRATED CIRCUIT ENGINEERING CORPORATION 10-1 Flash Technology drain diffusions are also different. Figure 10-2 shows a comparison between a flash cell and an EPROM cell with the same technology complexity. Due to thinner gate oxide, the flash device will be more difficult to process. CMOS Flash Cell CMOS EPROM Cell Mag. 10,000x Mag. 10,000x Flash Memory Cell – Larger transistor – Thinner floating gate – Thinner oxide (100-200Å) Photos by ICE 17561A Figure 10-2. -
Active@ UNDELETE Documentation
Active @ UNDELETE Users Guide | Contents | 2 Contents Legal Statement.........................................................................................................5 Active@ UNDELETE Overview............................................................................. 6 Getting Started with Active@ UNDELETE.......................................................... 7 Active@ UNDELETE Views And Windows...................................................................................................... 7 Recovery Explorer View.......................................................................................................................... 8 Logical Drive Scan Result View..............................................................................................................9 Physical Device Scan View......................................................................................................................9 Search Results View...............................................................................................................................11 File Organizer view................................................................................................................................ 12 Application Log...................................................................................................................................... 13 Welcome View........................................................................................................................................14 Using -
Storage Systems and Technologies - Jai Menon and Clodoaldo Barrera
INFORMATION TECHNOLOGY AND COMMUNICATIONS RESOURCES FOR SUSTAINABLE DEVELOPMENT - Storage Systems and Technologies - Jai Menon and Clodoaldo Barrera STORAGE SYSTEMS AND TECHNOLOGIES Jai Menon IBM Academy of Technology, San Jose, CA, USA Clodoaldo Barrera IBM Systems Group, San Jose, CA, USA Keywords: Storage Systems, Hard disk drives, Tape Drives, Optical Drives, RAID, Storage Area Networks, Backup, Archive, Network Attached Storage, Copy Services, Disk Caching, Fiber Channel, Storage Switch, Storage Controllers, Disk subsystems, Information Lifecycle Management, NFS, CIFS, Storage Class Memories, Phase Change Memory, Flash Memory, SCSI, Caching, Non-Volatile Memory, Remote Copy, Storage Virtualization, Data De-duplication, File Systems, Archival Storage, Storage Software, Holographic Storage, Storage Class Memory, Long-Term data preservation Contents 1. Introduction 2. Storage devices 2.1. Storage Device Industry Overview 2.2. Hard Disk Drives 2.3. Digital Tape Drives 2.4. Optical Storage 2.5. Emerging Storage Technologies 2.5.1. Holographic Storage 2.5.2. Flash Storage 2.5.3. Storage Class Memories 3. Block Storage Systems 3.1. Storage System Functions – Current 3.2. Storage System Functions - Emerging 4. File and Archive Storage Systems 4.1. Network Attached Storage 4.2. Archive Storage Systems 5. Storage Networks 5.1. SAN Fabrics 5.2. IP FabricsUNESCO – EOLSS 5.3. Converged Networking 6. Storage SoftwareSAMPLE CHAPTERS 6.1. Data Backup 6.2. Data Archive 6.3. Information Lifecycle Management 6.4. Disaster Protection 7. Concluding Remarks Acknowledgements Glossary Bibliography Biographical Sketches ©Encyclopedia of Life Support Systems (EOLSS) INFORMATION TECHNOLOGY AND COMMUNICATIONS RESOURCES FOR SUSTAINABLE DEVELOPMENT - Storage Systems and Technologies - Jai Menon and Clodoaldo Barrera Summary Our world is increasingly becoming a data-centric world. -
Chapter 12: Mass-Storage Systems
Chapter 12: Mass-Storage Systems Overview of Mass Storage Structure Disk Structure Disk Attachment Disk Scheduling Disk Management Swap-Space Management RAID Structure Disk Attachment Stable-Storage Implementation Tertiary Storage Devices Operating System Issues Performance Issues Objectives Describe the physical structure of secondary and tertiary storage devices and the resulting effects on the uses of the devices Explain the performance characteristics of mass-storage devices Discuss operating-system services provided for mass storage, including RAID and HSM Overview of Mass Storage Structure Magnetic disks provide bulk of secondary storage of modern computers Drives rotate at 60 to 200 times per second Transfer rate is rate at which data flow between drive and computer Positioning time (random-access time) is time to move disk arm to desired cylinder (seek time) and time for desired sector to rotate under the disk head (rotational latency) Head crash results from disk head making contact with the disk surface That’s bad Disks can be removable Drive attached to computer via I/O bus Busses vary, including EIDE, ATA, SATA, USB, Fibre Channel, SCSI Host controller in computer uses bus to talk to disk controller built into drive or storage array Moving-head Disk Mechanism Overview of Mass Storage Structure (Cont.) Magnetic tape Was early secondary-storage medium Relatively permanent and holds large quantities of data Access time slow Random access ~1000 times slower than disk Mainly used for backup, storage of infrequently-used data, transfer medium between systems Kept in spool and wound or rewound past read-write head Once data under head, transfer rates comparable to disk 20-200GB typical storage Common technologies are 4mm, 8mm, 19mm, LTO-2 and SDLT Disk Structure Disk drives are addressed as large 1-dimensional arrays of logical blocks, where the logical block is the smallest unit of transfer. -
Chapter 3. Booting Operating Systems
Chapter 3. Booting Operating Systems Abstract: Chapter 3 provides a complete coverage on operating systems booting. It explains the booting principle and the booting sequence of various kinds of bootable devices. These include booting from floppy disk, hard disk, CDROM and USB drives. Instead of writing a customized booter to boot up only MTX, it shows how to develop booter programs to boot up real operating systems, such as Linux, from a variety of bootable devices. In particular, it shows how to boot up generic Linux bzImage kernels with initial ramdisk support. It is shown that the hard disk and CDROM booters developed in this book are comparable to GRUB and isolinux in performance. In addition, it demonstrates the booter programs by sample systems. 3.1. Booting Booting, which is short for bootstrap, refers to the process of loading an operating system image into computer memory and starting up the operating system. As such, it is the first step to run an operating system. Despite its importance and widespread interests among computer users, the subject of booting is rarely discussed in operating system books. Information on booting are usually scattered and, in most cases, incomplete. A systematic treatment of the booting process has been lacking. The purpose of this chapter is to try to fill this void. In this chapter, we shall discuss the booting principle and show how to write booter programs to boot up real operating systems. As one might expect, the booting process is highly machine dependent. To be more specific, we shall only consider the booting process of Intel x86 based PCs. -
Chapter 16 Disk Storage, Basic File Structures, Hashing, and Modern Storage
Chapter 16 Disk Storage, Basic File Structures, Hashing, and Modern Storage - Databases are stored as files of records stored on disks - Physical database file structures - Physical levels of three schema architecture 1 - The collection of data in a DB must be stored on some storage medium. The DBMS software can retrieve, update, and process this data as needed - Storage media forms a hierarchy 2 -primary, secondary, tertiary, etc.. - offline storage, archiving databases (larger capacity, less cost, slower access, not directly accessible by CPU) Memory Hierarchies and Storage Devices - Cache, static RAM (Prefetch, Pipeline) - Dynamic RAM (main memory( Secondary and Tertiary Storage -mass storage (magnetic disks, CD, DVD (measured in KB, MB, TB, PB - programs are in main memory (DRAM) -permanent databases reside in secondary storage - main memory buffers are used to read and write to secondary storage - Flash memory: non volatile, NAND and NOR flash based - Optical disks: CDs (700MB) and DVDs (4.5 – 15GB), Blue Ray (54GB) - Magnetic Tapes and Juke Boxes Depending upon the intended use and application requirements, data is kept in one or more levels of hierarchy 3 Storage Organization of Database -Large amount of data that must persist for a long period of time (called persistent data) - parts of this data are accessed and processed repeatedly during the storage period - transient data during the period of execution - most DBs are stored on secondary storage (magnetic disks) - DB is too large to fit in main memory - permanent loss on disk is less likely - less cost on disk than primary storage 4 5 6 - A range of cylinders have the same number of sectors per arc. -
Use External Storage Devices Like Pen Drives, Cds, and Dvds
External Intel® Learn Easy Steps Activity Card Storage Devices Using external storage devices like Pen Drives, CDs, and DVDs loading Videos Since the advent of computers, there has been a need to transfer data between devices and/or store them permanently. You may want to look at a file that you have created or an image that you have taken today one year later. For this it has to be stored somewhere securely. Similarly, you may want to give a document you have created or a digital picture you have taken to someone you know. There are many ways of doing this – online and offline. While online data transfer or storage requires the use of Internet, offline storage can be managed with minimum resources. The only requirement in this case would be a storage device. Earlier data storage devices used to mainly be Floppy drives which had a small storage space. However, with the development of computer technology, we today have pen drives, CD/DVD devices and other removable media to store and transfer data. With these, you store/save/copy files and folders containing data, pictures, videos, audio, etc. from your computer and even transfer them to another computer. They are called secondary storage devices. To access the data stored in these devices, you have to attach them to a computer and access the stored data. Some of the examples of external storage devices are- Pen drives, CDs, and DVDs. Introduction to Pen Drive/CD/DVD A pen drive is a small self-powered drive that connects to a computer directly through a USB port. -
Olympus Optical Disc Archiving Systems & Discstor 900 Optical
Olympus Optical Disc Archiving Systems & DiscStor 900 Optical Disc Storage System Solution Overview All Pro Solutions, Inc. | 1351 E. Black Street, Rock Hill, SC 29730 USA | Tel: +1.803.980.4141 | Web: www.allprosolutions.com | Email: [email protected] The Company – All Pro Solutions, Inc. – Leading manufacturer of automated disc duplicating, printing & publishing systems. – Started in 1996 manufacturing floppy disk duplication systems. – Family-owned and operated. – In South Carolina since 2009. – Provides services like document scanning, imaging, converting. – Expanded into data storage and archiving industry. – Whatever the problem, we find a solution. All Pro Solutions, Inc. | 1351 E. Black Street, Rock Hill, SC 29730 USA | Tel: +1.803.980.4141 | Web: www.allprosolutions.com | Email: [email protected] The Challenge Worldwide Corporate Data Growth Unstructured text Structured data Source: IDC The Digital Universe 2010 80% of Corporate Data is Unstructured File Data Active Less Active Inactive Hot Cold 10% Warm 20% 70% All Pro Solutions, Inc. | 1351 E. Black Street, Rock Hill, SC 29730 USA | Tel: +1.803.980.4141 | Web: www.allprosolutions.com | Email: [email protected] The Solution Blu-Ray Disc – The ideal media for long-term archival • Longevity • Capacity - Extendable • Security • Removability • Data Migration • Accessibility • Compliance • Compatibility • Green Technology • Power Consumption Networked Client Workstations LAN Primary Network Servers All Pro Solutions, Inc. | 1351 E. Black Street, Rock Hill, SC 29730 USA | Tel: +1.803.980.4141 | Web: www.allprosolutions.com | Email: [email protected] The Solution Blu-Ray Disc – The ideal media for long-term archival • Longevity • Capacity - Extendable • Security • Removability • Data Migration • Accessibility • Compliance • Compatibility • Green Technology • Power Consumption Networked Client Workstations Olympus Archiving System LAN DiscStor 900 Storage System Primary Network Servers All Pro Solutions, Inc. -
Secure Data Storage – White Paper Storage Technologies 2008
1 Secure Data Storage – White Paper Storage Technologies 2008 Secure Data Storage - An overview of storage technology - Long time archiving from extensive data supplies requires more then only big storage capacity to be economical. Different requirements need different solutions! A technology comparison repays. Author: Dr. Klaus Engelhardt Dr. K. Engelhardt 2 Secure Data Storage – White Paper Storage Technologies 2008 Secure Data Storage - An overview of storage technology - Author: Dr. Klaus Engelhardt Audit-compliant storage of large amounts of data is a key task in the modern business world. It is a mistake to see this task merely as a matter of storage technology. Instead, companies must take account of essential strategic and economic parameters as well as legal regulations. Often one single technology alone is not sufficient to cover all needs. Thus storage management is seldom a question of one solution verses another, but a combination of solutions to achieve the best possible result. This can frequently be seen in the overly narrow emphasis in many projects on hard disk-based solutions, an approach that is heavily promoted in advertising, and one that imprudently neglects the considerable application benefits of optical storage media (as well as those of tape-based solutions). This overly simplistic perspective has caused many professional users, particularly in the field of long-term archiving, to encounter unnecessary technical difficulties and economic consequences. Even a simple energy efficiency analysis would provide many users with helpful insights. Within the ongoing energy debate there is a simple truth: it is one thing to talk about ‘green IT’, but finding and implementing a solution is a completely different matter. -
Control Design and Implementation of Hard Disk Drive Servos by Jianbin
Control Design and Implementation of Hard Disk Drive Servos by Jianbin Nie A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering-Mechanical Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Roberto Horowitz, Chair Professor Masayoshi Tomizuka Professor David Brillinger Spring 2011 Control Design and Implementation of Hard Disk Drive Servos ⃝c 2011 by Jianbin Nie 1 Abstract Control Design and Implementation of Hard Disk Drive Servos by Jianbin Nie Doctor of Philosophy in Engineering-Mechanical Engineering University of California, Berkeley Professor Roberto Horowitz, Chair In this dissertation, the design of servo control algorithms is investigated to produce high-density and cost-effective hard disk drives (HDDs). In order to sustain the continuing increase of HDD data storage density, dual-stage actuator servo systems using a secondary micro-actuator have been developed to improve the precision of read/write head positioning control by increasing their servo bandwidth. In this dissertation, the modeling and control design of dual-stage track-following servos are considered. Specifically, two track-following control algorithms for dual-stage HDDs are developed. The designed controllers were implemented and evaluated on a disk drive with a PZT-actuated suspension-based dual-stage servo system. Usually, the feedback position error signal (PES) in HDDs is sampled on some spec- ified servo sectors with an equidistant sampling interval, which implies that HDD servo systems with a regular sampling rate can be modeled as linear time-invariant (LTI) systems. However, sampling intervals for HDD servo systems are not always equidistant and, sometimes, an irregular sampling rate due to missing PES sampling data is unavoidable. -
Chapter 9: Peripheral Devices—Overview D a 2/E
C S Chapter 9: Peripheral Devices—Overview D A 2/e Magnetic disk drives: ubiquitous and complex Other moving media devices: tape and CD ROM Display devices Video monitors: analog characteristics Video terminals Memory mapped video displays Flat panel displays Printers: dot matrix, laser, inkjet Manual input: keyboards and mice A to D and D to A converters: the analog world Computer Systems Design and Architecture Second Edition © 2004 Prentice Hall C S Tbl 9.1 Some Common Peripheral Interface D Standards A 2/e Bus Standard Data Rate Bus Width Centronics ~50KB/s 8-bit parallel EIA RS232/422 30-20K B/s bit-serial SCSI 10-500 MB/s 16-bit parallel Ethernet 10-1000 Mb/s bit-serial USB 1.5-12 Mb/s bit-serial USB-2 480 Mb/s bit-serial FireWire† 100-400 Mb/s bit-serial FireWire-800† 800 Mb/s bit-serial †Also known as Sony iLink, or IEEE1394 and 1394b, respectively Computer Systems Design and Architecture Second Edition © 2004 Prentice Hall C S Disk Drives—Moving Media Magnetic D Recording A 2/e High density and non-volatile Densities approaching semiconductor RAM on an inexpensive medium No power required to retain stored information Motion of medium supplies power for sensing More random access than tape: direct access Different platters selected electronically Track on platter selected by head movement Cyclic sequential access to data on a track Structured address of data on disk Drive: Platter: Track: Sector: Byte Computer Systems Design and Architecture Second Edition © 2004 Prentice Hall C S Fig 9.3 Cutaway View of a Multi-Platter