1.1 storage device
- 1. A+ HardwareSection 1.1 Storage DevicesMade By : Gagandeep Singh
- 2. What you learn todayCompTIA A+ 220-701 , Section 1.1 Categories of Storage Devices and Backup - FDD - HDD * Solid State Vs Magnetic - Optical Drives * CD/DVD/RW/ BLUERAY - Removable Storage * Tape Drive * Solid State (e.g. Thumb drive, flash, SD cards, USB) * External CD-RW and Hard Disk Drive * Hot-Swappable device and Non Hot-Swappable device.
- 3. FDD- Floppy Disk Drive
- 4. FDD- Floppy Disk Drive8 inch Floppy Drive5.25 inch Floppy Drive3.5 inch Floppy Drive (1.44 Megabyte, 90mm)
- 5. FDDFloppy disk drive (FDD) is removable storage utilizing a thin, flexible magnetic storage medium, encased in a plastic shell to read and write data.
- 6. While over time drive capacities have changed, today’s standard floppy disk drive size is 1.44 MB.
- 7. Floppy disk drives are quickly going out of standard use, due to the higher capacity, and much cheaper, writeable compact disks.CD DVDCD and DVD-R (or RW, for rewriteable) is removable storage that takes advantage of the higher capacity of optical disks to store information.
- 8. CD-R (and DVD-R) drives utilize a red-light laser to “burn” data onto blank optical discs.
- 9. CD and DVD-R media come in several different types:
- 10. CD-R – Write-Once discs, with a standard size of 700MBs.
- 11. CD-RW – Rewriteable discs, with a standard size of 700MBs.
- 12. DVD-R – Also write-once discs, DVDs have a standard capacity of 4.7 GB. This format includes the DVD-RW, the rewriteable form;DVD Blu-RayDVD+R – Simply another write-once format, not currently approved by the DVD Forum. It also has a rewriteable form, DVD+RW, and a double layer disc with a capacity of almost 8.55 GBs, referred to as DVD+RW DL.
- 13. Blu-Ray – Sony-proprietary optical disc storage medium. Can store high-definition video and audio at a capacity of 50 GB per disc (dual layer) and 25GB ( single layer).
- 14. Drive speeds are as varied as media types and are issued as multiples of the original read speed of the device. CD-ROMs start at 150Kbps, and DVD-ROMs start at 1352.54Kbps. Thus, a 52x CD-ROM reads at 7800Kbps, and a 16x DVD-ROM reads at 21,640KbpsHDD- Hard Disk Drive
- 15. PATA and SATA
- 16. Storage devices and Backup MediaA storage device is, broadly defined, any component your computer uses to permanently store information.
- 17. This is done in a variety of ways by a variety of different components, but generally speaking, storage devices are split into two categories: fixed and removable.Storage devices (HDD Intro)Hard disk drive (HDD) is a fixed, non-volatile storage device that stores information on the magnetic surface of hard disk platters.
- 18. Hard disks are measured in terms of capacity (typically in GB) and in speed (revolutions per minute, or RPMs).
- 19. Today, a typical workstation’s hard drive might have between 40 and 200 GB of storage space rotating at 7,200 to 10,000 RPMs.Storage devices (HDD Intro)Hard disks are usually connected to the computer by one of several different connections:
- 20. ATA – Standard on most desktop computers; IDE (Integrated Device Electronics) and EIDE( Enhanced Integrated Device Electronics) ; cable is a flat, wide ribbon.
- 21. Serial ATA – Provides for faster communication speeds between hard drive and motherboard; it is not backward compatible with the ATA form factor.
- 22. SCSI – Interface allowing the connection of several devices in a chain.Solid State Drives (SSD)
- 23. Solid State Drives (SSD) Solid State Drives does not have moving parts.It have concept of memory chips. So that is why is very fast.Reading and writing is fast and expensive per GB basis.100$ and 100$ spending to buy Solid State Drives. You can buy traditional HDD is same amount and you get 10 times space available on the system. Traditional HDD works slow as SSD.Solid State Drives - Such as thumb, flash and SD drives. Volatile storage (like RAM) utilized for extremely quick access speeds. These are usually used in small, hand-held devices.
- 24. Disk Geometry
- 25. Key Components of a Hard Disk Platters and Media
- 26. Read/Write Heads
- 27. Head Sliders, Arms and Actuator
- 28. Spindle Motor
- 30. Logic Board
- 31. Integrated CachePlattersA hard disk drive consists of on one or more flat circular discs called platters on which data is stored.
- 32. The platters are composed of two main substances:
- 33. A substrate material that forms the majority of the platter and gives the platter a structure and rigidity.
- 34. A magnetic media coating which actually holds the magnetic impulses that represent the data. Read/Write Head The read/write heads of the hard disk are the interface between the magnetic physical media on which the data is stored and the electronic components that make up the rest of the hard disk (and the PC).
- 35. The read/write heads are responsible for converting bits to magnetic pulses and storing them on the platter when data is written on the hard disk.
- 36. The read/write head then again converts back the magnetic pulses stored on the hard disk into bits when data is read from the hard disk. Actuator AssemblyThe read/write heads of a hard disk are responsible for reading data and writing data on the hard disk.
- 37. To perform its task effectively, the read/write head must be held in a fixed position relative to the surface it is reading and should also be allowed to move from track to track to allow access to the entire disk surface area. The surface on which the read/write heads are mounted is called the actuator assembly.
- 38. The actuator assembly looks similar to a comb with its teeth inserted between the platters.Actuator Assembly Cont..An actuator assembly is further composed of three parts: head slider, head arm and actuator.. The component of the actuator assembly on which heads are actually mounted is called the head slider.
- 39. The head arms are all combined together into a single structure that is moved around the surface of the disk by the actuator.
- 40. The actuator is the device used to position the head arms to different tracks on the surface of the platter. Spindle MotorThe spindle motor, also called the spindle shaft, is responsible for moving the platters around that make the hard disk operational.
- 41. The spindle motor provides stable, reliable and consistent turning power to the hard disk to function it properly. Hard Disk Connectors and JumpersJumpers are small devices that are used to directly control the operation of hardware devices, without using any software. A jumper has two main components: Jumper: Jumper itself is a small piece of plastic and metal that is used to connect or remove the hardware device from the computer.
- 42. Jumper Pins: A set of pins, across two of which a jumper is placed to make a specific connection.Power ConnectorHard disk drives use a standard, 4-pin male connector plug to connect to the power connectors coming from the power supply. This power connector for the hard disk provides +5 and +12 voltage to the hard disk.
- 43. Molex Power Connector: Used to power ATA hard disks, CD-ROMS, 5 inch floppy drives and other peripherals.Data Interface ConnectorModern hard disk drives use one of two interfaces: Integrated Drive Electronics (IDE) {also known as AT Attachment (ATA)} and its variants, or Small Computer System Interface (SCSI). However, it can be easily identified which interface is being used by simply looking at the back of the hard disk. This is how you can identify the hard disk interface being used:
- 44. IDE/ATA or its variant hard disks have a 40-pin connector at its back.
- 45. SCSI hard disks have a 50-pin, 68-pin, or 80-pin D-shaped connector at its back. IDE/ATA Configuration Jumpers IDE/ATA hard disks have only a few jumpers and they don't vary greatly from drive to drive. Here are the jumpers you will normally find:Drive Select
- 46. Slave Present
- 47. Cable Select
- 48. Size Restriction JumperLED ConnectorThe hard disks use an LED to indicate its activity. This LED also enables a user to determine whether a system is active or not.
- 49. This hard disk LED is mounted on the computer case itself. In earlier computers a for the hard disk LED wire run to a two-pin connector on the hard disk itself.
- 50. Though this worked fine in case of single hard disk but becomes problem in case of systems having multiple hard disks.
- 51. To solve this problem, the case LED was madeHard Disk Logic BoardAll modern hard disks contain an intelligent circuit board built in the hard disk unit itself.
- 52. In early hard disks all of the control logic for controlling the hard disk operations was placed into the controller plugged into the PC.
- 53. But with newer drives with advance features and high performance, the placing of control logic on the controllers becomes impractical.
- 54. In addition, with the reduction in the size of electronic components, the hard disk manufacturers move most of the control functions to the drive itself. Hard Disk Logic BoardThe logic board is responsible to control hard disk functions, and as hard disks become faster and more sophisticated; more functions are added to the logic board.
- 55. This results in logic board being designed with support to handle more complicated head technologies faster interfaces, and higher bandwidth data streaming from the disk itself. Hard Disk Integrated CacheAll modern hard disks contain a cache integrated into the hard disk unit itself. This is called hard disk integrated cache or hard disk buffer.
- 56. The purpose of this cache is similar to that of other caches in the computer. This cache temporarily stores the results of recent reads from the disk, and also "pre-fetch" information that is likely to be requested in the near future.
- 57. The use of this cache greatly improves the hard disk performance by reducing the number of accesses to the hard disk.
- 58. Most modern hard disks have internal cache memory of upto 8 MB; although some high-performance SCSI drives have about 16 MB of internal cache.Geometry of Hard Disk Drive The geometry of a hard disk drive is the organization of data on the platters. The geometry of the hard disk drive specifies how and where the data is stored on the surface of each platter. The geometry of the hard disk drive is usually specified by the following numerical values:Heads
- 59. Cylinders
- 61. Write PrecompensationHeadsThe head of a hard disk drive represents the total number of sides on all the platters that store data. For example if a hard disk drive has 8 platters, the hard disk drive can have maximum upto 16 heads. Some hard disk drive manufacturers use a technology called sector translation. As per this technology a hard disk drive can have more than two heads per platter. Therefore as per sector translation, it is possible that a hard disk drive can have 12 heads on only one platter. However, irrespective of technology used for manufacturing hard disk drive, the maximum number of heads a hard disk drive can contain is 16.
- 62. CylinderAll the data on a hard disk drive is stored on concentric circles on the surface of each head.
- 63. Each concentric circle is called track.
- 64. A set of all tracks of same diameter present on a head is called a cylinder. It is the number of cylinders that is used for measuring the drive geometry and not the number of tracks.
- 65. The number of cylinders in a drive and the number of tracks on a platter in a drive are exactly same.
- 66. The number of cylinders affects the storage capacity of the hard disk drive. The more the number of cylinders the more the data can be stored on the hard disk. Sectors Per TrackMost hard disks subdivide the tracks into small arcs called sectors. Each sector can hold 512 bytes of data. BIOS limitations set the number of sectors per track at 63. Collection of sectors is cluster as OS make these cluster to keep track of sectors. Depending upon file system we have different size of Clusters. It might be 1K cluster or 64K cluster.Chkdsk Command can tell the size of cluster.
- 67. Formatted using 1024 byte cluster
- 68. Formatted using 4096 byte cluster
- 69. MBR- Master Boot RecordThe first sector of the Hard Disk. - Usually only 512 bytes.Contains: - Table of primary partitions - Disk Signatures - Directions for starting the operating system.
- 70. Write PrecompensationIn the older hard disks, each sector contains the same number of tracks.The sectors present on the outside of a platter are physically longer than those closer to the center. Because of this difference in sizes of the sector make it difficult for the hard disk to write on sectors especially on the inner sectors.The older hard disks require some kind of adjustment while writing to the inner sectors. This adjustment is called Write Precompensation.
- 72. Landing ZoneThe earlier hard disks are highly prone to damage when the machine is switched off. As soon as the computer is switched off, the platters of the hard disk stop spinning, and the airflow that keeps the heads flying stops.
- 73. This head will then land on the disk drive. However there is a possibility that the head lands on a cylinder that already contains data. This may result in disk damage.
- 74. To avoid this situation an unused cylinder number is specified in the BIOS settings where the heads will land when the machine is switched off. This value is called the landing zone.Hard Disk Drive TypesA modern PC uses one or more of the following hard disks:PATA- Parallel Advanced Technology Attachment - Formally known as (ATA).ATAPI – AT attachment with Packet Interface.IDE- Integrated Drive Electronics. - Western Digital original standard.SCSI – Small Computer System Interface.SATA – Serial Advanced Technology Attachment.
- 75. Identifying IDE Data Bus
- 76. Identifying SATA Hard Disk Drive Data Bus
- 77. Identifying Floppy Disk Drive Data Bus
- 78. SCSI Hard DiskSCSI (often pronounced as “scuzzy”) stands for “Small Computer System Interface”. SCSI hard disks are generally used in servers and high-end workstations because of the following advantages:SCSI (often pronounced as “scuzzy”) stands for “Small Computer System Interface”. SCSI hard disks are generally used in servers and high-end workstations because of the following advantages:Improved performance over IDE and SATA in multitasking, multi-user environments.The ability to daisy-chain many drives on one computer
- 79. SCSI
- 80. SCSI
- 81. Serial ATA (SATA) Hard DiskSerial ATA (SATA) is the latest technology that is introduced to replace parallel IDE/ATA. SATA has several advantages over PATA, which are: Superior cabling and connectors Higher bandwidthGreater reliability
- 82. Question/Answer1. Which of the following types of portable media offers the LARGEST storage capacity?A. DVD-DLB. CD-RWC. CD-RD. DVD-RAnswer: A
- 83. Question/Answer