HARD DISK DRIVE (HDD)

STORAGE DEVICESOne of the widely used Hardware for Storing Permanent Data is HARD DISK DRIVEIt is used for Storing of DATA for long term use.

Hard Disk DriveIntroductionHard Disk Drive is a nonvolatile data storage device, it means that the storage device retains the data even when no power is supplied to the computer.Some of the profound changes in PC hard disk storage are its capacity, data transfer rates from the media.

Topic 4 - Hard drive InterfaceIntegrated Drive Electronics (IDE)/EIDE

It is used to attach Mass Storage media devices to the computer. The next generations of IDE interface is Enhanced IDE (EIDE)

Small Computer System Interface (SCSI) It is capable of supporting up to 7 to 15 devices.Serial ATA (SATA) It is an internal or inside-the-box interface technology. External SATA is commonly known as ESATA. USB It is an External , pocket Harddisk

Topic 1 - Features Storage Capacity The storage capacity of the hard disk refers to the amount of disk space that can be used to store the user data.

Data Transfer Speed There are two ways to measure the speed of the disk drive Average seek time Transfer rate

Stability It has been measured by Mean Time Between Failure (MTBF).

TYPES OF HDD

Hard Drive ControllersIDE (aka parallel ATA)EIDESCSISATA

IDE HARD DISK DRIVEIDE Hard Disk is a 40 Pin Connector Hard Disk and is Connected to IDE connector on Motherboard

Motherboard ConnectionsOnboard Controllers(2 x 40 pin male ports)Primary IDE controller is usually faster ATA/66, 100 or 133. Secondary controlleroperates at ATA/33Normally, the IDE controllersIdentified as IDE1 and IDE2on the motherboard

INTERNAL PARTS OF THE HDD

INTERNAL PARTSPLATTERSPINDLE MOTORHEAD ACTUATORACTUATORREAD/WRITE HEADLOGIC BOARDCONNECTORPOWER SUPPLY CONNECTOROUTCASING BOX

Hard Disk Drive Components A flat, round disk called platters is used in a hard disk The platters are loaded on a spindle. Spindle motor spins the platters. Electromagnetic read/write devices called heads are mounted onto sliders. Each platter has two heads

Topic 3 - Hard Disk Drive Components Platters

This platter is made up of substrate material, which gives structure and rigidity

Platters are physically connected in the middle and driven by the spindle motor.

Hard Disk Read/Write Heads

The hard disk drive read/write heads act like an interface between the magnetic media and the part of the hard disk.

Heads are joined to the head actuator move across the disk.

Hard Disk Drive Components Types of Read or Write Heads Ferrite Head It is used for magnetic recording.Metal in Gap Head (MIG) - A metal substance has been filled in the gap, and increases the resistance of magnetic saturation. Thin Film Head - This head floats closer to the disk than the other heads. Magneto Resistive Head - The MR head can change resistance.

Hard Disk Drive Components Giant Magneto Resistive Head (GMR) - It will work on multilayer of materials dumped in it.Head Actuator Mechanism Stepper motor actuators It is an electrical motor that can step from location to other, with click-stop positions Voice Coil Actuator It is used to shift the head arms in and out . It has a special guidance system

Hard Disk Drive Components Spindle Assemble The spindle motors are directly connected to the hard disk platter spindle

Spindle MotorThe motor that spins the platters is called the spindle motor.

Logic Board (s) The logic boards have electronics that control the drives spindle and head actuator systems.

PLATTERPLATTER IS A METALIC PLATE WHICH IS USED TO STORE THE DATA IN THE ELECTROMAGNETIC FORM.THE DATA IS SAVED IN TRACK,SECTOR & CLUSTER FORMATTHERE CAN BE MORE THAN ONE PLATTER IN A HARD DISK

SPINDLE MOTORSPINDLE MOTOR is used to revolve the Platter to access the each and every part of the HARD DISKThe revolving of the platter is measured in RPM (RPM stands for REVOLUTION PER MIN/ROTATIONS PER MIN)Current RPM ranges from 7,200 to 15,000

ACTUATORACTUATOR is used to make access the Read Write Head to the every corner of the PlatterIf we consider the live example for the Actuator, it is like a CAR WIPER which moves in 45 degree approximately

READ AND WRITE HEADRead Write Head often refereed as R/WHEADIt is a Small Black Device which is responsible for the Operation of Reading and Writing.It is used for Reading and Writing operations from the HARD DISK

READ AND WRITE PROCESSPlatters are divided into 512 byte sectors. These sectors are the area on the platter that data is written to. The platters have a magnetic coating applied to them that is extremely sensitive to magnetism.

LOGIC BOARDIT is a Circuit Board which is used to send the signals and logical operations related to HARD DISK

WORKINGWhile the platters are rotating in a circle, the read/write heads are moved over the disk surface to the location where they need to write (or save) information. The read/write heads do not actually touch the surface of the disk platters; instead, they hover about ten micro-inches (or millionths of an inch) abovethats not even enough space to place a hair between the read/write head and the platters surface. This design helps improve disk performance, because a read/write head that made contact with the platter would cause friction, slowing down the rotation speed of the disk.

Hard Drive ControllerHard DriveControllerExternal Data BusIn IDE hard drives, the contoller circuitry is built into the driveThe controller allows the hard drive to send/receive data using the external data bus

THE STORAGE MEATHODTHE DATA IS STORED IN THE FORM OF TRACKS SECTOR AND CLUSTERS

TRACKSJust as there are grooves, or tracks, on a record or music CD, there are also tracks on each platter. These tracks are evenly spaced across the platters surface.

SECTORSThe platter is divided into pie slices, thus dividing the tracks into 512-byte sectors. Sectors are the actual storage areas for data, and each has an address that is made up of the platter side number, the track number, and the sector number on that track.

SECTOR

CLUSTERSA group of any number of sectors can make up a cluster. When a partition is formatted, the file system will determine the cluster size based off the partition size. For example, a partition that is 2GB in size formatted as FAT will use a 32K-cluster size. That same 2GB partition formatted as FAT32 will use only a 4K-cluster size.

Geometry of Hard Drive Cylinders It is a set of all platters. Heads It is used to read data from the hard disk drives disk plattersSectors per Track A track is a one ring of data on single side Tracks are divided into many sectors. Write pre-compensation Used to adjust the smaller tracks

Geometry of Hard Drive Landing-ZoneWhen the system is turned off, the BIOS should send the heads of hard disk to the cylinder where there is no data.

Modes Three methods available for data addressingCHS (Cylinder Head Sector) LBA (Logical Block Address)ECHS (Extended Cylinder Head Sector)

MOUNTING A DRIVE IN CABINET

Connecting an IDE drive40-pin IDE ribbon cableRed line aligned with pin 14 prong Molex Connector

IDE CablesRibbonRoundedNo twist!40 pin 40 pin/80 wires Max speed = 33Mb/secMax speed = 133Mb/sec

40 wire IDE ribbon cable33 Mb/sec max80 wire IDE ribbon cable133Mb/sec max

SATA Cable7 pin connector4-wire data cableMotherboard SATA socket

BASIC CONNECTION

IDE1 and IDE2 at Startup

PATA DesignPrimary IDE ChannelSecondary IDE ChannelMasterSlaveMasterSlaveMax of 133 Mb/secMax of 133 Mb/sec

SATA DesignSATA ControllerDrive 4Drive 1Drive 2Drive 3150 Mb/sec150 Mb/sec150 Mb/sec150 Mb/sec

MASTER/SLAVE SETTINGS

MASTER/SLAVE

SSD A solid-state drive (SSD) (also known as a solid-state disk[1][2][3] though it contains no actual disk, nor a drive motor to spin a disk) is a data storage device that uses integrated circuit assemblies as memory to store data persistently. SSD technology uses electronic interfaces compatible with traditional block input/output (I/O) hard disk drives, thus permitting simple replacement in common applications.[4] Additionally, new I/O interfaces, like SATA Express, have been designed to address specific requirements of the SSD technology.

Configuring a Hard Disk Connect data cable and power cablePower up PC, enter BIOSStandard CMOS settingsAuto detect or enter CHS valuesCreate partitionsFormat each driveInstall O.S.

Hard Drive PartitioningWhat is it?Primary PartitionExtended PartitionLogical Drives

PartitionsPrimary PartitionDrive Letter = c:Set to ActiveStores O.S.Extended PartitionLogicalDrive 1LogicalDrive 2Primary PartitionHard DiskDrive Letter = d:Drive Letter = e:

Partition FactsA maximum of 4 primary partitions per diskUp to 24 logical drives per diskEach partition must be formattedA PC must have at least 1 primary partitionThe primary partition is where the O.S. is storedExtra partitions are optional

Disk Management

File System The file system decides the manner in which data is accurately arranged on a hard disk drive. The main function of the FAT is to give the mapping between clusters and the physical location of data in terms of cylinders, tracks, and sectors. FAT 12 FAT 16FAT 32NTFS

Windows File SystemsFile System is created when you format the drive. The types areFAT 16FAT 32NTFSFormatting also creates the boot record, the root directory, the File Allocation Table and the data area

FAT 16File Allocation Table 16-bitA max of 216 = 65,536 addressable sectorsMax partition capacity of 65,536 x 512 = 33MbDoes not support disks larger than 2.1 GbUsed up to Win95 release 11.44 Mb floppy disks, zip disks and USB memory sticks are formatted using FAT

FAT 32

File Allocation Table 32 bitA max of 232 = 4 billion addressable sectorsGrouped 4 512 byte sectors together = a cluster1 cluster = 2048 bytes or 2KbMax hard disk size = 2 TbMax partition size of (4 billion x 512 bytes) = 32GbAllows for up to 24 logical drivesWindows 95 release 2 onwardsNo mechanism for file security

NTFSNew Technology File System64 bit file systemWindows NT, 2000, XPMain Advantage = Security (encryption)Supports partition sizes up to 2048 Gb or 2Tb

Data Organization in Hard Disk The data is recorded on the magnetic tracks of a hard disk drive. Each track is divided into number of sectors. Data is pressed on each sector. Microcomputers hard disk drives are following the soft sector format. In the latest soft sector format, the track number, head number and sector number is written on each sectors ID field.

Data Read and Write Operation Hard disk heads convert electrical signals to magnetic signals and magnetic signals to electrical signals.

By using encoding method, the stored data has been recorded onto the hard disk.

This encoding method translates zeros and ones into patterns of magnetic flux reversals.

Topic 7 - Hard Disk Drive Configuration Cable (Data and Power) Power Cable Interface Cable

Jumper Settings (Master/ Slave/ Cable Select) They are sets of pins with caps placed in various arrangements.In some drives manufacturers have cryptic MS, SL, CS initials

BIOS settingsThe BIOS made after 1996 will support a drive larger than 4GB.

Hard Disk Drive Configuration IO Address Devices use memory location for interfacing with the computer.A typical hard disk controller uses 1F0-1F7h I/O port. Interrupt Request Line (IRQ)It permits a hardware device to look inside the computer.When the device need attention, IRQ makes direct line to the microprocessor

DMA Channel Without CPU interference, the DMA controller transfers data from a drive to the computers memory.

Hard Disk Drive Setup Low level formatting The disks tracks are divided into a specific number of sectors.LLF is most important for the proper operation of the drive.

Partitioning The hard disk drive can support separate file systems by creating a partition on a hard disk drive.

High level formatting The operating system marks the structures essential for managing files . High-level formatting is the creation of a table of contents for the disk

Hard Disk Drive Setup FDISK For example: 4 gig hard drives, divided it into 4 partitions. The four independent drives are C, D, E, and F. 'C' partition = 2 Giga Bytes 'D' partition = 1 Giga Bytes'E' partition = 500MB'F' partition = 500MB

Sector Organization Cluster Grouping sectors into larger blocks are called clusters . Master Boot Record (MBR) The location of the master boot record is cylinder 0, head 0, and sector 1. DOS Boot Record (DBR) In the beginning of the boot drive the DOS boot record will load . Boot Sector The two tasks of boot sector is to load in the operating system and to inform the user information about the disk.

Sector Organization File Allocation TableThe FAT has entry for each cluster, which describes how the file has been used, and which files are free for use.

Root Directory FAT file system uses root directory to format disk.

Data Area The content of the files are stored in data area.

Common Errors & Troubleshooting

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