Hard Disk Storage A hard disk drive contains rigid, disk- shaped platters, usually constructed of...
-
Upload
daniel-richards -
Category
Documents
-
view
212 -
download
0
Transcript of Hard Disk Storage A hard disk drive contains rigid, disk- shaped platters, usually constructed of...
Hard Disk Storage
A hard disk drive contains rigid, disk-shaped platters, usually constructed of aluminum or glass
Also known as a Fixed DiskGrown rapidly in size and
performance and have dropped dramatically in price over recent years
Hard Disk Drive Operation
consists of spinning disks with heads that move over the disks and store data in tracks and sectors
heads read and write data in concentric rings called tracks, which are divided up into segments called sectors
Hard Drive Anatomy
Disk platters
Logic board
Read/write heads and Spindle motor
Cables and connectors
Head actuator mechanism
Configuration items (such as jumpers or switches)
S.M.A.R.T
Stands for Self-Monitoring, Analysis and Reporting Technology
Industry standard providing failure prediction for disk drives
According to Seagate, 60% of drive failures are mechanical, which are exactly the type of failures S.M.A.R.T. is designed to predict.
Caching
Has a major effect on disk drive performance
Can be software (Smartdrv in DOS or Vcache in Windows)
Can be hardware Many IDE and SCSI drives have
cache memory built directly into the drive’s on-board controller
The IDE Interface
A generic term applied to any drive with an integrated (built-in) disk controller
The IDE interface as we know it is officially called ATA (AT Attachment) and is an ANSI standard
Placing the controller on the drive gives IDE drives an inherent reliability advantage over interfaces with separate controllers
IDE Controllers
Many people who use systems with IDE connectors on the motherboard believe that a hard disk controller is built into their motherboard. It’s actually part of the drive
The IDE connector on motherboards in many systems is nothing more than a stripped-down bus slot
IDE Bus Versions
XT IDE (8-bit ISA) AT Attachment (ATA) IDE (16-bit
ISA)MCA IDE (16-bit Micro ChannelOnly the ATA version is used today
ATA Standards
ATA-1ATA-2 ATA-3ATA-4 (ATAPI)ATA-5 (ATAPI)
The SCSI Interface
Stands for Small Computer System Interface
General purpose interface used for connecting many types of devices to a PC
Many PC manufacturers have standardized SCSI for high-end systems (fast, up to 160Mb per second!)
SCSI Standards
Standard SCSIFast SCSIFast-20(Ultra)Fast-40(Ultra2)Fast-80(Ultra3)
Termination
Improper termination still is one of the most common problems in SCSI installations
Three popular types of termination Passive
Active (also called Alternative 2)
Forced Perfect Termination
SCSI Drive Configuration
More complicated than IDE drivesNeed to set SCSI ID setting and
Terminate any open resistors Most SCSI host adapters are factory-
set to ID 7 or 15
Setting the ID usually involves changing jumpers on the drive
SCSI Versus IDE
IDE drives usually cost less than SCSI drives (popular for home or budget PCs)
SCSI allows for smoother multitasking and increased overall data throughput (popular for high end workstations or servers