a+ certification guide
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A+ Certification Guide. Chapter 12 Storage Devices. Chapter 12 Objectives. Drive Interface Types Hard Disk Drives SSD / Flash Drives Identify External Removable Storage RAID Optical Drives Floppy Drives Tape Drives Troubleshooting Storage. Storage Principles. - PowerPoint PPT PresentationTRANSCRIPT
A+ Certification Guide
Chapter 12
Storage Devices
Chapter 12Objectives
Drive Interface Types Hard Disk Drives SSD / Flash Drives Identify External Removable Storage RAID Optical Drives Floppy Drives Tape Drives Troubleshooting Storage
Storage Principles
Data storage uses a file table:– An index to the filenames
Data storage can be– Internal– Externally attached– Accessed remotely
Storage devices can become unreliable:– All mechanical devices eventually fail.– Redundant data storage is essential.
External/Internal Drive InterfacesInterface Location Interface
Speeds Drive Types Supported
eSATA
External
1.5Gbps
3Gbps
6Gbps
Hard disk drives
IEEE 1394a (FireWire 400) 400Mbps
Hard disk drives, optical drives, tape backups
IEEE 1394b (FireWire 800) 800Mbps
Hard disk drives, optical drives, tape backups
Fast Ethernet External (Network)
100MbpsHard disk drives for network access
Gigabit Ethernet 1000Mbps
USB 2.0External
480MbpsHard disk drives, flash memory, card readers, floppy drives, optical drives
USB 3.0 5Gbps Hard disk drives, SSD, flash memory, card readers, floppy drives, optical drives
SATA1*
Internal
1.5GbpsHard disk drives, optical (DVD, BD media) drives, RAID arrays, SSD
Can be converted to eSATA via header cable
SATA2* 3.0Gbps Hard drives, optical (DVD, BD media) drives, RAID arrays, SSD, Can be converted to eSATA via header cable
SATA3* 6.0GbpsHard drives, RAID arrays, SSD
Backwards compatible with SATA1, SATA2
Data Storage Connectors
PATA and SATA Drives
PATA—Parallel Advanced Technology Attachment:– Derived from ATAPI/IDE (Integrated Drive Electronics).– Data bits are sent in parallel using 40-pin ribbon wire.
• Drive jumper positions can also determine role.– Color of ribbon wire connector determines drive role.
• Roles are Primary/Master and Secondary/Slave.• 80-wire ribbons offer “cable select” option for role.
– Drive uses a five-pin Molex power connector. SATA—Serial Advanced Technology Attachment:
– L-shaped power cable.– Data cable has only seven wires (much easier on airflow).– Use one drive per adapter port.
• No jumper blocks needed.
Hard Disk Power and Data Cables
Hard Disk Drive (HDD)
Used to store the operating system. Made of circular metal oxide-coated platters:
– Coating can be magnetically charged to create small areas called fluxes.
• Direction of the flux makes it a binary 1 or 0.
Platters divided into tracks (concentric circles). Each circle is divided into sectors (like pieces of a pie). Each sector hold 512 bytes of data (4,096 fluxes):
– Sectors x tracks x 512 = drive capacity
Two types of drives in current use:– PATA—Also called ATA/IDE – on older motherboards– SATA—Currently most popular
Characteristics of Hard Drives
Spin Rate– Higher spin rate = faster data access
Buffer Size– Memory cache for recently accessed files– Ranges from 8MB–64MB
Hybrid features– Solid State memory combined with normal platter
based storage– SLC memory is faster
Hard Drive Installation
BIOS configuration (after physical installation)– PATA:
• Can usually default to auto-detect.• If not hard drive parameters must be calculated and
configured in BIOS under Hard Drive (HDD) settings.
– SATA:• If necessary, enable the SATA host adapter.
– Shut down after saving BIOS settings.• Connect SATA drive and restart system.
– Enter BIOS and verify SATA drive detection. At this point, the drive can be formatted for data storage/OS
installation.
SATA Installation
Enabling SATA in BIOS
PATA Drive Performance
Select correct PIO or DMA transfer mode in BIOS. Select the correct block mode in the BIOS. Install bus mastering Windows drivers.
– Bypasses the CPU for data transfers to RAM. Enable DMA/UDMA mode in Windows.
– Verify that drive, cable, and adapter are compatible. Adjust disk cache software settings.
Most of these performance enhancements are done automatically by either the BIOS or the OS.
Removable Storage Types:
– USB 1.0/ 2.0/3.0 (flash memory and external hard disks)– Parallel port– SCSI– ATAPI– IEEE 1394a–FireWire (some external hard disks)
Tape Drives:– Native (uncompressed)– Compressed– Usually use SCSI interfaces– Often come with automated backup software
Flash Memory:– Many types
Flash Memory Formats
Flash Memory Reader Slots
Figure 12-19
12fig19
SSD Memory Drive USB Adapter
Redundant Array of Independent Disks (RAID)
RAID types of most interest: RAID 0—Two drives with striping.
– No redundancy; only good for performance. RAID 1—Two mirrored/duplexed drives.
– Data redundancy; small decrease in performance. RAID 5—Minimum of three drives with striping.
– Data redundancy; increase in performance.– Equivalent of one drive required for redundancy
calculations (parity function). RAID 10 (or 0+1)—Needs four drives.
– Better redundancy than RAID 0; better performance than RAID 1.
RAID Configuration Must have a motherboard that supports one of the RAID types. When changing to a RAID system, existing data will likely be lost.
Back it up. Sizing for RAID 5:
– For maximum benefit, all drives should be of similar size.• The smallest drive determines the capacity.• Capacity equals smallest drive x number of drives minus
the capacity of the smallest drive (for parity).– Parity is the math calculation performed on the drives
that allows a single drive to fail and still recover the data.
– Example, RAID 5, 3 drives: 40GB, 60GB, 60GB drives:» Storage capacity is (3 x 40) – 40 = 80 GB
– A RAID drive is treated as a single drive after it is configured.
CD/DVD Optical Drive Optical Drive Types:
– Compact Disc (capacity 650MB–870MB)• CD–ROM• CD–Recordable (CD-R) (one-time recordable)• CD–Rewritable (CD-RW)• Mini Disc (capacity 185MB–210 MB)
– Digital Video Disc (capacity 4.7GB–17GB)• DVD–ROM• DVD Rewritable (DVD-RW) • DVD Rewritable +R/RW• DVD Rewritable–R/RW• DVD-RAM
– Blu-ray – 25-50GB capacity Data is created by laser light etching the surface to create
indentations/pits. – Lands are the space between pits.– A binary “1” is a change from a pit to a land or vice versa.
Optical Media Installation/Configuration
Internal CD/DVD:– CD is usually PATA or ATAPI (same thing).– DVD can be PATA or SATA interface.
External CD/DVD:– Typically use USB 2.0.
Installation:– Plug ‘n’ play is normally sufficient for basic operation.– Manufacturer-based drivers optimize capability.
Issues:– Disc compatibility:
• CD-R versus CD-RW versus CD+R/RW versus CD–R/RW.• DVD RW versus DVD-RAM, and so forth.
– Driver limitations—May prevent playback on any machine other than the one it was recorded on.
Choosing File Systems for CD/DVD
Live File System:– Drag and drop file recording.– File greater than 2GB supported.– Cannot be used on many stock consumer CD/DVD
players found in homes and autos. Mastered:
– Can be read by most consumer media systems.– Limit of 2GB of files can be recorded.
Floppy Disk Drives
Yes, they are still in use. 1.44Mb capacity most common. Connects to motherboard with 34-pin cable.
– Has a twist in the cable.– Red stripe on side with pin 1.
4-wire miniature jack. Write-enabled slider—for protecting data from
accidental erasure. Use IRQ 6/address 3F0–3F7h.
Have largely been replaced by USB memory.
Remote Storage
Network Attached Storage:– Independent appliance connected to network– Managed remotely using HTML web page– Used in small to medium-sized businesses and
residences Storage Area Networks:
– High-speed storage system– Redundant arrays (RAID 3, 4, 5, 10)– Fiber-optic connections– Used in industrial high-end data systems
Troubleshooting Storage
Sources of problems: Power cable Data cable
– Incompatible cable connectors– Jumpers not set for Primary/Master or Secondary/Slave
BIOS configuration problems Drive defects
– Drive heads misaligned– Mechanisms jammed– Drive motor failure
Trouble Symptoms
Read/write failure– Look for physical damage, overheating.
Slow performance– Check cable type, BIOS configuration.
Loud clicking noise indicates drive imminent failure Failure to boot –Check BIOS settings, connections.
Drive not recognized: Check BIOS settings, connections.
OS not found: Check for MBR, boot sequence on multi OS.
RAID not found: Check BIOS and data cables.
RAID stops working: Check for drive failure.
Troubleshooting CD/DVD Devices
Can’t write to media? Check for– Incompatible media:
• CD-R versus CD-RW versus CD +R/RW, and so on.– Closed media (indicates not enough space):
• Enable multiple sessions.– Packet-writing problems:
• Rewritable media can be particular about format.– DVDs are especially difficult across platforms.
» PC versus Consumer DVD playback systems.– Media problems:
• Damage from sunlight, heat sources, or scratches to surface.– Incorrect insertion of media.
Troubleshooting CD/DVD Devices
Types of Problems:– The program doesn't detect the drive.– The program doesn't list the drive as a target drive for writing
files.– When installing the program, it indicates that no compatible CD
or DVD drives were found.– The program detects the drive but displays an error message
when trying to write files to the drive.
Quick Solutions:– Double-check for correctly installed cable connections.– Update drivers/software support files from the drive
manufacturer.– Update third-party software; verify that the drive is supported.
Disk Drive Tools
Windows– Chkdsk– Format/Fdisk
Manufacturer provided Hard Disk Diagnostics– Western Digital– Hitachi
Data Recovery/Third-Party tools– SpinRite– Partition Magic– Linux Live – Knoppix Linux Live
What Have You Learned?
– What is an advantage of a SATA drive?– What is the standard sector size on a hard disk
drive?– What types of connectors can be used with an
external hard disk?– What problems can be expected from a DVD
recorded on the PC when playing back on the DVD connected to your television?
– Why might the installation of Linux in a dual-boot configuration cause problems for the Windows OS?
Chapter 12 Summary
Drive Interface Types Hard Disk Drives SSD / Flash Drives Identify External Removable Storage. RAID Optical Drives Floppy Drives Tape Drives Troubleshooting Storage.
Next Lesson: Chapter 13