Using and Configuring Storage Devices Guide to Operating Systems Third Edition.

Using and Configuring Storage Devices

Guide to Operating Systems Third Edition

Guide to Operating Systems, Third Edition 2

Objectives

After reading this chapter and completing the exercises you will be able to:

• Understand basic disk drive interface technologies

• Compare the different types of CD-ROM and DVD storage

• Explain the differences between a storage area network (SAN) and network attached storage (NAS)


Objectives (continued)

• Discuss various removable storage options

• Describe tape drive options and their advantages and disadvantages

• Briefly discuss storage management options in different operating systems


Disk Storage Options

• Briefly discuss various storage technologies

• Most computers arrive with;

– 3.5-inch floppy drive

– high-density floppy or Zip disk

– hard drive

– CD-ROM or DVD drive


Hard Drive Interfaces

• Integrated Drive Electronics (IDE)

– most popular hard drive interface


Hard Drive Interfaces (continued)

• Master

– the first or main drive

• Slave

– secondary storage device



• Three 40-pin header connectors

• Enhanced IDE (EIDE)

– transfer speeds as high as 22 megabits per second

• Small Computer System Interface (SCSI)

– fast interface

– 8 to 16 devices



• Platters, heads, tracks, and sectors per track vary widely from hard disk to hard disk

• EIDE and SCSI provide ways for the controllers to communicate with the disk



• Disk geometry

– information about the hard disk

– configuration

• Storage capacity

– few megabytes to several gigabytes


Basic and Dynamic Disks

• Basic disk

– physical hard drive

– primary partitions, extended partitions, or logical drives

• Dynamic Disks

– volumes that span multiple disks

– fault tolerant disks


RAID Arrays

• Redundant Array of Inexpensive Drives (RAID)

• RAID arrays

– increased reliability

– increased storage capacity

– increased speed


RAID Arrays (continued)

• Different levels of RAID focus on different purposes

• RAID is implemented as a combination of hardware and software


CD-ROM and DVD

• Optical rather than magnetic technology

– compact disc-read only memory (CD-ROM)

– digital versatile disc (DVD)


Compact Disk (CD) Technology

• Use a big “spiral” that starts at the inside of the disk and winds itself to the outside of the disc


Compact Disk (CD) Technology (continued)

• Rotated by a precision motor that keeps the disc speed constant

• Cyclic Redundancy Check (CRC)

– bits encoded in it as other disks do

– error correction bits encoded on the disc


Digital Video Disc (DVD) Technology

• Works like the CD-ROM

• Two sides with up to two layers per side

• Laser light is reflected

• DVD has a spiral that moves from the middle of the disk to the outside like a conventional CD-ROM, but also has a second layer


Recordable and Rewritable CD and DVD

• CD-R and DVD-R

– record data once on the media, and then it can be read many times

– R stands for recordable

• CD-RW and DVD-RW can

– write on the media thousands of times

– RW stands for rewritable


Recordable and Rewritable CD and DVD

(continued)


CD-ROM and DVD-ROM Interfaces

• Connected using a hard disk interface

• EIDE interface with SCSI as a close second

• Drivers for CD-ROM and DVD-ROM built in


Connecting Drives

• Connect as hard disks

– EIDE or SCSI

– USB

– FireWire

• Make sure you have the drivers


Network Storage

• Storage Area Networks (SANs) for– backups

– disaster recovery

– availability of data

• SANs connect servers and storage systems without sending data over the corporate network

• Use Fibre Channel fabric


Network Storage (continued)



• Network Attached Storage (NAS) for– directly attach to a local area network

– work with multiple operating systems

– use LAN rather than a Fibre Channel


Removable Disks and Mobile Storage

• Removable disks are hard disks with a twist

• The first group of drives are those that use flexible magnetic disks such as Zip disks

• The second group consists of drives that use hard platters such as Castlewood’s ORB drives


Removable Large-Capacity Floppy

Drives

• The Zip drive is addressed like a hard disk

– storage capacity of 100 or 750 MB

– external and internal varieties with printer port, SCSI, EIDE, or USB connections


Removable Rigid Cartridges

• Castlewood Systems, Inc. makes the ORB 2.2 GB and the ORB 5.7 GB drives

• The ORB drives come in

– EIDE, SCSI, USB, and FireWire models


Mini USB Drives

• Mini or thumb drives

– use USB port

– Plug and Play

– 64 MB to 1 GB

• Table 6-2 shows storage devices and capacities


Mini USB Drives (continued)


Tape drives

• Used to back up large volumes of data

• Popular for long term storage

• Tape media capacities:


DAT Drives

• Digital Audio Tape drives

– use 4-mm tapes

– digital data storage (DDS) tapes

– DDS-4 capacity 20 Gb (40 Gb compressed)

– backward compatible with other DDS tapes


DLT and SDLT Drives

• Digital Linear Tape drives

– use half-inch wide tapes

– 128 to 208 tracks

– DLT-III tapes are 10 GB (20 GB compressed)

– used in automated tape backup systems


DLT and SDLT Drives (continued)

• Super Digital Linear Tape drives

– magnetic and optical recording methods

– 160 Gb (320 Gb compressed)

– up to 640 Mb (1.28 Tb compressed)

– 1.2 Tb (2.4 Tb compressed) to be released in 2006 or 2007


AIT and S-AIT Drives

• Advanced Intelligent Tape or Super Advanced Intelligent Tape drives

• erasable memory chip in cartridge

• 35/90 Gb to 500 Gb/1.3 TB

• good for 500,000 hours of operation


LTO Drives

• Linear Tape Open drives

• high-end server market

• 100 Gb cartridge with 16 Mbps transfer rate

• 1.6 Tb with 320 Mbps transfer rate planned for future


Windows Removable Storage Options

• Introduced in Windows 2000

• Tracks tapes, CD-ROMs, DVD-ROMs, optical

disks

• Figure 6-6 shows the Removable Storage

section under Computer Management in

Windows 2000


Windows Removable Storage Options (continued)


Storage Management Tools

• OS tools and commands to manage storage

devices

• See the Hands-on Projects for step-by-step

instructions


Windows 2000/XP/Server 2003

• Use Windows Disk Management snap-in tool

– view and manage hard disks

– see Figure 6-7


Windows 2000/XP/Server 2003 (continued)


UNIX/Linux

• Managing, formatting, and partitioning disks

– fdisk

– format

– sfdisk

– cfdisk


UNIX/Linux (continued)

• Mount a file system

– mount

– User Mount Tool


UNIX/Linux (continued)

• GNOME-based Hardware Browser


NetWare 6.x

• Novell Storage Services (NSS)


Mac OS X

• Disk Utility

– repair the disk using the First Aid option

– erase the contents

– partition and format the disk

– set up RAID

– restore a disk image or volume


Mac OS X (continued)


Summary

• Conceptual overview of how operating systems interface with storage devices

• Storage technologies such as hard disk drives, RAID arrays, CD-ROMs, and DVD drives

• Removable storage devices such as Zip disk and ORB drivers


Summary (continued)

• Storage are networks (SANS) and network attached storage (NAS)

• Tape drive options such as DAT, DLT SDLT AIT, S-AIT, and LTO drives


Summary (continued)

• Storage management tools

– disk management

– disk defragmenter

– event viewer

– Performance Logs and Alerts

Using and Configuring Storage Devices Guide to Operating Systems Third Edition.

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