1 / 70

Chapter 10

Chapter 10. Supporting Hard Drives. You Will Learn…. About supporting hard drives and making backups About viruses and other computer infestations, and how to protect against them How to troubleshoot hard drives. Managing Hard Drives. Keeping the drive clean and free from errors

marjean
Télécharger la présentation

Chapter 10

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 10 Supporting Hard Drives

  2. You Will Learn… • About supporting hard drives and making backups • About viruses and other computer infestations, and how to protect against them • How to troubleshoot hard drives A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  3. Managing Hard Drives • Keeping the drive clean and free from errors • Drive compression • Disk caching • Backups A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  4. Defrag and Windows Defragmenter • Clusters that make up a file are stored together in a chain • Fragmentation occurs when a single file is placed in several clusters that are not directly next to one another • Defragmentation detects and repairs fragmentation A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  5. Windows XP Defragmenter A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  6. Using ScanDisk to Correct Cross-Linked and Lost Clusters • Cross-linked cluster is pointed to by more than one file • Lost cluster (allocation unit) is a cluster that no file in the FAT points to • Chkdsk /F can be used to repair • Windows 9x ScanDisk repairs these problems and others A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  7. Lost and Cross-Linked Clusters A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  8. Windows XP Drive Properties A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  9. ScanDisk Results A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  10. ScanDisk in MS-DOS Mode A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  11. Disk Cleanup • Frees up space • Improves performance A convenient way to delete temporary files on the hard drive A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  12. Disk Cleanup(continued) A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  13. Disk Compression • Helps meet demand for more space on hard drives to hold software and data • Two methods usually used in combination: • Store data on a drive in one big file and manage how data and programs are written to that file • Rewrite data files in mathematically coded format that uses less space A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  14. Disk Compression in Windows 2000 and Windows XP • A file, folder, or an entire volume can be compressed as long as it uses NTFS • A file/folder placed on a compressed volume will automatically be compressed • A compressed file will be decompressed as it is read • Will be recompressed when it is saved back to the compressed volume A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  15. Disk Compression in Windows XP and Windows 2000 (continued) • Open Windows Explorer • Right-click the volume to be compressed • Select Properties from shortcut menu • On the General tab, check Compress drive to save disk space, click OK • Select whether to compress entire volume, click OK To compress an NTFS volume: A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  16. Compressing an NTFS Volume A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  17. Disk Compression in Windows 9x • DriveSpace used by Windows 95 and Windows 98 on a FAT16 file system • Compressed volume is somewhat unstable A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  18. Disk Caching • Temporary storage area in RAM for data being read from or written to a hard drive • Speeds up access to hard drive data • Two kinds • Hardware cache • Software cache A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  19. Disk Caching(continued) • The CPU asks for data from hard drive • Hard drive controller reads data from the drive and sends it to the CPU • CPU requests more data, often data that immediately follows previous data • Hard drive controller reads data from the drive and sends it to the CPU A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  20. Disk Caching(continued) A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  21. Hardware Cache or Software Cache • Hardware Cache • Built right into controller circuit board • BIOS on controller contains cache program • RAM chips on controller hold the cache • Disadvantages • Slower • Upgrading to a faster cache is impractical A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  22. Software Cache • Stored on hard drive like other software • Usually loaded into memory when computer is booted • Uses system RAM to hold the cache • Disadvantage • RAM is used that might otherwise be used for applications software and its data • Advantages • Faster because of where data is stored • Upgrading to a faster cache is practical A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  23. How Disk Caching Methods Have Changed • DOS used buffers to speed disk access • DOS with Windows 3.x used SMARTDrive, a 16-bit, real-mode software disk cache utility • Windows 9x uses VCACHE, a 32-bit, protected mode, built-in caching program • Windows NT/2000/XP uses automated caching as an inherited Windows component A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  24. Enabling Disk Caching in Windows XP A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  25. Making Backups • A backup is an extra copy of data or software that can be used if the original becomes damaged or destroyed • Hardware and software needed • Traditionally involve backup to tape • Full, incremental, and differential backups • Scheduled backups A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  26. The Child, Parent, Grandparent Method A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  27. Full, Incremental, and Differential Backups • Full backup • All data from a hard drive • Incremental backup • Only files that have changed or been created since last backup, whether or not it was a full backup • Differential backup • Files that have changed or have been created since last full backup A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  28. Scheduling Backups • Manual: done by a user sitting at a computer • Automatic: scheduled to run without user interaction • Windows 98 and Windows NT/2000/XP support scheduling any program A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  29. Scheduling Backups(continued) A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  30. Scheduling Backups(continued) A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  31. Scheduling Backups(continued) A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  32. Backup Software • Most tape drives come with backup software • Third-party backup software • Windows backup software A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  33. Windows 2000/XP Backup A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  34. Scheduling a Windows 2000/XP Backup A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  35. Windows 9x Backup Utility Msbackup.exe can be used to back up to removable disks and tape drives • Windows 98 supports backup devices that Windows 95 did not • Use third-party backup software to back up to drives and tapes not supported by Windows 9x A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  36. Disk Cloning Software • Replicates a hard drive to a new computer or to another drive on the same computer • Examples of software • Drive Image by PowerQuest • ImageCast by Innovative Software • Norton Ghost by Symantec Corp Disk cloning, disk imaging, or drive imaging A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  37. Planning for Disaster Recovery • Verify that you can use backup tape or disk to successfully recover the data • Keep records of backups and recovery procedures, including: • Folders or drives backed up • Date of backup • Type of backup • Label identifying tape, disk, or other media A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  38. Viruses and Other Computer Infestations • Infestation • Any unwanted program transmitted to a computer without knowledge of the user • Designed to do varying degrees of damage to data and software; does not damage PC hardware • Categories of infestations • Viruses • Trojan horses • Worms • Logic bombs A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  39. Viruses and Other Computer Infestations (continued) • Virus (most common) • Replicates by attaching itself to other programs • Might simply replicate, might do damage immediately, or might do damage in the future • Worm • Spread copies throughout a network without a host program • Overloads memory or hard drive space by replicating repeatedly A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  40. Viruses and Other Computer Infestations (continued) • Trojan horse • Does not need a host program • Substitutes itself for a legitimate program • Usually cannot replicate • Logic bomb • Dormant code added to software • Triggered by a predetermined time or event A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  41. Where Viruses Hide • Virus • Incubation period • Contagious • Destructive • Types • Boot sector virus • File viruses (macro viruses) • Multipartite viruses A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  42. Boot Sector Virus • Hides in the boot sector program • Hard drive • Master Boot Record program • OS boot record program • Floppy Drive • Boot sector program • Usually spread with a boot floppy • CMOS often protects against this virus A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  43. File Virus • A File virus hides in an executable program or in a document macro • A Macro is a small program contained in a document • Macro viruses are the most common viruses spread by email • Melissa spread around the world in one day A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  44. Multipartite Virus • A combination of boot sector virus and a file virus • Can hide in either type of program A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  45. Cloaking Techniques • Virus signatures are the distinguishing characteristics of a virus • Antivirus (AV) software detects a virus by its signature • Important to update AV software • A Virus attempts to hide from AV software • Changing its signature • Attempting to mask its presence A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  46. Cloaking Techniques(continued) • Viruses are classified by three cloaking techniques: • Polymorphic virus: changes as it replicates • Encrypting virus: transforms into non-replicating program, then reverts • Stealth virus • Masks the size of the file it infests, or • Substitutes an uninfected file when file is opened A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  47. The Damage an InfestationCan Cause • Minor (e.g., altered monitor display) • Major (e.g., erasure of files, or even entire hard drive) • Infestation damage is called the payload A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  48. Results of a Harmless Virus A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  49. How Infestations Spread • Executing email attachments without scanning for viruses • Trading floppy disks containing programs • Connecting a computer to unprotected network • Buying software from unreliable sources • Downloading programs from Internet A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

  50. How Infestations Spread(continued) • Using floppies from unknown sources • Using shared network programs • Using used, preformatted floppy disks • Reading email that automatically runs a word processor to read attachment • Not write-protecting original program disks A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition

More Related