1. A+ Guide to Software Managing, Maintaining and Troubleshooting THIRD EDITION Chapter 10 Supporting Hard Drives

2. 2A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

4. 4A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

6. 6A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

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

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

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

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

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

13. 13A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

14. 14A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

15. 15A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Disk Compression in Windows XP and Windows 2000 (continued) 1. Open Windows Explorer 2. Right-click the volume to be compressed 3. Select Properties from shortcut menu 4. On the General tab, check Compress drive to save disk space, click OK 5. Select whether to compress entire volume, click OK To compress an NTFS volume:

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

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

18. 18A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

19. 19A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Disk Caching (continued) 1. The CPU asks for data from hard drive 2. Hard drive controller reads data from the drive and sends it to the CPU 3. CPU requests more data, often data that immediately follows previous data 4. Hard drive controller reads data from the drive and sends it to the CPU

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

21. 21A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

22. 22A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

23. 23A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

25. 25A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

27. 27A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

28. 28A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

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

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

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

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

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

35. 35A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Windows 9x Backup Utility 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 Msbackup.exe can be used to back up to removable disks and tape drives

36. 36A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

37. 37A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

38. 38A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

39. 39A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

40. 40A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

41. 41A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Where Viruses Hide Virus 1. Incubation period 2. Contagious 3. Destructive Types  Boot sector virus  File viruses (macro viruses)  Multipartite viruses

42. 42A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

43. 43A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

45. 45A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

46. 46A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

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

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

49. 49A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

50. 50A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition 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

51. 51A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition How a Virus Replicates

52. 52A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition How a Trojan Horse Gets into Your Computer A Trojan horse is an infestation masquerading as a legitimate program People pass the program around thinking that it’s useful

53. 53A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition How a Worm Gets into Your Computer Most worms come to your computer or network through the Internet Usually through an open port  A firewall is the best defense against worms

54. 54A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Worms Spread Through Open Ports

55. 55A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Virus Hoaxes Warn about a nonexistent virus Useless traffic overloads email systems Check virus hoax Web sites  http://hoaxbusters.ciac.org http://hoaxbusters.ciac.org  http://www.hoaxinfo.com http://www.hoaxinfo.com  http://www.hoaxkill.com http://www.hoaxkill.com  http://www.viruslist.com http://www.viruslist.com  http://www.vmyths.com http://www.vmyths.com

56. 56A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Protecting Against Computer Infestations Make regular backups Use antivirus software regularly Keep Windows current with updates and patches Implement a firewall Use wisdom when managing program

57. 57A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Virus Symptoms A downloaded document contains macros A program takes longer than normal to load The number and length of disk accesses seem excessive for a simple task Many more: see p. 435

58. 58A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition What to Do When You Suspect a Virus Infestation Run a virus scan program to detect and delete the virus Get latest upgrade of AV software or try another AV program Download recent virus definitions Check Web site of the AV software vendor for information

59. 59A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Antivirus Software

60. 60A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Choosing Antivirus Software Can it download new software upgrades and virus definitions from the Internet? Does it automatically execute at startup? Can it detect macros in a word processing document as it is loaded? Does it automatically monitor files being downloaded from Internet, including email? Does it email you about new viruses and updates?

61. 61A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Using Antivirus Software Scan memory and boot sector for viruses each time the PC boots Consider scheduling AV software to run at the same time every day Some AV software can run continuously in the background

62. 62A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Using Antivirus Software (continued) Set your AV software to scan:  Files as they are downloaded from the Internet or a network  Documents for macro viruses each time a document is opened by a word processor  Both files and boot sectors of hard drives and disks

63. 63A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Troubleshooting Hard Drives Determine main priority and focus on it  Data  Software  Hardware Resources  Documentation  Manufacturer’s Web site  Technical support from ROM BIOS, hardware, and software manufacturers

64. 64A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Troubleshooting Hard Drives with Third-Party Software Norton Utilities  Easy-to-use tools to prevent damage to hard drive, recover data from damaged hard drive, and improve system performance PartitionMagic  Manages partitions on a hard drive more quickly and easily than Fdisk or Disk Management SpinRite  Can recover data from a failing hard drive when other software fails

65. 65A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Software Problems with Hard Drives Root cause is often a virus  Corrupted OS files  Corrupted partition table, boot record, or root directory, making all hard drive data inaccessible  Corruption of area of the FAT that points to the data, data’s directory table, or sector markings where data is located  Corrupted data

66. 66A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Resolving Hard Drive and Data Access Problems Partition table Boot record FAT and root directory System files Data and program files

67. 67A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Data and Program File Corruption To restore a data file that is not backed up  Use OS tools and commands  Use third-party software  Use a professional data recovery service

68. 68A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Data and Program File Corruption (continued) If a file has been accidentally erased or the disk is otherwise damaged  Don’t write anything to the disk  For a floppy, use DOS Diskcopy, Copy Disk in Windows Explorer, or third-party program

69. 69A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Data and Program File Corruption (continued) Problems with files and the file system  Corrupted file header – read the file as a text file to recover the contents  Lost clusters – Chkdsk or ScanDisk turn lost clusters into files in the root directory  Erased file – look in the Recycle Bin, try the Unerase or Undelete command

70. 70A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Summary Supporting hard drives and making backups Viruses and other computer infestations, and how to protect against them Troubleshooting hard drives

71. 71A+ Guide to Software: Managing, Maintaining and Troubleshooting, Third Edition Homework Read chapter 10 of text Read pp. 575-586 of text - Linux