An exploration of some of the Macintosh OS X troubleshooting myths. Originally presented to the Boston Macintosh Users Group (BMAC) on December 10, 2008

2. Macintosh Myths
Troubleshooting voodoo,
popular misconceptions
& downright lies
presented by
Jeff Berg & Al Willis

4. Sources

5. WIZARDS, NINJAS & GURUS

6. WIZARDS, NINJAS & GURUS
Myth My friend is a computer guru and he told me…

7. WIZARDS, NINJAS & GURUS
Myth My friend is a computer guru and he told me…
FACT There are Gurus, and then there are gurus
—what’s your definition?
• Anyone who’s one chapter ahead of me
• Mainframe sysadmin (who doesn’t touch Macs)
• Guy from out of town with a blog

8. WIZARDS, NINJAS & GURUS
Myth My friend is a computer guru and he told me…
FACT There are Gurus, and then there are gurus
—what’s your definition?
• Anyone who’s one chapter ahead of me
• Mainframe sysadmin (who doesn’t touch Macs)
• Guy from out of town with a blog
FACT Even true experts have biases and
objectives.

9. MACINTOUCH SAYS…

10. MACINTOUCH SAYS…
Myth I read it on Macintouch (or on Apple’s Forums,or
at…) say…, so it must be true!

11. MACINTOUCH SAYS…
Myth I read it on Macintouch (or on Apple’s Forums,or
at…) say…, so it must be true!
FACT Macintouch and other forums provide access
to useful information but are also sources of
outdated memes and misunderstood concepts. Be
skeptical about what you believe and pass along.

12. MACINTOUCH SAYS…
Myth I read it on Macintouch (or on Apple’s Forums,or
at…) say…, so it must be true!
FACT Macintouch and other forums provide access
to useful information but are also sources of
outdated memes and misunderstood concepts. Be
skeptical about what you believe and pass along.
FACT Nobody believes their system could be the
cause of a problem—it must be a bug!

13. MACINTOUCH SAYS…

14. MACINTOUCH SAYS…
Myth There are 20 posts on Macintouch saying… so it
must be a major issue! (Why isn’t Apple doing anything
about it?)

15. MACINTOUCH SAYS…
Myth There are 20 posts on Macintouch saying… so it
must be a major issue! (Why isn’t Apple doing anything
about it?)
FACT Satisfied customers don’t post in proportion
to those having issues so the number of users
actually experiencing a given problem is often
exaggerated on forums. Again, be cautious before
jumping to conclusions and spreading false memes.

16. ACCORDING TO MACFIXIT

17. ACCORDING TO MACFIXIT
Myth MacFixIt is always a reliable source

18. ACCORDING TO MACFIXIT
Myth MacFixIt is always a reliable source
FACT While there is some good information
there, be wary of MacFixIt’s fear mongering and
advocacy of Franken-solutions

19. ACCORDING TO MACFIXIT
Myth MacFixIt is always a reliable source
FACT While there is some good information
there, be wary of MacFixIt’s fear mongering and
advocacy of Franken-solutions
Mac Daily Journal: The Despicable MacFixIt
http://www.macjournals.com/news/despicable.html

20. Classics

21. ZAP THE “PRAM”

22. ZAP THE “PRAM”
Myth Restarting with CMD-OPT-P-R will fix it.

23. ZAP THE “PRAM”
Myth Restarting with CMD-OPT-P-R will fix it.
FACT This was more often true prior to OS X
which stores most of it’s parameters in Plists, not
Parameter RAM (or NVRAM for open firmware
computers). Most issues won’t be magically
repaired by zapping PRAM.

24. ZAP THE “PRAM”
Myth Restarting with CMD-OPT-P-R will fix it.
FACT This was more often true prior to OS X
which stores most of it’s parameters in Plists, not
Parameter RAM (or NVRAM for open firmware
computers). Most issues won’t be magically
repaired by zapping PRAM.
Mac OS X: What's stored in PRAM
support.apple.com/kb/HT1242

25. REBUILD THE DESKTOP

26. REBUILD THE DESKTOP
Myth Then a “CMD-OPT” restart must fix it.

27. REBUILD THE DESKTOP
Myth Then a “CMD-OPT” restart must fix it.
FACT In the “Classic” OS, the desktop database
was a special invisible file containing associations
between icons and file types. Your OS X desktop is
a regular directory within your home folder with no
special features.

28. REBUILD THE DESKTOP

29. REBUILD THE DESKTOP
However the OS X Launch Services Database
“records all of the pertinent information about
applications and the kinds of document files and
URLs they are capable of opening. […] Launch
Services can then use this information to determine
the preferred application for opening a given
document file or URL.”

30. REBUILD THE DESKTOP

31. REBUILD THE DESKTOP
Apple Launch Services Programming Guide:
Launch Services Database
http://developer.apple.com/DOCUMENTATION/
Carbon/Conceptual/LaunchServicesConcepts/
LSCConcepts/chapter_2_section_4.html

32. REBUILD THE DESKTOP
Apple Launch Services Programming Guide:
Launch Services Database
http://developer.apple.com/DOCUMENTATION/
Carbon/Conceptual/LaunchServicesConcepts/
LSCConcepts/chapter_2_section_4.html
Google rebuild Launch Services Database for more info

33. PARTITIONING

34. PARTITIONING
Myth I should always partition my system drive.

35. PARTITIONING
Myth I should always partition my system drive.
FACT There are valid reasons for partitioning
hard drives but most reasons for regular users to do
so are based on out-dated notions.

36. PARTITIONING
Myth I should always partition my system drive.
FACT There are valid reasons for partitioning
hard drives but most reasons for regular users to do
so are based on out-dated notions.
FACT If you don’t understand why you’re
partitioning, you probably don’t need to.

37. 10% Solution

38. 10% Solution
Myth I need to leave 10% of my hard disk free or my data
will become corrupt. (Or the OS will freeze.)

39. 10% Solution
Myth I need to leave 10% of my hard disk free or my data
will become corrupt. (Or the OS will freeze.)
FACT It’s true that drives shouldn’t be crammed
to capacity but keeping 10% free on a large data
drive is leaving money on the table.
However you do want to leave free space at least
equivalent to the amount of physical RAM on your
System or swap disk.

40. DEFRAGMENTING A DRIVE

41. DEFRAGMENTING A DRIVE
Myth My machine is running slowly, I should defragment
my hard disk to speed things up.

42. DEFRAGMENTING A DRIVE
Myth My machine is running slowly, I should defragment
my hard disk to speed things up.
FACT Systems running OS X won’t benefit
in most cases. However High-end media captures
to certain types of drives may be more reliable if
the drive is freshly formatted.

43. DEFRAGMENTING A DRIVE
Myth My machine is running slowly, I should defragment
my hard disk to speed things up.
FACT Systems running OS X won’t benefit
in most cases. However High-end media captures
to certain types of drives may be more reliable if
the drive is freshly formatted.
www.kernelthread.com/mac/apme/fragmentation/

44. BATTERIES

45. BATTERIES
Myth Never charge a partially discharged battery because it
will develop a memory.

46. BATTERIES
Myth Never charge a partially discharged battery because it
will develop a memory.
Myth Never run a battery down completely it will kill it.

47. BATTERIES
Myth Never charge a partially discharged battery because it
will develop a memory.
Myth Never run a battery down completely it will kill it.
FACT Battery chemistry has improved and proper
care and feeding differs from that of older batteries

48. BATTERIES
Myth Never charge a partially discharged battery because it
will develop a memory.
Myth Never run a battery down completely it will kill it.
FACT Battery chemistry has improved and proper
care and feeding differs from that of older batteries
www.apple.com/batteries/

49. Apothecary

50. ANTI-VIRUS SOFTWARE

51. ANTI-VIRUS SOFTWARE
Myth I need to install anti-virus software to be safe.

52. ANTI-VIRUS SOFTWARE
Myth I need to install anti-virus software to be safe.
FACT At this time there is no significant risk of a
computer virus infecting OS X

53. ANTI-VIRUS SOFTWARE
Myth I need to install anti-virus software to be safe.
FACT At this time there is no significant risk of a
computer virus infecting OS X
FACT Anti-Virus software can have a negative
impact on your systems performance.

54. ANTI-VIRUS SOFTWARE

55. ANTI-VIRUS SOFTWARE
Myth Apple just released a tech note suggesting that I install
anti-virus software

56. ANTI-VIRUS SOFTWARE
Myth Apple just released a tech note suggesting that I install
anti-virus software
FACT “We have removed the KnowledgeBase article because it
was old and inaccurate. The Mac is designed with built-in
technologies that provide protection against malicious software
and security threats right out of the box. However, since no
system can be 100% immune from every threat, running anti-
virus software may offer additional protection.”
Apple spokesman Bill Evans to TidBITS.

57. ANTI-VIRUS SOFTWARE

58. ANTI-VIRUS SOFTWARE
Myth Because there are no known Viruses, Macintosh
computers are completely safe from viruses and intrusions

59. ANTI-VIRUS SOFTWARE
Myth Because there are no known Viruses, Macintosh
computers are completely safe from viruses and intrusions
FACT No computer is completely safe but at this
time Email filtering and safe web browsing are your
best defenses against ‘net nasties.

60. ANTI-VIRUS SOFTWARE
Myth Because there are no known Viruses, Macintosh
computers are completely safe from viruses and intrusions
FACT No computer is completely safe but at this
time Email filtering and safe web browsing are your
best defenses against ‘net nasties.
TidBITS
Should Mac Users Run Antivirus Software?
http://db.tidbits.com/article/9511

61. ANTI-VIRUS SOFTWARE

62. ANTI-VIRUS SOFTWARE
Myth Macs aren’t really safer, it’s just that they’re not
targeted because they represent a small market segment

63. ANTI-VIRUS SOFTWARE
Myth Macs aren’t really safer, it’s just that they’re not
targeted because they represent a small market segment
FACT OS X was built from the ground up to
include strong security and resistance to attack
including Sandboxing,Tagged Downloaded Apps,
Application Signing & Library Randomization

64. ANTI-VIRUS SOFTWARE
Myth Macs aren’t really safer, it’s just that they’re not
targeted because they represent a small market segment
FACT OS X was built from the ground up to
include strong security and resistance to attack
including Sandboxing,Tagged Downloaded Apps,
Application Signing & Library Randomization
www.apple.com/security/

65. Panacean Myth

66. REPAIR PERMISSIONS

67. REPAIR PERMISSIONS
Myth Anytime I have a problem, I should repair
permissions first—it’s like rebuilding the desktop!

68. REPAIR PERMISSIONS
Myth Anytime I have a problem, I should repair
permissions first—it’s like rebuilding the desktop!
FACT You’re reading MacFixIt, aren’t you?
Repairing permissions is no panacea.

69. REPAIR PERMISSIONS
Myth Anytime I have a problem, I should repair
permissions first—it’s like rebuilding the desktop!
FACT You’re reading MacFixIt, aren’t you?
Repairing permissions is no panacea.
“Seriously, Repair Permissions is Voodoo”
daringfireball.net/2006/04/repair_permissions_voodoo

70. REPAIR PERMISSIONS

71. REPAIR PERMISSIONS
Myth Permissions go bad over time

72. REPAIR PERMISSIONS
Myth Permissions go bad over time
FACT Permissions only change if something
changes them. This was more common prior to
10.3—primarily due to poorly written third-party
installers.

73. REPAIR PERMISSIONS
Myth Permissions go bad over time
FACT Permissions only change if something
changes them. This was more common prior to
10.3—primarily due to poorly written third-party
installers.
FACT “Repairing” merely sets the permissions of
certain files to the values specified by a Bill of
Materials (.bom) file within /Library/Receipts

74. REPAIR PERMISSIONS

75. REPAIR PERMISSIONS
Myth Repair permissions before and after any software
update or installation.

76. REPAIR PERMISSIONS
Myth Repair permissions before and after any software
update or installation.
FACT We can thank our friends at MacFixIt (and a
misguided Macintouch contributor) for perpetuating
this meme. Apple does not recommend this.

77. REPAIR PERMISSIONS
Myth Repair permissions before and after any software
update or installation.
FACT We can thank our friends at MacFixIt (and a
misguided Macintouch contributor) for perpetuating
this meme. Apple does not recommend this.
daringfireball.net/2006/04/repair_permissions

78. REPAIR PERMISSIONS

79. REPAIR PERMISSIONS
Myth Apple recommends repairing permissions as a routine
maintenance task.

80. REPAIR PERMISSIONS
Myth Apple recommends repairing permissions as a routine
maintenance task.
FACT No they don’t. The meme might be based
on this KnowledgeBase article:
Mac OS X 10.4 Help:
My computer keeps freezing or I see a flashing question mark
(Note the title. This is a step in repairing a specific
problem not a maintenance task.)

81. REPAIR PERMISSIONS

82. REPAIR PERMISSIONS
Myth I should never repair permissions because Al and Jeff
say it’s voodoo.

83. REPAIR PERMISSIONS
Myth I should never repair permissions because Al and Jeff
say it’s voodoo.
FACT They do say that, but you are encouraged
to repair permissions if you believe a problem
might be the result of a file permissions issue.

84. REPAIR PERMISSIONS
Myth I should never repair permissions because Al and Jeff
say it’s voodoo.
FACT They do say that, but you are encouraged
to repair permissions if you believe a problem
might be the result of a file permissions issue.
Macworld
Repairing permissions: What you need to know
www.macworld.com/article/52220/2006/08/repairpermissions.html

85. Misc. Memes

86. SOFTWARE UPDATE

87. SOFTWARE UPDATE
Myth I never use Software Update because it will corrupt
my system. I always download the full installer from Apple
and run that instead.

88. SOFTWARE UPDATE
Myth I never use Software Update because it will corrupt
my system. I always download the full installer from Apple
and run that instead.
FACT Software update works just fine for most
people most of the time.

89. SOFTWARE UPDATE
Myth I never use Software Update because it will corrupt
my system. I always download the full installer from Apple
and run that instead.
FACT Software update works just fine for most
people most of the time.
However if you have a problem after an update it
can sometimes be repaired by downloading and
running the full installer.

90. Curse of rev 1.0

91. Curse of rev 1.0
Myth Don’t ever buy rev. 1.0 of Apple hardware because it
always has problems.

92. Curse of rev 1.0
Myth Don’t ever buy rev. 1.0 of Apple hardware because it
always has problems.
FACT A Macintouch favorite. Jeff ’s 1.0 iPhone &
TiBook were without major flaws. His “mature”
iMac had serious issues (which Apple repaired—
twice) Make your decision based on your wants,
needs and personal assessment of the risks and
rewards, not a rule-of-thumb.

93. HACKING THE SYSTEM

94. HACKING THE SYSTEM
Myth The new version of xyz.library breaks pdq.app so I
should install the previous version of the library manually.

95. HACKING THE SYSTEM
Myth The new version of xyz.library breaks pdq.app so I
should install the previous version of the library manually.
FACT You still don’t believe what we’re saying
about MacFixIt, do you? While such hacking may in
fact produce a “fix” for your problem, the
“Frankensystem” you create may exhibit other
problems in the long run. Be wary of such “fixes.”

96. RAID

97. RAID
Myth My data is on a RAID so I don’t need a backup.

98. RAID
Myth My data is on a RAID so I don’t need a backup.
FACT RAID is not a backup. Your RAID unit can
be damaged or stolen. The data, even redundantly
written to disk, is still vulnerable.

99. APPLE’S DISK UTILITY

100. APPLE’S DISK UTILITY
Myth Disk Utility sucks. It will make my problems worse.

101. APPLE’S DISK UTILITY
Myth Disk Utility sucks. It will make my problems worse.
FACT Disk Utility is a useful tool and, while it
doesn’t fix every problem, it fixes some things that
other utilities can’t.

102. DISKWARRIOR

103. DISKWARRIOR
Myth DiskWarrior is a last resort because it may cause me
to lose files. I should do X, Y and Z before running it.

104. DISKWARRIOR
Myth DiskWarrior is a last resort because it may cause me
to lose files. I should do X, Y and Z before running it.
FACT DiskWarrior should be one of your first line
tools in tracking down disk/directory related
problems—and is more likely to be effective if used before
you muck with the sick drive. Just be sure that the version
of DW you are using is compatible with version of
the OS you’re running.

105. Solutions

106. WIZARDS, NINJAS & GURUS 2

107. WIZARDS, NINJAS & GURUS 2
Myth I’m just an ordinary user—I need an expert
to troubleshoot these problems.

108. WIZARDS, NINJAS & GURUS 2
Myth I’m just an ordinary user—I need an expert
to troubleshoot these problems.
FACT Most answers are available via Apple’s
KnowledgeBase or via reliable online sources, Take
Control of books, etc.

109. WIZARDS, NINJAS & GURUS 2
Myth I’m just an ordinary user—I need an expert
to troubleshoot these problems.
FACT Most answers are available via Apple’s
KnowledgeBase or via reliable online sources, Take
Control of books, etc.
FACT Most problems can be solved using
common sense and a few simple tools

110. WIZARDS, NINJAS & GURUS 2
Myth I’m just an ordinary user—I need an expert
to troubleshoot these problems.
FACT Most answers are available via Apple’s
KnowledgeBase or via reliable online sources, Take
Control of books, etc.
FACT Most problems can be solved using
common sense and a few simple tools

111. BEST PRACTICES

112. BEST PRACTICES
Don’t panic. Breathe. Make a cup of tea.

113. BEST PRACTICES
Don’t panic. Breathe. Make a cup of tea.
Identify the problem as accurately as possible—hardware? software?
wetware?

114. BEST PRACTICES
Don’t panic. Breathe. Make a cup of tea.
Identify the problem as accurately as possible—hardware? software?
wetware?
Do research online—just try to qualify your source(s)

115. BEST PRACTICES
Don’t panic. Breathe. Make a cup of tea.
Identify the problem as accurately as possible—hardware? software?
wetware?
Do research online—just try to qualify your source(s)
Don’t be afraid to run well-known tools (i.e. Diskwarrior) early
provided they’re up-to-date and likely to solve your problem but
don’t throw tools or fixes at a problem unless there’s good reason to
believe they’re appropriate

116. STOP THE VOODOO!

117. STOP THE VOODOO!
Don’t perpetuate
the myths!

118. Ask the “experts”
or