Gathering Information
Your most powerful tool in troubleshooting is
your ability to ask smart, probing questions. Good probing
questions can center around the description of the equipment being
used and the steps to reproduce the issue.
The first thing you
should find out is: What exactly is the problem? Getting a clear
picture of what is not working is crucial if you want to find the
solution. Try to get as complete and specific a picture as possible
about what problems are occurring, when they occur, and what error
messages are displayed. Search the Knowledge Base if you think this
might be a common problem.
Identifying the Problem
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Start with open-ended questions such as "What
is the issue?" or "What is happening onscreen?" Open-ended
questions generally start with words like how, why, when, who, what, and where. They can't be answered by yes or no.
You usually gather more information this way, even if some of it is
not exactly pertinent to the problem at hand.
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2.
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Let the user explain uninterrupted and in
their own words what they have experienced. The explanation may
help you avoid assumptions about the source of the problem, because
you may hear that more things are broken than you expected.
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3.
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As you begin to understand the basics of the
problem, start using closed-ended questions that require more
limited, specific answers. "What version of the operating system
are you using?" and "Is there an icon on your Desktop?" are closed
questions. The user can either tell you the version or tell you
that he or she doesn't know (in which case, you would guide the
user to the information). Closed-ended questions often can be
answered by yes, no, or a value such as "10.4."
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4.
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Verify your
understanding of what the user has told you. Restate what you have
been told and get the user's agreement that you understand the
problem. An example of restatement would be, "Okay, so what's
happening is that when you do X, Y happens. Is that correct?"
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5.
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If the user agrees that you understand,
continue to gather information. If the user does not agree that you
understand, clarify what you misstated and again verify your
understanding. Do not continue with troubleshooting until the user
agrees that you understand the problem.
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Asking Helpful Questions
Here are some questions to ask a user before you
continue to troubleshoot:
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What are the problems and symptoms?
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What were you (the user) doing when the problem
occurred? (Very useful when you try to reproduce the problem.)
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Has this feature or functionality ever worked?
(Is the user trying to burn DVDs in a Combo drive?)
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What exact system hardware, Mac OS version, and
exact versions of software are involved? (Important when you try to
reproduce the problem, and later when you verify the repair.
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Was any hardware or software recently added or
removed?
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Are there environmental considerations? (Is the
computer close to a heater, window, or an electrical device?)
Sometimes, just looking at menus or standard
dialogs gives you important information. For example, the quickest
way to check for basic network connectivity is to check the Network
Status pane in Network preferences. You don't need to begin your
troubleshooting by restarting all of your company's network routers
or calling your network administrator to complain about
connectivity.
Using Tools and Techniques to Gather
Information
When you are gathering information, three useful
resources are System Profiler, which provides information about the
current state of your computer, Apple Remote Desktop, which helps
you to gather information from remote computers, and Mac OS X logs,
which serve as a chronological diary of everything that has
happened on your computer.
System Profiler
Use System Profiler (/Applications/Utilities) to
gather information about your computer's current state and
configuration. System Profiler gets its main information from the
device tree that Open Firmware builds at startup time, but it
updates dynamically when plug-and-play bus devices are connected,
so FireWire and USB devices will appear in System Profiler even if
they are connected after startup. Unlike many other applications or
utilities, System Profiler does not use a preference file (.plist),
so its behavior cannot be corrupted by invalid or corrupted
preferences.
Use System Profiler for situations where the
operating system, or an application running on it, refuses to
recognize hardware that is known to be connected to the system. You
can also run System Profiler after booting from the Mac OS X
Install DVD, or from a remote computer over the network.
System Profiler provides information about the
configuration of the system, including the computer type and speed,
the version of firmware, the version of Mac OS running, the amount
of memory installed, and the types of network connections.
If you need to gather information remotely, you
can use tools like Apple Remote Desktop or log in to the other
computer via ssh and run System Profiler from the command
line. If it's not appropriate for you to directly manipulate the
other computer, you can have the user run System Profiler, save the
generated report, and email it to you. If you don't have access to
a Mac OS X computer, the user can export the report in a plain-text
or rich-text format.
Apple Remote Desktop
Apple Remote Desktop is a real-time screen
sharing and desktop management tool that allows system
administrators to configure remote systems, distribute software,
and provide direct assistance. With the Apple Remote Desktop
administration software, you could access your office computer from
home as if you were sitting at your office computer. In a
classroom, Apple Remote Desktop enhances the learning experience by
allowing the instructor to monitor and control students' computers.
In a corporate environment, it provides a solution for managing
remote systems, reducing administration costs and increasing
productivity.
The client for Apple Remote Desktop is included
with Mac OS X 10.4 and can be enabled from the Services pane in
Sharing preferences. The Apple Remote Desktop administration
software can be purchased separately.
You can also use third-party tools that provide
some of the functionality of Apple Remote Desktop. Virtual network
computing (VNC) programs like Chicken of the VNC can provide this
functionality.
Mac OS X Logs
You can use the Console utility
(/Applications/Utilities) to view log files on a Mac OS X computer.
To do so, open Console and click Logs in the toolbar to display a
list of available logs in the Logs list at the left. To view the
contents of a log, select the log in the list. Console displays the
contents of the log in the Contents pane at the right. If you
prefer to view log files using the command line, or with another
program, the log files for Mac OS X are stored in /var/log,
/Library/Logs, and ~/Library/Logs.
For installer errors, look in the installer log
(install.log) under /var/log in the Logs pane. Among other things,
this log lists the files that were copied, any errors, and the
installed partition. If you suspect there have been Software Update
errors, look in the Software Update log under /Library/Logs. For
application and system process errors, look in console.log. To view
system messages in Console, click system.log. Console
updates its log display dynamically as events take place.
To simplify viewing particular logs, the File
menu in Console has commands to open console.log and system.log, as
well as an "Open Quickly" submenu you can use to navigate directly
to a particular log. The logs are identical regardless of the
method you use to view them.
When using Console, you can either manually note
the date and time on the last entry, or click Mark in the toolbar
to add a time marker after the last entry. You can then look at
actions that occur after that date and time. When commands execute
in Mac OS X, messages appear in Console. Typically, the first part
of a system message gives you the date and time stamp. The next
part names the owner of the process. After that, you see the
process and the process ID. After the process ID, you see the
actual error or message. In this example, the only information is a
repeat of the date, showing that the iCal helper will relaunch in
an hour.
2005-04-28 14:48:48.906 iCal Helper[516] Launch of helper planned at : 04/28/05 15:48:48
Log viewing is most helpful when there is no
apparent error in the user interface, and you cannot figure out why
an application is no longer working. In that case, Console might
show you an error message that will direct your trouble
shooting.
Verbose Mode
If you encounter a problem during the startup of
Mac OS X, you can use verbose mode to gather information. To use
verbose mode, press Command-V when you hear the startup chime.
Verbose mode shows what's happening in the startup process in a
command-line interface. The startup sequence will stop if there is
a problem, and you may be able to see the items or processes that
are involved with the problem.
Messages during startup are stored in the
system.log file. Any kmod destroy messages that you see in
the verbose mode are harmless. These are simply indications that
Mac OS X is unloading kernel modifications that do not apply to
your particular platform.
MORE INFO
Refer to Knowledge Base document 106388, "Mac OS
X: How to Start up in Single-User or Verbose Mode."
Problem ScenarioGather
Information
It's important to be thorough in the
information-gathering stage. Users tend to notice only the parts of
the problem that affect them directly. As a result, they don't
always provide a complete or accurate description of the
problem.
Here's an example. A user says that she can no
longer access the Internet from home. She's using an AirPort Base
Station and a DSL modem. She says she hasn't made any changes to
her settings and she has a strong AirPort signal. Her DSL modem
status lights indicate that she has a DSL connection.
As you gather information, you ask if there are
other wireless networks in range. Checking the AirPort menu extra,
you see that there are a number of wireless networks (she lives in
an apartment). You notice that the network she has joined is called
"linksys." This strongly suggests that the network she's on is
provided by a Linksys wireless router. When you ask her about it,
she mentions that it is not the name of her AirPort Base Station.
She reveals that a few days before, she had inadvertently unplugged
her AirPort Base Station. She hadn't realized it was unplugged
because her Internet connection continued to work fine. When she
discovered it was unplugged, she plugged it back in, but still
can't connect.
When her AirPort Base Station was unplugged, her
computer joined another wireless network. The base station that
provided services to the new network also gave her an IP address,
so she continued to have Internet access. Now it appears that the
owner of that network is restricting the distribution of IP
addresses, so her Internet access seemed to disappear without her
intervention. Switching back to her AirPort network, now that it is
properly plugged in, restored her Internet service.
If you hadn't asked for details about how it was
working, you probably would not have discovered that she was using
the wrong wireless network until you had spent a significant amount
of time troubleshooting her network settings.
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