3.4
Document What You Do
As you try to solve your computer problems, keep notes
about what you do and the outcomes of these actions.
This can be a valuable reference for you later and can be
extremely helpful if you need to talk to a technical support
representative. Knowing exactly what was done and the
results(includinganyerrormessages)canmakeproblem
solving much easier. In addition, if you have problems at
a later time, you may be able to spot a pattern that would
otherwise elude you.
Recovering Data from Damaged Drives
Files are more likely to be recoverable by TechTool Pro’s
data recovery routines if its automatic Protection features
have been enabled for your volumes. Congure these op-
tions within the TechTool Protection pane of the
System Preferences.
Repairing Drive Problems
You probably already understand how critical the proper
operation of your hard drive is for your computer. It con-
tains the data that allows the computer to boot, as well as
the programs you use and the les you’ve created. Tech-
Tool Pro includes powerful diagnostic and repair routines
to keep your drives functioning correctly.
In most cases, this manual will refer to a drive as a “vol-
ume.” A volume is simply a unit of storage that appears
to the computer as one “logical device.” The terms “hard
drive” and “volume” are almost interchangeable. Although
aharddiskcancontainmorethanonevolume(multiple
partitions), a volume cannot contain more than one hard
drive.(Thisisnotentirelytrue.SomeformsofRAIDdisk
setups can make many drives appear as one volume).
DVDs and CDs may also appear as one or more volumes.
When you view the contents of a volume in the Finder,
you’re not typically seeing everything on the volume.
Every volume contains many invisible les and data les.
This allows the computer to access the data on that par-
ticular volume. Items such as the le catalog or directory,
the extents B-tree, and a host of other objects, dictate
howdataisstoredonaparticulardevice(seetheGlos-
sary section of this manual for denitions of these terms).
These items comprise the “volume structures” of a volume.
In most cases, when a drive fails and then is repaired by a
utility such as TechTool Pro, it is not the physical drive itself
that is being repaired. It is the software that makes up the
volume structures. If there is a problem with the structure
of a volume, it can prevent the computer from being able
to boot or prevent you from having access to your data.
If there is an actual problem with the physical drive, like
an electrical or mechanical problem, software will not be
able to correct the problem. TechTool Pro is unique in that
it can check the mechanical and electronic aspects of a
drive, as well as repair the volume structures.
To check for disk problems, run the Surface Scan test, the
SMARTcheck(ifapplicable),andtheVolumeStructures
test. These tests do a thorough check of the drive hard-