Information Technology Reference
In-Depth Information
as the Entourage database and virtual machine disk images: every
time any file inside changes, the whole file changes, forcing Time
Machine to back up the entire image again. That's not a big deal if
the image is small, but if it's in the range of hundreds of megabytes
or larger, it'll cause problems with Time Machine.
So you should add such files to the Exclude These Items from
Backups list, but see the sidebar
(Sparse) Bundles of Joy
, shortly
ahead, for a potential way to have your cake and eat it too.
•
Your CrashPlan backup:
If you use CrashPlan to store
secondary backups offsite, you might also use it to back up someone
else's computer to your disk. Other users' files are stored, by default,
in
/Library/Application Support/CrashPlan/backupArchives
. (You
can set a different location by going to CrashPlan's Settings tab
and then, in the Backup view, clicking the Configure button by
“Inbound backup from other computers” and then clicking the
backup destination at the bottom.) Whichever folder you use, you
should exclude it from Time Machine if you want to avoid creating
another copy of the other user's backup files (taking up valuable
room on your Time Machine disk in the process).
•
TechTool Pro's directory backups:
A popular disk utility called
TechTool Pro can optionally store backups of your disk's directory
to help you recover from disk errors. But these files can be
quite
large, and because they change all the time, Time Machine shouldn't
back them up. They're located in
~/Library/Application Support/
TechTool Protection
; if you use Tech Tool Pro, I suggest excluding
that entire folder from Time Machine.
Beyond the items just listed, you might in some cases want to think
about whether to exclude the following:
•
System files:
The files that make up Mac OS X—the contents of
your
/System
and
/Library
folders, various invisible files and folders
at the main level of your hard disk, and the applications included
with Mac OS X, such as Mail and Safari—are all included by default
in a Time Machine backup. That's a good thing, as it enables Time
Machine to restore your whole system, or any part of it. However,
