So Time Machine is a pretty convenient way to backup your machine, and I use it to backup my laptop to an external FireWire drive. Although Time Machine backs up the "whole system," I assumed there had to be some exclusions, such as cache files or /dev, for example. After a short bit of digging, I discovered that these paths are specified in a standard property list at
The full list is some 57 items, and is available below. Besides the expected cache items, the list includes some items I thought interesting:
/home */Library/Logs /Users/Guest /Library/Safari/Icons.db /.Spotlight-V100
Of these, the only one I find odd is the exclusion of logs. If your system goes haywire such that you restore it completely from a backup, it might be nice to see what went wrong.
[Update] Fixed the path to the StdExclusions.plist file.
The contents of these paths are excluded, but the directories themselves are preserved as they are required for a successful restore.
/Volumes /Network /automount /.vol /tmp /cores /private/tmp /private/Network /private/tftpboot /private/var/automount /private/var/run /private/var/tmp /private/var/vm /private/var/db/dhcpclient /private/var/db/fseventsd /Library/Caches /Library/Logs /System/Library/Caches /System/Library/Extensions/Caches
These directories and their contents are excluded completely.
/.Spotlight-V100 /.Trashes /.fseventsd /.hotfiles.btree /Backups.backupdb /Desktop DB /Desktop DF /Network/Servers /Previous Systems /Users/Shared/SC Info /Users/Guest /dev /home /net /private/var/db/Spotlight /private/var/db/Spotlight-V100
User Paths Excluded
These directories and their contents are excluded per-user. The path is relative to the user's home folder.
Library/Application Support/MobileSync Library/Application Support/SyncServices Library/Caches Library/Logs Library/Mail/Envelope Index Library/Mail/AvailableFeeds Library/Mirrors Library/PubSub/Database Library/PubSub/Downloads Library/PubSub/Feeds Library/Safari/Icons.db Library/Safari/HistoryIndex.sk