What would I lose if I needed to reinstall from a Time Machine backup?

Question

Is there a list somewhere of the areas of the hard drive that aren't backed up by Time Machine? And does reinstalling from Time Machine install everything from the backup or just parts of it?

I like to tweak things a lot, like customizing the system Apache server and installing stuff into /usr/local (Max Howell's Homebrew, for instance), so I'd like to double check what areas I might lose if I needed to reinstall from a Time Machine backup (whole disk image backups seem a bit overboard for my tastes).

Answer 1

Things which they were not restored and they were crucial, was:

• MySQL Databases
• VMWare Fusion virtual machines

The default backup exclusion list, can be found in:

/System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.plist

Do not forget to check your excluding folders on the prefs as well ;)

Answer 2

Time machine backups most things I (and others) have done an upgrade of the OS ie to a new disk from a TM backup. I have also done a restore after my hard disk died.

To see what it does not backup go to System Preferences -> Time Machine->Options. I forget the defaults but they include various caches - e.g. ~/Library/Caches. I have added ~/.Trash

You can also see what it has backed up by looking at /Volumes//Backups.backupdb//Latest

Answer 3

I don't think that you'll end up loosing anything (except few temporary files). This is covered here:

• What can Time Machine back up, and where can it put it’s backups?
• What should I exclude, and what should I not exclude?

The information is from the Podini Time Machine page (I highly recommend reading), which is one of the best collection of information about Time Machine on the web.

I used Time Machine to upgrade my disk (backup, then boot off the installation dvd and restore a time machine backup on the new one) and did not loose /opt, /usr/local and other.

Answer 4

You might loose lower level stuff in /usr/local when reinstalling using a Time Machine backup.

I know from my own experience that Macports does not get restored (installed in /opt/local).