[.Neo]

I set Time Machine up to make automated backups of my Home folder (with the exception of Downloads and the Desktop). Lately it takes for ever to make the hourly backups. In System Preferences it just stays stuck on "Preparing..." and you can see two circling arrows behind the HD icon in the Finder. Beyond that there's no actual disc activity when it comes tot the external HD for a very long time. Hell, after a while the drive shuts down entirely and goes into sleep mode with Time Machine still showing "Preparing...".

Is there anything I can do to fix this / speed things up?

[Simon]

How long have you let it 'prepare'? I've seen it take as long as 40 min to get passed 'Preparing...'. Fortunately that only happened once though.

[.Neo]

Hour or so. But that can't be normal as it used to be much faster (max. 10 minutes or so).

[.Neo]

I just did this:

1) Turn Time Machine off
2) Trash the com.apple.TimeMachine.plist in /Library/Preferences
3) Restart
4) Full Spotlight reindex of the Macintosh HD
5) Added a bunch of folders to the "Do Not Backup" list in Time Machine
6) Turn Time Machine on

Currently Time Machine is doing hourly backups in a matter of minutes again, instead of staying stuck on "Preparing..." for over 40 minutes. I just hope it stays that way because I really don't feel like going through this every month...