Dec 18, '07 07:30:02AM • Contributed by: marco.trive
I love Time Machine, but I still think it's incomplete. I'd love to be able to back up different stuff to different disks: this way, when I'm home I could back up the whole system on my large 500GB external drive (as I use a PowerBook), and when I'm on the road, I could back up only some relevant folders on my external 30GB hard disk. With Time Machine, you can back up to different disks, but you can't back up different stuff to different disks.
Before reading on, please understand that the following might be dangerous to your data: please back up on a different disk before proceding. I am not responsible for any data loss you might encouter; this hint has only been tested by me! You should also know that this hint causes (I still don't know why) the deletion of the data contained in the folder /.fseventsd/. I thought this would cause a big mess, but everything seems to work fine so far.
With those warnings in mind, read on for my solution...
Let's say you have two disks: BigDisk and SmallDisk. And let's suppose that you want to back up the whole system to BigDisk, and only some really important folders on SmallDisk. Connect BigDisk and set Time Machine to use it. I went for manual backups, but I don't think this changes anything), then back up (with Time Machine off, to start a backup, you have to right-click on Time Machine icon and select Backup Now). When you're done, unplug BigDisk and go to /Library/Preferences.
Copy the com.apple.TimeMachine.plist file to a safe place and name it com.apple.TimeMachine.BigDisk. Plug in your LittleDisk, and set up Time Machine, excluding all the folders you think are of no vital importance. Once again, I selected manual backups and I started a backup. When it finished, I copied the com.apple.TimeMachine.plist file (it has changed now!) to a safe place and named it com.apple.TimeMachine.LittleDisk.
Now let's say you want to back up again to BigDisk. Here's what you need to do:
- Close the Time Machine preferences pane!
- Unplug LittleDisk and plug in BigDisk
- Copy com.apple.TimeMachine.BigDisk and rename the copy to com.apple.TimeMachine.plist
- Replace /Library/Preferences/com.apple.TimeMachine.plist with the file you just created
- Open the Time Machine preferences pane, select "Choose another disk," and select BigDisk (and again, I selected manual backups)
[robg adds: As I understand it, fsevents is what lets Time Machine do what it does -- it keeps track of all filesystem changes in real time. However, I don't the importance of that directory and its contents.]
