Will Time Machine delete files already on my external HD?

Question

The title pretty much sums it up.  I have a 3TB HD and I use it for saving render files and raw video footage, but now I need to use it for Time Machine too.  If I use it for TM, will all of my files alredy on the HD disappear, or stay put?  One more thing... If I need to partition the external HD and use the new partition for TM, can I still restore my computer from that partition?  Any help will be gladly accepted!

Answer 1

Yes, that's an OK solution for what you need to do. In fact, if you can partition off just enough space for all the files on your hard drive, then you can just clone to the newly made volume. Much faster than a Time Machine backup.
To resize the drive do the following:
1. Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
After the main menu appears select Disk Utility and click on the Continue button. Select the hard drive's main entry then click on the Partition tab in the DU main window.
2. You should see the graphical sizing window showing the existing partitions. A portion may appear as a blue rectangle representing the used space on a partition.
3. In the lower right corner of the sizing rectangle for each partition is a resizing gadget. Select it with the mouse and move the bottom of the rectangle upwards until you have reduced the existing partition enough to create the desired new volume's size. The space below the resized partition will appear gray. Click on the Apply button and wait until the process has completed.  (Note: You can only make a partition smaller in order to create new free space.)
4. Click on the [+] button below the sizing window to add a new partition in the gray space you freed up. Give the new volume a name, if you wish, then click on the Apply button. Wait until the process has completed.
You should now have a new volume on the drive.
Clone Lion using Restore Option of Disk Utility
Boot to the Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Select Disk Utility from the main menu then press the Continue button
Select the destination volume from the left side list.
Click on the Restore tab in the DU main window.
Check the box labeled Erase destination.
Select the destination volume from the left side list and drag it to the Destination entry field.
Select the source volume from the left side list and drag it to the Source entry field.
Double-check you got it right, then click on the Restore button.
Destination means the new external backup volume. Source means the internal startup drive.