No. In Lion DU will erase the destination volume prior to Restoring. What is it you want to accomplish? Why do you want a "completely defragmented volume?" Or do you wish to restore backed up files but not erase what is currently on the destination volume?
If you can provide more explicit information on what you are trying to accomplish, then I may be able to give you specific suggestions.
BTW, I was also once an Amiga user.
Thanks Kappy for that very fast reply!
This might sound paranoid but I really want this because of disk defragmentation. I know that OS X handles that automatically for files < 20MB but I have a lot of large files and I can hear my hard drive scratching I created a full backup of my system partition and restored it afterwards once in a while to achieve this. Believe it or not, you really feel a difference after doing that! My harddrive is much less noisy and loading of large files is much faster. Sad its gone.
Amiga... a friend of mine (Atari user) just said something true: Doesn't matter what computer you use as long as the menu bar is on top of the screen
If you need to defragment your drive, then the safest and fastest way to do so is:
1. Get an empty external hard drive and clone your internal drive to the external one.
2. Boot from the external hard drive.
3. Erase the internal hard drive.
4. Restore the external clone to the internal hard drive.
Clone the internal drive to the external drive
1. Open Disk Utility from the Utilities folder.
2. Select the destination volume from the left side list.
3. Click on the Restore tab in the DU main window.
4. Check the box labeled Erase destination.
5. Select the destination volume from the left side list and drag it to the Destination entry field.
6. Select the source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.
Destination means the external backup drive. Source means the internal startup drive.
Restart the computer and after the chime press and hold down the OPTION key until the boot manager appears. Select the icon for the external drive and click on the downward pointing arrow button.
After startup do the following:
Erase internal hard drive
1. Open Disk Utility in your Utilities folder.
2. After DU loads select your internal hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area. If it does not say "Verified" then the drive is failing or has failed and will need replacing. SMART info will not be reported on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Set the format type to Mac OS Extended (Journaled.) Click on the Options button, set the partition scheme to GUID then click on the OK button. Click on the Partition button and wait until the process has completed. Do not quit Disk Utility.
Restore the clone to the internal hard drive
1. Select the destination volume from the left side list.
2. Click on the Restore tab in the DU main window.
3. Check the box labeled Erase destination.
4. Select the destination volume from the left side list and drag it to the Destination entry field.
5. Select the source volume from the left side list and drag it to the Source entry field.
6. Double-check you got it right, then click on the Restore button.
Destination means the internal hard drive. Source means the external startup drive.
Note that the Source and Destination drives are swapped for this last procedure.
Alternatives to the above are using one various defragmentation utilities such as iDefragment or Drive Genius. But these utilities have to move data around on the drive resulting in slower times plus the greater risk of file corruption or disk directory corruption. The above method gives the same result - a fully defragmented drive plus a backup to boot.
4. Check the box labeled Erase destination.
That's my problem. This box doesn't exist anymore. Also, my external drive is 250GB and my internal is 1TB with 146GB in use. DU tells me that there is not enough space left for a restore. So I guess it does a block-copy and I would end up with a restored but still fragmented drive.
Yes, it disappeared in Lion and Snow Leopard 10.6.8. That's because Apple has realized the need to erase a destination before doing a disk restore. This should be automatic. I believe that DU only does block copy when the source and destination are either the same capacity or the destination has a greater capacity than the source.