If your Mac hard drive is getting full John Carter has a solution. Consider that you may be filling up one or more of the following folders: Movies -- Pictures -- Documents -- Downloads
John walks us through the steps as follows . . . and we quote:
It is easy to recover a lot of space just by adding an external drive and moving the folders from the internal drive to the external drive, and then creating a symbolic link from the external drive folder back to the internal drive. This could work equally well even if you have a laptop. For laptops, I recommend the Western Digital Passport - whatever size suits you - because they are compact and carry well. An alternative would be to purchase a 3.5" Seagate or Maxtor drive and install it in a 3.5" external case, and this might be cheaper than a Passport drive of the same capacity.
Now for the detail. To move a folder from one location to another, you could simply use Finder to drag the existing folder to an external drive. A preferred alternative (more reliable) would be to use a command line in a Terminal:
$ sudo ditto <source_folder/> <destination_folder/>
Only the contents of the source folder are copied, including all subfolders. If the destination folder does not exist, it will be created, and the contents of the source folder are copied into the destination folder.
$ sudo ditto /Users/jcarter/Movies /VolumesMac1_HD2/Movies
Next, you need to delete the source folder and create a link from the destination folder to where the source folder was. This has to be done in a Terminal:
$ rm -rf /Users/jcarter/Movies
$ ln -s /Volumes/Mac1_HD2/Movies /Users/jcarter/Movies
The symbolic link (specified as symbolic by the -s option) /Users/jcarter/Movies is not a folder. It is a file that pretends to be a folder. When you look at it with the Finder you actually see the contents of /Volumes/Mac1_HD2/Movies. If you use a command in Terminal to look at it you will see:
$ ls /Users/jcarter/Movies
At this point, although not essential, you should log out and log back in. As far as the applications that access the Movies folder are concerned, the folder is still there.
The result is you have just recovered a lot of disc space on your internal drive.
Now, if you did not have the external drive attached and powered up and tried to access something in the Movies folder with, say, iMovie, iMovie will still work but you'll have to specify a new path to work in. Not a good idea, because then you'll have multiple locations for your movies.
If you moved "iPhoto Library" to an external hard drive and the drive was not attached or powered on, iPhoto will ask to you specify a new location for your photos. Again, this is a bad idea because the new location will override the old one and it will appear as though you can't access those old photos. Never fear. You can always tell iPhoto to look in any location for photos at the time you start up iPhoto by holding down the Option key when you launch iPhoto. That brings up the menu to specify the location to look in before bringing up the application. Just be sure you specify an actual iPhoto Library path.
After moving my iPhoto Library to an external drive, I looked at the available paths for iPhoto and discovered the following:
The default location points to the original path:
The next location points to another user login on the Mac:
And, here John closes off with, "May your days be merry and bright."