Changing iPhone backup location When I try to follow the procedure laid out in Backup iPhone to external drive on Mac and run

ln -s /Volumes/DriveName/Backup/ ~/Library/Application\ Support/MobileSync/Backup


to change the backup location for my iPad and iPhone terminal tells me that the file directory doesn't exist... what am I missing?
You need to replace the DriveName part with the name of your external drive. One way to find the name is to run

ls -l /Volumes


in Terminal.