Backup iPhone to external drive on Mac What is the best technique for changing the backup location of one's iPhone to an external drive. It would seem that with small SSD's (256GB) and very large iOS devices (128GB) that Apple would easily enable this. 

I found the below answer, but asking a non-techie friend to create a sym link is really not ideal.

http://ismashphone.com/2012/05/how-to-change-the-location-of-your-iphone-backup.html


  If you have any number of iOS devices, you likely back your stuff up
  onto your computer. Perhaps iCloud, but after a certain point, you may
  have so much stuff to back up that it’s best to just put it all on
  your computer than it is to pay for the additional iCloud storage.
  That’s especially the case if you have multiple iOS devices. You can
  save a lot of space on your drive if you have lots of iOS apps, etc.
  For instance, we were able to free up 100GB, no joke.
  
  OS X
  
  1) Make sure that iTunes is closed.
  
  2) You will now move your folder called ~/Library/Application
  Support/MobileSync/Backup/ to the drive you want to back up to. For
  instance, an external drive or secondary drive within your computer.
  Whichever works for you.
  
  3) Launch Terminal Applications/Utilities/Terminal and type in the
  following command line:

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

  
  In the above example, ‘DriveName’ would be the name of the new backup
  location.
Ok I FINALLY got this to work!! The alias solution mentioned above actually really helped. I tweaked the process slightly and looked at other references to get this to work.  I'm using a WD My Cloud NAS drive to store iOS backups. Heres' what I did, step by step: 


Create a new folder on the WD external drive and name it 'Backup'
Opened the Terminal app and typed in the following line: 


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

*Be sure to use the name of your external hard drive where I've used the WD My Cloud drive.

What this ended up doing was to create a brand new Alias folder of the 'Backup' folder that I created on the WD MY cloud drive (alias folders have the arrow on them meaning they point elsewhere. In my case to the WD drive). It created this new Alias folder within the original 'Backup' folder on my computer. This is the new folder that I want iTunes to back up my iOS devices to, as it sends all the data to my external hard drive without taking up space on my computer. A few more steps to get this finalized


Now since the Alias folder resides within the original 'Backup' folder on my computer, we need to remove it from there and bring it up one level to be at the same level as the original backup folder. Before moving it, we need to rename the original 'Backup' folder to something like 'Backup_Old'. 
So this is what things look like now: Library > Application Support > MobileSync > Backup_Old > Backup (this is the Alias folder with the arrow).  Now all we have to do is move the 'Backup' folder up to the same level and we're good to go!


Test it out by backing up your device through iTunes and you'll notice that the Alias folder on your computer takes up like 4kb while, the contents inside actually take up a whole lot more. Also to verify, check the folder on your external hard drive and it should be fairly large. 

I used this site to help with the terminal syntax part: http://support.digidna.net/hc/en-us/articles/203504123-Storing-your-iPhone-Backups-on-an-Alternate-Location