How to back up your iPhone or iPad to an external drive to save space on your Mac

Posted:
in General Discussion edited September 2018
You also should back up iPhones and iPads before upgrading to iOS 12 -- but that can take a big chunk out of your Mac's storage. AppleInsider shows you how to stop clogging up your Mac's drive.




You are backing up your iOS devices to your Mac, right? Since iCloud backups were introduced in iOS 5 in 2011 ago, we were supposedly freed from ever plugging our iPhones into our computers.

Except for how now, seven years later, iCloud still doesn't backup everything. And, it's not what you'd call an instant retrieval if you need to restore.




Really, iCloud backs up data about data. It includes your account details or your app purchase history so that you can later log back in or re-download anything. An iTunes backup copies the apps and everything in them.

If you're helping new or inexperienced iOS users then you know they never think to backup to iTunes on their Mac. You also know that if they do, then the backups themselves can take up a lot of space.

This can be a problem on Macs with limited storage.

What you may not know is that you can do something about that. While still keeping the full backup and still keeping the simplicity of plugging the phone into iTunes, you can move the backup. Put it on an external drive.

What's more, iTunes can automatically backup to that drive and restore from it, too, without you ever doing anything else.

You need a minute in Terminal and a reliable external drive that, preferably, is always connected.

If you're going to do this because you're on a MacBook Pro with very limited SSD space then it will still work. However, there will be the onus on you to always make sure you connect that drive before plugging your iPhone in.

Overview

We're going to physically move the backup from where iTunes defaults to keeping it, over to an external drive. Then, using Terminal we're going to create a symbolic link between these two places.

If you've not had the need to use a symbolic link, you can think of it as a more deeply-rooted alias. Where an alias tells macOS where to find a file or folder, a symbolic link tells it that two places are actually the same.

It's a subtle difference but when you're working with macOS features like iTunes backup, aliases don't have sufficient hooks into the system.

Seek, locate, copy

Create a new folder on your external drive where you want backups to now go. Name it something memorable but do not use spaces. Calling the folder "BackupiPhone" is fine but calling it "Backup iPhone" is not.




Now find where iTunes saves backups now. In the Finder, choose the Go menu, then select Go to Folder or just press Command-Shift-G. In the dropdown dialog that appears, type this:
~/Library/Application Support/MobileSync/
There's probably just one folder in there and it will be called Backup. If you use backup apps like iMazing, though, you can have other things in this folder but they will be clearly named. Choose the folder called Backup and copy it to the new folder on your external hard drive.

Wait until that copy is completed and then if you're brave, delete the original Backup folder. If you're less brave and more sensible, rename it to something like "OLD Backup". Something where you can see what it was and what it needs to be renamed to if you ever want to undo all of this.


Symlink

Make sure iTunes isn't running. Then launch Terminal and type the following with the usual care. In our case, the external drive we've chosen is called Sierra and the folder we created is called BackupiPhone. Remember that we've now copied the original Backup folder into that. This makes the command we need to type be:
ln -s /Volumes/Sierra/BackupiPhone/Backup/ ~/Library/Application\ Support/MobileSync
Type that, hit return and when you get the prompt back, quit Terminal.




The original Backup folder will now again contain something called Backup but it will be a symbolic link. It will have an alias-like arrow at bottom left and if you double-click on it, what opens is the Backup folder on your external drive.

Into action

You're done -- but you need to know that you're good to go for the future. Plug your iOS device into iTunes, click on the iPhone or iPad icon and look at the Summary page.

In there you'll find a section for backups and the heading Automatically Back Up with options for iCloud or This Computer. Make sure This Computer is selected and then click on the Back Up Now button.




After a moment, iTunes will start backing up. There will be nothing new in the original Backup folder but there will in the one on your external drive.

Specifically, in the Backup folder on that drive, there will be a new folder named with some string of letters but also timestamped right now.

That's where iTunes is now backing up your iPhone and it will always do so until you undo all of this. To undo it, you delete the symbolic link in the original Backup folder. The next time you backup via iTunes, it will go back to saving in there.

You could also copy back the latest Backup folder from your external drive but we'd recommend treating that as a safety copy in case something goes wrong. When the phone is correctly and fully backed up to its original iTunes folder, then you can delete it.

One more thing

This is very specifically a solution to how you can lose a huge amount of space to backups. It's also a solution to making a safety copy on a drive that you can remove later but it's not the best or easiest answer for that.

To just know that you've got a full backup of your iOS device on an external drive, you can use a utility such as Hazel or Keyboard Maestro to do timed copies.

Lowest prices on external drives

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Portable external drives

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Comments

  • Reply 1 of 45
    Thanks! 

    Replacing my time machine ext. Hdd , will do this at the same time! 

    Btw.. if I store the back up in the Mac, would time machine have the backup of a backup again? 

    baconstang
  • Reply 2 of 45
    entropysentropys Posts: 1,698member
    Could this can be done wirelessly on a NAS? Ultimate would be without having to turn on the Mac.  I wonder if there is an app for that?
    edited August 2018
  • Reply 3 of 45
    "If you're helping new or inexperienced iOS users then you know they never think to backup to iTunes on their Mac." It's a bit counterintuitive because it requires you to toggle off the iCloud backup. I'm an experienced user and am still a bit taken aback choosing between the options because, hey, I do still want to back up to iCloud. I just also want a periodic backup on computer.
    GeorgeBMac
  • Reply 4 of 45
    magman1979magman1979 Posts: 1,124member
    "If you're helping new or inexperienced iOS users then you know they never think to backup to iTunes on their Mac." It's a bit counterintuitive because it requires you to toggle off the iCloud backup. I'm an experienced user and am still a bit taken aback choosing between the options because, hey, I do still want to back up to iCloud. I just also want a periodic backup on computer.
    This is not the case with my setup...

    Just did this, and though my iPhone X is defaulted to backing up to iCloud, all I have to do is click the Backup Now option under Manually Backup and Restore and away it goes to the local drive, without changing the iCloud setting.
    randominternetpersonking editor the grate
  • Reply 5 of 45
    entropys said:
    Could this can be done wirelessly on a NAS? Ultimate would be without having to turn on the Mac.  I wonder if there is an app for that?
    It should work fine.  A symbolic link is nothing more than a "pointer" to another location.  If you can "see" the NAS from the command line, then you should be able to point a sym link to it.  Try it and see if it works.  If it doesn't, you'll know immediately and you can delete the link and rename the OLD folder back.
  • Reply 6 of 45
    Mike WuertheleMike Wuerthele Posts: 4,566administrator
    entropys said:
    Could this can be done wirelessly on a NAS? Ultimate would be without having to turn on the Mac.  I wonder if there is an app for that?
    You can do it on a NAS, in theory using mount points -- but you'd still have to use the Mac.
  • Reply 7 of 45
    "If you're going to do this because you're on a MacBook Pro with very limited SSD space then it will still work. However, there will be the onus on you to always make sure you connect that drive before plugging your iPhone in."

    The emphasis on "always" makes me a little nervous.  What happens if you don't have the external drive mounted when you plug in your iPhone?  An error message?  A crash?  Or can you just not backup/restore like that?  I ask because when I go on trips I charge my phone through my MacBook (and I don't bring my external drives with me, not surprisingly).

    Thanks for this tip by the way.  I do hate wasting space on my MacBook for iPhone backups.
    edited August 2018
  • Reply 8 of 45

    Btw.. if I store the back up in the Mac, would time machine have the backup of a backup again? 

    Yes.  In theory, you could trust your Time Machine backup to restore your old version of your local iPhone backup (before you use this trick to do your backups to an external drive).
    bmwintoxicationbaconstang
  • Reply 9 of 45
    Mike WuertheleMike Wuerthele Posts: 4,566administrator
    "If you're going to do this because you're on a MacBook Pro with very limited SSD space then it will still work. However, there will be the onus on you to always make sure you connect that drive before plugging your iPhone in."

    The emphasis on "always" makes me a little nervous.  What happens if you don't have the external drive mounted when you plug in your iPhone?  An error message?  A crash?  Or can you just not backup/restore like that?  I ask because when I go on trips I charge my phone through my MacBook (and I don't bring my external drives with me, not surprisingly).

    Thanks for this tip by the way.  I do hate wasting space on my MacBook for iPhone backups.
    It shouldn't crash. It'll probably give you an error, and break the symlink, forcing a re-do of the terminal entries above.
    randominternetperson
  • Reply 10 of 45
    "If you're helping new or inexperienced iOS users then you know they never think to backup to iTunes on their Mac." It's a bit counterintuitive because it requires you to toggle off the iCloud backup. I'm an experienced user and am still a bit taken aback choosing between the options because, hey, I do still want to back up to iCloud. I just also want a periodic backup on computer.
    This is not the case with my setup...

    Just did this, and though my iPhone X is defaulted to backing up to iCloud, all I have to do is click the Backup Now option under Manually Backup and Restore and away it goes to the local drive, without changing the iCloud setting.
    Hey, sweet! I last tried it a few iTunes and OS versions ago. Things have changed!
  • Reply 11 of 45
    "If you're going to do this because you're on a MacBook Pro with very limited SSD space then it will still work. However, there will be the onus on you to always make sure you connect that drive before plugging your iPhone in."

    The emphasis on "always" makes me a little nervous.  What happens if you don't have the external drive mounted when you plug in your iPhone?  An error message?  A crash?  Or can you just not backup/restore like that?  I ask because when I go on trips I charge my phone through my MacBook (and I don't bring my external drives with me, not surprisingly).

    Thanks for this tip by the way.  I do hate wasting space on my MacBook for iPhone backups.
    I implemented this trick some time ago (did it on Windows in the old times, to a network share, then on my mac, to a micro SD card which is always in the slot but unmounted). The thing I did is disable automatic syncing of the iDevices. When you need to backup, then make sure your volume is mounted (whether it is a local drive or a network share) and then click the "Backup Now" button to trigger the backup. This way your iCoud backup setting is also preserved (it may only be disabled the first time you configure the local backup but not later on when proceeding with the backups) and you can use iTunes as usual, even doing "Syncs" while on the go without your backup volume mounted. You will be able to do syncs as normal while on the go because you'd have restored your "Backup to iCloud" setting, and need to click the "Backup Now" button in iTunes to trigger the local backup. About what happens when the backup is triggered while the drive is away: last time "I tried", iTunes displayed a warning dialog box where it complained it could not perform the action, and that was all.
  • Reply 12 of 45
    Can Time capsule be used as well? Will simlink work for wifi connected HDD? I have it in servis so can not try. Thanks.
  • Reply 13 of 45
    ednlednl Posts: 23member
    It shouldn't crash. It'll probably give you an error, and break the symlink, forcing a re-do of the terminal entries above.
    I (also;)) haven't tested it but what happened to me in a similar situation (a self-made script backing up some directories to an external drive, without checking if the drive was actually mounted) was that the directory tree was created on the main drive itself under /Volumes/diskname. Which I only discovered when next plugging in the drive and backing up again without seeing the free space on that drive go down. In Finder (on the desktop) it was still mounted as "diskname" but on a lower level it was now actually mounted as "diskname 2".
  • Reply 14 of 45
    ednlednl Posts: 23member
    To see how much space you could save, use this in Terminal:
    du -d0 -h ~/Library/Application\ Support/MobileSync/Backup
    (edit) Top Tip I just thought of: I have a Lightning cable hanging off my Mac permanently, I should probably tag it it with a little text label "Plug in MyDrive First!"
    edited August 2018
  • Reply 15 of 45
    The Terminal command shown is backwards! The syntax is: ln -s So what you should be typing is: ln -s ~/Library/Application\ Support/MobileSync /Volumes/Sierra/BackupiPhone/Backup/ By the way, spaces in the link name are perfectly OK - you just have to "hide" them on the command line. There are (at least) three different ways to do this - one of which is actually shown in this line, where the space in "Application Support" is "hidden" by putting a backslash in front of it. This will work just fine on the link's name as well. (You can also put the whole name in single or double quotes). -- Jerry
  • Reply 16 of 45
    Lesson how to use Bash and UNIX symlnks from command line. Anybody who did this knows how to do it. More importantly is why we need this in 21 century with Apple sophistication and we simply cannot point iTunes to different location to keep backups. Is it so tough to swallow for Apple that people do not want their system predefined locations and iCloud for some stuff? For example I am dumping iTunes for my own music and videos because I need to access them where there is no Internet, but reliably while they reside on my own drive. Plex does both ways and I do not mind paying one time for client and run my own Plex server that can be accessed locally or on myCloud over Internet. After all AppleTV now has Plex client app as well. iTunes is about fees and subscriptions these days and Apple ignores people who run their own content. This used to work 5-15 years ago flawlessly. Not now. There you go for all enhancements in subsequent versions of iTunes. Specialized media streaming software is far better than iTunes nowadays. iTunes is still needed to make mobile backups and nothing else.
  • Reply 17 of 45
    ednlednl Posts: 23member
    leichter said:
    The Terminal command shown is backwards! The syntax is: ln -s So what you should be typing is: ln -s ~/Library/Application\ Support/MobileSync /Volumes/Sierra/BackupiPhone/Backup/ By the way, spaces in the link name are perfectly OK - you just have to "hide" them on the command line. There are (at least) three different ways to do this - one of which is actually shown in this line, where the space in "Application Support" is "hidden" by putting a backslash in front of it. This will work just fine on the link's name as well. (You can also put the whole name in single or double quotes). -- Jerry
    No it's not. In the form as it's used in the article: "ln -s [WhatTheLinkPointsTo] [DirectoryName]" a symbolic link will be created in the directory of the second argument, with the (base-) name of the first argument. So that's good.
    Mike Wuerthele
  • Reply 18 of 45
    Strange, I have heard that iTunes backups backup Apps. I have only ever done iTunes backups. Recently, when I've done restores the Apps appear to come from the cloud. The App restores extremely slow, where even a 50 mb apps takes minutes to restore.
  • Reply 19 of 45
    Mike WuertheleMike Wuerthele Posts: 4,566administrator
    imagladry said:
    Strange, I have heard that iTunes backups backup Apps. I have only ever done iTunes backups. Recently, when I've done restores the Apps appear to come from the cloud. The App restores extremely slow, where even a 50 mb apps takes minutes to restore.
    It used to. It doesn't anymore.
  • Reply 20 of 45
    jim01jim01 Posts: 2member
    I desire to back-up my iPhone to a PC running Windows 10 (my Mac is still running OS9, I know...). Can the symbolic link process be specified for this platform?
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