How To Move Your Mac Photos Library To An External Drive

Hi, this is Gary with MacMost.com. Let me show you how to move your Mac Photos Library to an external drive. 

Now if you're running low on internal drive space on your Mac one option you've got is to move your Photos Library to an external drive. Now this is mainly an option for those of us that have desktops. iMacs, MacMinis, MacStudios, and MacPros. It's a little more difficult if you've got a MacBook and you're moving it around because then in order to access your photos you're going to have to have that drive with you too. For Desktop users it's a pretty good option since the drive can sit there behind your Mac and you could just forget it's there. It's just part of your system. 

Now for MacBook users, and for those of us that have Desktops too, there's another option that's pretty easy if you need to clear out space. It requires you to use iCloud Photos, which you probably are already using, but you can use the Optimize Function there. That will save space on your local drive. So, for instance, here in Photos if I go to Photos, Settings, and then to iCloud here you can see I've got iCloud Photos turned ON, and the option that will save you space is Optimize Mac Storage. This means that all of your photos are saved to iCloud but only recently accessed ones and new ones are going to be cached locally. You can still access any of the photos you've got, just that some of them may need to be loaded first. You may not even notice that happening if you've got a fast enough connection. But this could save you a lot of space. You can have, say, a large 10GB photo's library and, with optimize Mac storage, you may only use 2 or 3 GB of space in any given time on your Mac. 

But let's say you'd rather have it Download Originals to this Mac turned ON. So all of your photos are always local in addition to being in iCloud. Or you're really tight on space on your Mac and you really need to get this library onto another drive. So here's what you need to do. 

First you need to get an external drive. Now it has to be a real external hard drive. It can't be like a SD card in a SD card slot or reader. It can't be a flash, USB, thumb drive, a tiny little drive like that. Those just aren't going to fast enough and they are not built to handle the constant read and write. It also can't be a network storage drive. So it can't be a Nas or some other drive on your local network. It can't also, of course, be stored on any other Cloud storage system. You've got iCloud Photos and if you want a Cloud storage system you should just use Optimize Mac Storage. But you shouldn't try to, say, put your Photos Library on Goggle Drive or Microsoft Drive or Dropbox, or anything like that. Also I just want to make it clear you shouldn't be using your Time Machine Drive for anything else except Time Machine. Don't put your Photos Library on your Time Machine Drive or anything else. For one, that means you don't have a backup. The original and the backup would be on the same drive. But also a Time Machine Drive really needs to just be dedicated to Time Machine. So you're going to need a separate drive here. 

Now what you should get is a SSD, a solid state drive. These are the faster drives you can get today and you'll probably need that if you want to continue looking through your photos at the speed that you're used to. If you really need a ton of extra space you can go with a HDD, but those are much slower. 

Now the other things you should know about an external drive is you need to format it correctly. You need to format it at APFS. That's the modern Apple format for drives. It can be formatted MacOS Extended Journaled but there's no reason to format it like that. Use the more modern format. It definitely won't work if you format it for something else, like for Windows. Also, you want to check one more thing. I've got an external drive right here. If I Control Click it, right click, or two-finger click on it and select Get Info you want to look in the Info window. At the very bottom you'll see Ignore Ownership on this volume. It should be checked. If it is not checked, for some reason, you're probably going to have to click this Padlock here, Authenticate with your Password, and change that. 

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Now let's got back into the Photos App here. To begin the process you want to find your Photos Library. In the Photos App go to Photos, Settings, and then look under General. You'll see Library Location. This tells you the location of the library. It's probably in your Pictures Folder, which is indeed where mine is, and it's probably named Photos Library.photos library. But it could be names something else. You can just click Show Me Finder and open up a new Finder window and take you right to it. 

Now there are two distinct situations here. In Photos if you look under iCloud if you've got iCloud Photos turned ON and if you look under General and you see that Use As System Photo Library is dimmed that means that this is your system library. You can only have one iCloud System Library. You can have other libraries but they wouldn't be your one for iCloud Photos. But if this is turned OFF then none of that matters. You're not using iCloud at all. So System Photo Library wouldn't come into play here. Either way it shouldn't change how you actually move your Photos Library to your external drive. But I would recommend that you make sure that the bottom of your library you see syncs with iCloud and that it is complete. There are no pending photos to sync up or down. 

The other thing I would do at this point is consider that this is a very good time to backup the Photos Library. Archive it. Get yet another drive somewhere and actually save this entire Photos Library to it. Even if you're backing up with Time Machine and you're using iCloud Photos it could be useful, for instance, for once a year or after you get back from a big trip with lots of new photos that you store a copy to your Photos Library and put it somewhere off site, away from where your Mac, with your Time Machine backup, are located. If you do that, like I do, then this is a great time to actually update that so you have an extra backup in case something goes wrong. 

Now to move this to an external drive all you need to do is just move it like any other file. So I'm going to create a New Finder Window here. Since I've got those two windows open as the top two windows I'm going to split them so one is to the left and one is to the right, like that. In this window I'm going to go to my external drive. So here it is. I'm going to take the Photos Library, now, and just drag it over there. It is just going to Copy it over. So now I have two copies of it. I have the original still untouched here in my Pictures Folder, in my Home Folder, on my internal drive. And I've got the new version of it here on the external drive. 

Now if I just launch Photos again right now it would just open this one up and ignore the copy I just made. But instead what I'm going to do is I'm going to double click on the one on the external drive. This will open up the Photos App and also tell it to use this library. Not the other one. So now everything looks kind of the same. But, if I go to Photos, Settings here I can see the Library location and it is indeed on the external drive. Also notice if I go to iCloud it says that's only for the system library. That's the one that's still in the Pictures Folder. So back here I see now I've got this button, Use As  System Photo Library Active. So I can tell the app to use this one as my iCloud Library.  

Now if you're not using iCloud Photos, you don't need this step. All you needed to do was to Copy the Library over and double click the new one to Open that. But if you are using iCloud Photos you need to click here. So now it is going to ask you to confirm here and it's warning you that the previous library, the one that we checked to make sure that everything was in sync, that if something wasn't in-sync then it may not get to iCloud Photos. In other words if before we did this it was in the middle if uploading, say, ten new photos and only five got uploaded, then switching to System Photo Library  here means those other five will never get uploaded. But we confirmed that everything was in-sync before so we're not worried about that. I'm going to click Okay here and now we can see it's set as the System Library and iCloud Photos is now enabled. I can check it to complete turning it ON. Now it is going to sync this library with what was in iCloud. Since the contents were identical anyway you can see it is already synced. 

So the final step is to go back to your Pictures Folder and get rid of the original knowing that the copy here is the new System Library. Unless you're really short on space there is no rush to do that. You could do that tomorrow or next week giving you some time to use the Photos App and make sure that everything seems fine. As I mentioned before this would have been a great time to Archive this so you had to get another backup of it. But, if you're sure everything transferred over okay then you can just drag this to the trash.  

Now here's some trouble shooting tips. I showed you how you can double click on a Photos Library to open up the Photos App with that library. Another way to do it is to Quit Photos and then hold the Option Key and then launch Photos. I'll do it here from the Dock. Then you get this little dialogue here that's going to look for all the Photos Library's that it can find on any of your drives and allow you to select one to Open. This is also where you can create a New Photos Library. So you have another way to choose the exact library that you want.  

Another set of modifiers you can use is to use Option and Command. Hold both of those down and then launch Photos. Then you get the Repair Library option. So you can click Repair here and this is if you're having trouble. So if something isn't working quite right or you're getting error messages after switching libraries this is how you can do a repair to see if photos can fix it itself. 

Apple has a support page about this whole process. So if you want to read this over before going through it you can. There's a few more details here as well. I do want to end by talking about my recommendations here. Those are that if you're using a MacBook or any portable Mac that is not going to sit in the same spot all the time, then use iCloud Photos and use the Optimize feature there to save space. 

But if you're using an iMac, a MacMini, a MacStudio, or a MacPro and it is always going to be sitting in the same spot and it's no trouble having external drives attached to it, then you can go ahead and do this if you really feel you're short on internal drive space, although I prioritize my Photos Library so I want it to be an internal drive where it is going to be as fast as possible. But if your collection is just too big then putting it on an external drive for a desktop setup is a decent idea. Just make sure the SSD you get is reliable and fast. 

Also, make sure it is included in your Time Machine or online backup as well because often photos are the most valuable thing that we've got so you want to make sure it is backed up as much as possible. Hope you found this useful. Thanks for watching.