The Ideal Dropbox Setup for External Hard Drives

The problem:

  • You have a MacBook or PC with a hard drive that isn’t big enough for your entire Dropbox account.
  • You have this shiny external hard drive that could hold your entire Dropbox account with space left over.

The solutions that DON’T work, or that I don’t want to use:

  • Symlinks inside your Dropbox. I’m not going to bother providing links to examples. They are everywhere. This. Doesn’t. Work.
  • Some third-party tool that assures you it will be around forever.
  • Moving your Dropbox root folder onto the external hard drive. Because if I left my laptop attached to my external hard drive all the time I wouldn’t have purchased a laptop.

The only solution that actually does work:

  1. Create a new user account on your MacBook or laptop. (you could even give it a username of “Dropbox”.
  2. Setup Dropbox, signing into Dropbox with your account, but change the Dropbox root location to your external hard drive.
  3. Don’t log out. On a mac you can “switch users” so that this account on your MacBook stays logged in and keeps syncing your Dropbox. Switch back to your user account.


  • You still have Dropbox in your home folder, and you still have Selective Sync. The storage on your internal drive is unchanged.
  • With your external drive mounted, you can now see all of your Dropbox.
  • I haven’t confirmed this, but I believe it uses LAN sync.
  • UPDATED on 2/13/2016: One of the commenters, Bob, pointed out in the comments below that you don’t need to worry about changing file permissions on any of the files in your Dropbox folder on the external drive either. OSX will treat any changes to files on an external drive as being changed by the current user. So there is no need to do any kind of massive file ownership change to what is on your external drive. Really great tip that I honestly hadn’t thought about when I started this project!

Un-mounting the external drive:

If you ever unmount your external hard drive, your Dropbox folder is unchanged. When you switch over to the other user account, Dropbox throws a nice warning that simply says “Your Dropbox folder is missing.”

Dropbox doesn’t delete files from your account, and it doesn’t go about creating duplicates. It simply says “I can’t work like this” and waits until you remount the hard drive.

UPDATE Spring 2016:

I wrote this post a year ago, and during that time I found a solution that is much simpler. It may not work for everyone, but if your entire Dropbox account has less than 128GB, this might just work…

I no longer attach an “external” drive, nor do I create a separate Dropbox user account. Instead I use a very tiny form factor USB drive. This USB drive stores 128GB and fits so snuggly into my USB port that I leave it in all the time. It is the SanDisk Ultra Fit 128GB. I got it when it first went on sale for $29.99, and in the past three months it has been holding steady at that price range.

Since my entire Dropbox account is less than 128GB, I just let it all sync to the drive and I never have to worry about it. By the time my drive is larger than 128GB, I’m hoping they’ll have a 256GB model available. 🙂

2016-02-05 18.57.10

UPDATE: April 2016

Dropbox is working on a new prototype that might help, but it is probably a long-way from being available to most of us. The idea is that you can see the files you have on Dropbox without actually downloading them to your device. Imagine “Selective Sync” but still showing the files you chose not to download (very similar to how Dropbox works on an iPhone or an Android device).

Here is the article:


UPDATE: End of May, 2016

I have found that a USB port permanently occupied has been an inconvenience since there are only two USB ports on the MacBook. I’m currently experimenting with using the SD card slot instead (You can see the MacBook’s SD slot in the photo above). I never use the SD card, but I’ve had several occasions where I needed another USB port available.

A normal SD card would stick out of this port, but I have found a couple of interesting SD adapters that are designed specifically for the MacBook and, when inserted, are flush with the edge.

My first attempt didn’t work, because I glossed over the description on this adapter and didn’t realize that a “MacBook Pro 15 inch” wasn’t going to be the same size slot as is on the MacBook Pro 13 inch that I own. So pay close attention when ordering online and make sure that you are getting a Micro SD card to SD card adapter that was made for your specific MacBook.

2016-05-27 21.50.42

That one was about $8, and unfortunately, the cheapest deal I could find for my MacBook was this adapter and it cost around $25. Ultimately though, if it isn’t flush with the edge of the MacBook it will get bumped and knocked out, so it has to be a perfect fit.

I’m waiting for the new adapter to arrive, but I’ve gone ahead with the Dropbox migration. I purchased this 128GB Micro SD card and was using the rsync command to copy files from the USB Dropbox drive to the new Micro SD Dropbox drive.

I ran into some issues where rsync failed and gave some errors, and I think it may have been because the Micro SD card uses the exFAT file system as its default partition type. I started over and formatted the MicroSD card to use OSX Extended (since that is how I had formatted the USB drive) and rsync has been copying without any errors so far. It is still too early to say for sure if this is going to be a working long-term solution, but I’m optimistic.

I love the idea that this will sit flush in the MacBook, so I don’t have to worry about knocking it out. And I’m excited because there is already a 200GB Micro SD card that has great reviews, so I have a little more room to grow if I go the Micro SD route.

UPDATE: Late May, 2016

If you plan to migrate your Dropbox from a USB drive to a Micro SD card, don’t do what I did and try to copy all of the files manually. Because when you go into Dropbox and tell it to change the location of Dropbox to the new Micro SD card, it will say “There is already a Dropbox folder there” and you’ll have to delete the folder. Dropbox insists on moving the files for you, which honestly I prefer.

Also, the right SD card adapter is worth the money. This was clearly made for my MacBook! I’m going to be keeping notes as I continue to use this device.

2016-05-28 10.09.37

One thing I’m noticing right away is the speed difference. The SD Card slot on the MacBook is much slower than the USB 3 slot. I ran a speed test for each of the two drives, the the SD card was considerably slower. I’ll consider uploading the comparison. When I saw this Micro SD card adapter, I thought this would be a cut and dry solution, but the speed is definitely a factor. At times my MacBook was crawling. Some things I’ve learned:

Make sure that you format the Micro SD card using one of Mac’s partition types. OSX Extended or OSX Extended Journaled. I was using exFAT originally and it was impossibly slow. After I switched to OSX Extended, it sped up quite a bit.

The slowness affects how fast Dropbox can actually download and sync your folder. Since the IO write times are slower, Dropbox moves slower too. For example, when I open Finder, there is a bit of a lag as folders populate.

I feel like the OS is slower overall, but I haven’t quantified this yet. When I take the card out, it seems like the OS speeds up considerably.

With the USB 3 drive, I created another folder called Applications and moved some of my larger Mac Apps over to the USB. There wasn’t any noticeable change in the performance of most apps. I haven’t attempted to do this with the SD card, because I don’t think it will be able to keep up, but I’m planning to try it. If I could move larger applications over to the SD card, that would be ideal since the form factor can’t accidentally be bumped out.

Once Dropbox gets fully synced, the SD card might be a good solution for Dropbox, but my gut here is that it won’t work well if you have a lot of things that write directly to Dropbox (like 1Password, or using Photoshop with files in your Dropbox).

UPDATE: June 2016

I’m going to start logging all of my notes for the Micro SD card on a new post.


116 thoughts on “The Ideal Dropbox Setup for External Hard Drives

  1. I would love to do this, but I’m a little confused. Do you need to create a new Dropbox account or just use the one you already have? I’m a little nervous to use the one I already have — won’t it delete everything and sync to the new user account?

    • Rob, yes, you’ll have Dropbox running inside both Mac user accounts. Let me clarify:

      Mac User A – think of this as your personal login on your Mac. You probably have Dropbox installed in your Home/Dropbox folder. You have Dropbox installed and are logged into the only Dropbox account that you have. You have also gone into the settings and used “Selective Sync” so that your large folders (like Photos and Videos) don’t sync, so when you look in your Home/Dropbox folder, you don’t have folders for Photos or Videos.

      Mac User B – I’d recommend creating a user account on your Mac with the username of just “Dropbox” so it is obvious. Log into that account on your Mac. Dropbox is probably already installed, but you’ll need to log into Dropbox (again, using your Dropbox account, you only need one for this method). But when you are setting up Dropbox for this Mac user, you’ll change the Dropbox folder location. Instead of Home/Dropbox, you’ll tell it to set up at /Volumes/MyHugeExternalHardDrive or possibly /Volumes/MyHugeExternalHardDrive/Dropbox. You shouldn’t need to do anything else, because “Selective Sync” is off by default, but you might want to just go in there and make sure you AREN’T using Selective Sync here, since you want everything to sync to your hard drive.

      I hope that makes sense.

    • Rob,

      I’m not sure I follow, but I’m going to guess… After a reboot, maybe the Dropbox user isn’t logged in yet, so Dropbox isn’t working in the other account. Does that sound right? If so, log in as the Dropbox user and see if it works again. I might need to find a way to log in this user automatically in the background after a reboot if that is the issue.

  2. That sounds great! Can I still do this somehow if my external disk is now linked to Dropbox with my main user account on a Mac? Thanks!!!

    • I’m not sure if I completely understand your question, but for the most part, yes. 🙂 Think of the Dropbox folder on your external drive as an isolated instance of your Dropbox account. So if you login as one user and setup Dropbox to sync to the external drive, you could theoretically log into the Mac as another user and tell Dropbox to sync to the local drive. You would probably want to use Selective Sync, and keep in mind that you’d have Dropbox storage in two places, but it works.

  3. Thank you for this idea. Please clarify one thing. Once I switch back from my Mac Dropbox user account to my Personal user account, what would happen if I change the Dropbox folder to the new one on the externall drive? Would that now let me access a full instance of my files without using Selective Sync and the smaller internal drive?

  4. what am i doing wrong.
    1. new user account – check
    2. external hard drive – check
    3. getting dropbox root folder on external hard drive – 😦

    i am apparently doing something wrong – i have installed dropbox onto this new DB user account. when i go to add my dropbox folder – i go to advanced settings and am trying to get it to place the folder onto the external hard drive – i get an error message that states: ERROR WITH SELECTED FOLDER – CAN’T CREATE A DROPBOX FOLDER IN THE REQUESTED LOCATION.
    can someone please help….. pretty please – i am sure i am missing the obvious, but would greatly appreciate someone pointing it out to me.

    • It is hard to say for sure, but here are my thoughts:

      I recently tried to install Dropbox on a new USB drive, and one thing that I noticed is that you can’t store THE CONTENTS of your Dropbox at the top level of your drive. Meaning that Dropbox must always be in a folder called “Dropbox”. I haven’t tried naming my USB drive “Dropbox” to see if I can get around this, but I have a new USB drive arriving this week and I’m planning to try it on that one.


      The other thing that I think I’m hearing from your comment is that you created a DIFFERENT account on Dropbox. You don’t need to do that. You should only have one registered account on

      When I talked about creating a “second login” in the article, what I meant was that you create a new MacBook User. So when you turn on your Mac, you can log in as you, or you can log in as a user called “Dropbox”. Now, back to your issue:


      The error you mentioned: “CAN’T CREATE A DROPBOX FOLDER IN THE REQUESTED LOCATION” happens when you don’t have permission to make changes in that folder. For example, you can’t install Dropbox to “/root” because that directory is owned by the “root” user, and Dropbox run with your user permissions.

      Check to see if the directory where you are trying to install Dropbox is owned by your user. If it is not, you’ll need to use “sudo” privileges and change this on the command line (open the “Terminal” app). If the directory is “/Volumes/External” you could try:

      “sudo chown -R $USER: /Volumes/External”

    • The same happened to me. I had to use Disk Utility on my Macbook Pro to format it for OS X Extended (Journaled). Now it works.
      And I didn’t have to create a new user account because I’m using an SD card.

      • I’ll have to look and see what format I’m using on the card. With OSX Extended (Journaled), when you log onto, does it show all the hidden files?

  5. thank you! i miswrote my previous post – i had added a new account to my macbook – not DB. the error i was making was a complete oversight on my part. a quick reformat of the new hard drive solved my issue. i do have a few more questions. i apologize if these seems obvious, but i would rather ask than make a mistake that will wipe out all of my files.

    now that i have all my files on my external hard drive – my goal it to jump back and forth between my laptop and home computer. i have added an extra account on both machines.

    1. when i start up and shut down & when i plug in and remove my hard drive – do i need to do this while signed into the new accounts and then switch users once i am synced?

    the fear of having drop box erase all my files because i carelessly miss a step is a bit overwhelming.

    • I’ve found that if I simply pull out the hard drive, without unmounting it, two things happen: OSX warns me that I didn’t safely unmount the drive, and Dropbox throws a warning that says “The Dropbox folder is missing” and puts everything on hold until I put it back. You’d want to experiment with this carefully until you are comfortable with it, of course. If I’m going to remove a drive, I usually quit the Dropbox application, then unmount the disk, then physically disconnect it. After you’ve done those steps, if you try to start the Dropbox application, it throws the same warning and says, basically, “I give up, because I can’t find the Dropbox folder.” But to answer your question, I don’t do anything when shutting down the computer or logging in as another user etc. For the most part, with this setup, I can set it and forget it.

  6. Sometimes the best solutions are both simple and obvious in hindsight. I can’t believe I hadn’t thought of this! You’ve saved me from going down an over-engineered and flawed solution which would at best work imperfectly.

  7. What if you simply shutoff dropbox from autostart and only run when you need it and make sure the MyHugeExternalDrive is already mounted before running dropbox. That way you do not need another ‘dropbox’ user account on your mac. Will that work or does it have problems?

  8. I absolutely love this idea and it has been working great for me. I have been logging in and out of the dropbox account just to make sure nothing gets corrupted by just pulling the drive … and then a bit of inspiration struck. Command line! This on OS X.

    1. Login to the Dropbox user on OS X (we’ll call this user DPX to avoid any confusion)
    2. Open System Preferences
    3. Enable “Remote Login”
    4. Allow access for “Only these users”
    5. Remove “Administrators”
    6. Add your dropbox user “DPX”

    Now go back your normal user.


    1. Open terminal
    2. ‘ssh dpx@localhost’
    3. Enter your dpx user password
    4. ‘open /Applications/’


    1. Open terminal
    2. ‘ssh dpx@localhost’
    3. Enter your dpx user password
    4. ‘killall -1 Dropbox’

    I tried using osascript but OS X didn’t seem to recognize it over a session but a kill -1 seems to be as safe as you can get otherwise.

    I’m sure these can be packaged up nicer but recommend against hardcoding your passwords if you go that route.


    • Hey Robert,
      The command line approach sounds like a great idea but I’m wondering if I understanding it correctly. Is this is just an attempt to open/close the dropbox app from the main account “while still having to run the DPX user” or “without having to logging in DPX user at all”?

      When I first read it I thought it was meant for the latter but I can’t seem to be able to do it properly. ( I think ‘open /Applications/’ is only open the .app folder, not running the executable.) But if you meant to just have control while having to login both account anyway then I think I rather just manually switch user.


    • I’m curious, Robert, did it work for you to login as DPX and enable Dropbox to start as a login item? If not, this certainly works, I just haven’t tested it myself.

      Thanks for the comment!

    • You always have to login to the DPX user (I’m not advocating any autologins – so don’t do them). For start login item, one must still unfortunately login.

      My use case has me connecting and disconnecting fairly often. I do have to login in once to the DPX account and then user switch to prime account. I almost never completely shutdown the laptop so that works out fine. I’ve also made the process MUCH easier.

      1. SSH Public key exchange so I don’t need to enter passwords
      2. Created two automator workflow applications for the startup and shutdown scripts

      Create Start Automator App
      – Run Shell Script action
      – Shell (/bin/bash)
      – Pass input to stdin

      #comment – start dpx dropbox
      ssh dpx@localhost ‘open /Applications/’
      echo “DPX Dropbox Started”

      Create Stop Automator App
      – Run Shell Script action
      – Shell (/bin/bash)
      – Pass input to stdin

      #comment – stop dpx dropbox
      ssh dropbox@localhost ‘killall -1 Dropbox’
      echo “DPX Dropbox Stopped”

      3. Dragged apps to dock

      Next step is maybe a menulet that manages and shows activity.

  9. Thanks for the tip! Trying it out, fingers crossed! Before discovering this I simply changed the Dropbox folder location to my external drive on my main user account. This resulted in files being deleted off my Dropbox when I unmounted the drive which sent me on a search for other methods. My only question is, how is creating a new user account with the Dropbox app syncing to an external drive going to prevent files from being deleted once I unmount the drive? Seems like the reason Dropbox begins to delete files is because it notices that all the files are gone once the drive is unmounted. How and why does this behave differently when on a separate user account? I want to be sure that I don’t run into this issue in the future. Thank you!

    • Thanks for replying igorcheb. I’ve honestly never had this happen to me, so I can’t say for sure. Did you unmount the drive before unplugging it? That is the only way I’ve ever tested it, and as soon as I unmount the drive, Dropbox throws an error and says essentially “I can’t do anything if the folder where Dropbox is supposed to be isn’t there anymore!”.

      A couple thoughts that might help you test it:
      * Maybe create a throwaway Dropbox account you can test on without risking the loss of your real Dropbox account.
      * Maybe check to see if you are using a symlink. A symlink would stay there even when the drive got unmounted, so Dropbox WOULD think you deleted all the files all of a sudden.
      * ON THE THROWAWAY ACCOUNT, maybe try running Dropbox, then un-mounting the external drive before you unplug it and see if Dropbox throws the error that it should.
      * After that, ON THE THROWAWAY ACCOUNT, try running Dropbox with the drive mounted again, and just rip the USB out and see what happens. OSX should show an error saying “Please unmount before you do that” and Dropbox should say “I can’t work like this”.
      * If all else fails, a less-convenient way, but one that I know works for sure, is to ALWAYS close the Dropbox application before un-mounting the drive. In this case, you wouldn’t want the other OSX user, because you’d also need to unmount it there, which is messy, but you gotta do what works for you.

      I actually picked up a SanDisk UltraFit USB drive with 128GB on it off of Amazon when it was on sale for $29 and I’ve been using that for now. With that setup, I don’t use the bigger 2TB external because my whole account is under 128GB, and so I don’t have the extra OSX user called “Dropbox”, I just link Dropbox in my OSX user account to the thumb drive. Now I can carry the laptop around without thinking about detaching the cable, and the external drive is used for larger things I don’t keep on Dropbox anyway. Obviously this doesn’t work for folks with more storage in use, but for me it has worked really well.

      • Hi there, I want to try doing this, I read your instructions and I think I understand – but I haven’t read ALL the way thru subsequent threads so if this question is answered elsewhere apologies. My Dropbox folder is on my Mac desktop, can I just drag that onto my EHD and then set up as you advise ? Otherwise I think it sounds like I am setting up a new folder (on the external), in which case, do I then move all the desktop across ? I’m just worried that if I log out to create new location all the stuff in the original desktop folder is going to get deleted.

      • Keith,

        I honestly haven’t tried dragging and dropping a folder onto the external drive. Here’s what I do know:

        • When you drag your Dropbox folder from the Desktop to your external drive, a Mac is going to copy the contents of the Dropbox folder by default. It won’t move the folder, it will make a copy.

        What I don’t know is how Dropbox will react. It might look at those files and simply say one of the following:

        • “Yep, those are the same files that we already knew about, so your Dropbox folder is all set!”
        • “Nope nope nope. Those are all conflicts. Now we are going to create duplicates of ALL THE FILES YOU JUST ADDED TO DROPBOX.”

        I ran a quick test on El Capitan, and the modified date of the file I was testing on my Desktop was from July. When I dragged and dropped it into my Dropbox, the modified date stayed the same: July. So you have a good chance that Dropbox would not freak out on you, but if you have more than a few hundred megabytes in your Dropbox folder, you should probably test this in phases so it doesn’t completely wreck your Dropbox account.

        I’d love it if Dropbox had a way to test these things, but I don’t know of a way aside from just creating a throwaway account and testing it. If you wanted to go this route, you could even create a new user on your Mac and setup Dropbox right from there. To do that, you’d want to have a folder that you upload first, then try moving the Dropbox location and testing with a smaller set of files.

        I hope this helps. If you end up giving it a shot, please report back and I’ll try to update the post with more advice.


      • Hey, thanks for this, yes of course if I drag folder to EHD it’ll copy, so maybe the way forward is to do that, then set up the new user account, then link that account to the newly located dropbox folder (on EHD), and delete the desktop original (once I’ve checked everything). My primary purpose for wanting to try this is to free up space on my macbook HD, will I achieve that doing this ? Thanks for your input, Keith

      • Hi again, So, I tried this. In Dropbox preferences I changed the location of my Dropbox, to do this I had to create a folder in the EHD which I just called Dropbox Home. Once I’d done that all I had to do was carry on – in other words, Dropbox/Preferences/Account/Dropbox location…and then the new folder in my case Dropbox Home. As soon as I did that the Dropbox re-located, I didn’t drag and drop anything, the folders all populated the new location and when finished the Dropbox folder off my Desktop disappeared. I checked, and all my files are safe, I created a ‘dummy’ folder (on desktop) and dropped it into Dropbox and it synced with ipad and iphone as normal. Freed up 8gigs which is handy. I think Dropbox have made this easier because I tried to do the same 3 years ago and I couldn’t make it work.

  10. I liked your solution first, but then with few hours of trial and error, found following setup is more suitable for my use cases:

    So I have SD card (128gigs) constantly mounted in my mbp13 and 1TB external hdd that used to store photos that are uploaded to Dropbox and stored there (200+ gigs and growing).

    I’ve tried tricks with tar archive utility and rsync – nothing helped, Dropbox client was starting as unlinked if I did something with it’s ~/.dropbox.

    So my solution was (works on OS X and Linux):
    1. Unlink Dropbox account and re-link it with Selective Sync enabled (without photos) to store Dropbox folder on SD card.
    2. Wait till it finish all it’s sync and quit from Dropbox app
    3. MOVE (not copy, mv command from command line): mv ~/.dropbox ~/.dropbox-sd
    4. Start Dropbox (it will start as not linked, cause it can’t find ~/.dropbox that we recently moved/renamed) and link it to the same account, but without Selective Sync (all files synced), to external drive.
    5. Wait till it will finish synchronize all the stuff and quit from Dropbox app
    6. Move/rename (same as in 3) ~/.dropbox to ~/.dropbox-external AND ~/.dropbox-sd to ~/.dropbox
    7. Start Dropbox app, it will update file list from the server and in a few seconds (minute maximum) it will be the same as before we started all this deal.

    Now, when you need to work with external drive or internal storage – all you need is just to play with renaming these two folders, depending on what version you need.
    WARNING: Just be sure you’re closed Dropbox app before any manipulations with it’s folders. Personally I use “Activity Monitor” to ensure or “ps aux | grep Dropbox” console command.

    I use such setup one day for now, and haven’t noticed any conflicts or something bad.

  11. You are the dogs bollocks, the cats meeow, a genius, deserving a Nobel prize for something!! Bloody brilliant! Works like a charm. James

  12. Having sung your praises above……I have one anomaly. I am using Picasa on my MacBook, and it shows two copies of every image folder and corresponding images. I checked storage usage as well as DropBox online and there does not seem to be any duplication or doubling of memory used. Any idea why this is happening?

  13. I did this last November and my Dropbox is still working absolutely perfectly in new location on external HD. It was really simple : In Dropbox preferences I changed the location of my Dropbox, to do this I had to create a folder in the EHD which I just called Dropbox Home. Once I’d done that all I had to do was carry on – in other words, Dropbox/Preferences/Account/Dropbox location…and then the new folder in my case Dropbox Home. As soon as I did that the Dropbox re-located, I didn’t drag and drop anything, the folders all populated the new location and when finished the Dropbox folder off my Desktop disappeared. I checked, and all my files are safe, I created a ‘dummy’ folder (on desktop) and dropped it into Dropbox and it synced with ipad and iphone as normal. Freed up 8gigs which is handy. I think Dropbox have made this easier because I tried to do the same 3 years ago and I couldn’t make it work.

  14. Ok, maybe I’m missing the obvious here, but how do you get the file to your main account? I have this all set up. I can access all files on my secondary account (called Dropbox). I have Dropbox installed on my main account with selective sync. Should it automatically find the dropbox folder? Should I tell Dropbox on my main account to look on the external hard drive?

    • Tim,

      No worries, this can be kind of confusing when you are getting it setup. Let me make sure I understand your setup so far:

      1. You are on a Mac, and your Mac login for user “Tim” has Dropbox installed.
      2. You created another Mac user account, logged out of the “Tim” account, and logged into the Mac as “Dropbox”.
      3. You connected the external drive to your Mac.
      4. As the Mac user “Dropbox”, you setup the Dropbox application and told Dropbox to set the “Dropbox location” to this external drive. (side note, Dropbox won’t let you set it to the root of your external drive, so you probably have something like this: /Volumes/ExternalDrive/Dropbox).
      5. While logged into your Mac as “Dropbox”, you don’t have Selective Sync enabled, so your entire Dropbox account syncs to the external drive.
      6. You logged out of your Mac “Dropbox” user account, and logged back into your Mac as “Tim”.
      7. You open the Dropbox application for the first time (or maybe you already had it installed, either is fine).
      8. You go into the Dropbox app preferences and set the “Dropbox location” under the Account tab.

      If all of that is correct so far, you are on the right track. From here, you have a few options:

      1. Technically, you can set the “Dropbox location” for the “Tim” Mac user to the external drive, but this isn’t ideal, since it is basically the same as what we did for the other Mac user called “Dropbox”.
      2. Instead, and what I’d recommend, is you keep the “Dropbox location” for the “Tim” Mac user on your local hard drive.
      3. After that, you immediately go into Selective Sync and turn off all the large folders that won’t fit on your internal hard drive.

      “how do you get the file to your main account?”

      I think what you’re asking here (please send me an update if I’m misunderstanding) is “how do I see all those other files on my external drive?”

      For that, you simply use Finder. You browse to the external drive and view them in /Volumes/ExternalDrive/Dropbox.

      As long as you are connected to the external drive, this is all good. And as soon as you disconnect from the external drive, you won’t be able to browse that drive obviously, but the idea is that you have a smaller copy of your essential Dropbox items on your local drive in the “Tim” Mac user account.

  15. Just one question… I am doing this, so that I can sync between two hard drives on two computers, as well as having the extra back up on the cloud. In the unlikely event that one of the hard drives every fail, moving my drop box root system on a replacement hard drive, may, in my thinking, tell dropbox that I deleted everything. Would that be correct? If that is the case, would the safe route be simply to reinstall drop box on that user account to get around that?

    • Jerry,

      That’s a good question, but I honestly don’t know what would happen. I’ll take a couple of guesses, but I think it would depend on how the drive actually failed.

      1. Assuming the drive crashes and is immediately unmounted, I’d predict that this would have no effect. I would think that Dropbox would just say, “Nope, the drive is gone, I’m quitting.” (again, I can’t guarantee that, but when I yank out the USB cable on an external drive with Dropbox on it, that is what happens on my machine).
      2. Assuming the drive crashed or got corrupted somehow but stayed mounted: this is probably less likely to happen, but I suppose it is in the realm of possibilities. Let’s say the drive got corrupted and could no longer read the files. Dropbox might still detect that the drive is mounted, but then might think it was immediately empty. What would happen here? I’m not sure.

      One new feature that might protect you is Dropbox’s bulk-delete warning. A while back I was cleaning up my photo collection and bulk-renamed a bunch of files and then bulk-deleted a bunch of duplicates. Dropbox sent me an email saying, “We noticed that you recently removed a large number of files. If you’d like to review this change, click here.” I think I was even given an option to revert the changes, but I’m not certain.

      That is a big piece of mind for me though in even testing these things.

      Hope that helps.

      • Ok so I don’t this works with windows 10. When I switched back to my default user account, my dropbox was moved from my C drive onto my external hard drive as well, and I could not access it in its usual place.

      • Nevermind. It did work, I’m just a dummy. The icon for dropbox that was pinned to my taskbar no longer worked, and I assumed that it was because Dropbox was no longer in my C drive as well. But when I opened my file explorer, lo, and behold, it was right there staring me in the face…

  16. I just implemented your original idea on a MacBook Pro (my Dropbox is 500 GB so the tiny USB isn’t an option), and it works beautifully. When I first set it up I jumped through some hoops to change default file permissions on the assumption that would be necessary for both users to be able to work with the files transparently. I then discovered this wasn’t necessary–it turns out that by default OS X treats a file’s owner as being the user currently working on the file–as long as the file isn’t within the /Users/… hierarchy.

    So now my most actively used files are on my internal hard drive, and less actively used ones are on the external drive, and they’re all in the same Dropbox!

    Thanks again for this absolutely brilliant solution.


    • Great Bob! It honestly never even occurred to me that you’d have to think about file permissions, but this is a really important point. In fact, I think I’ll update the main article with a note about this, because I could see someone with an IT or Systems background really sweating this.

      Thanks for sharing!

      • A little over a month later: This continues to work perfectly. And its elegance becomes more apparent the longer I use it. For example, having a separate user login for Dropbox access to the external drive helps keep me from accidentally having Dropbox attempt to access it when it’s not there.

        Thanks again for something that has been hugely useful.

  17. After reading your solution and all the comments, I’m still confused.
    I am on a Surface Pro 3 running Windows 10 and want to use both the internal SDD and a 200 GB micro SD card.
    Ok, I create a new Windows and set up a new DropBox location.
    But then? Does this user have to stay logged in?
    And when I reboot, do I have to login this user as well? If so, can that be automated?

  18. To avoid ._* files on external drive, may need to use Disk Utility to format as HFS+ (MacOSX-extended). On non-hfs system, in most cases for every file you copy to it, two files are created by os-x, and dropbox syncs both of them.

    So far there are cleaners for the ._* files, but no easy way to prevent them. So, if you want to use that drive on non-mac system, setup two volumes: one hfs+ for dropbox, and the other formatted to some non-hfs+ filesystem, like FAT32 or exFAT. So far there is no easy/robust way on mac-sox to keep your Dropbox folder on a non-hfs+ filesystem, for reasons described in links in at (a free alternative to commercial mac-cruft cleaners like BlueHarvest.) At least one link mentions requests to dropbox folks to add ability to ignore ._* files, but that may not happen in near future.

    But also note that reformatting sandisk may make it slow: I have two of those 128gb sanddisk flash-drives used only on windows, which run quite hot btw. Stick A was set-aside and never used so far. But I let windows reformat stick B so it would boot as a recovery usb, but read/write performance became very slow, even tho filesystem was same as OEM, namely fat32. I returned stick-B to same partitioning and format as the untouched OEM stick-A (using dd command in linux), and luckily stick-B read/write performance was no longer so slow. In a follow-up, I’ll post the OEM partition table info here is others need it. I’ll be trying the samsung tiny usb3 sticks as well, and see if they have any huge speed issues if reformatted (such as to HFS+ for use as Dropbox location.)

    Earlier attempts using folder-actions ran into race conditions: if you removed the ._* file the Finder may corrupt or not copy correctly the rest of the file. One way to prevent creation of ._* files is to avoid use of the Finder, and instead copy from a Terminal shell with with “cp -X”, hardly ideal but good to know about. I need to test if -X still works if you do a “cp -p -X”. Apple has hacked many utils such as tar and others to include those damn ._* cruft, so I’ve taken to using gtar gcp by:

    brew install coreutils

  19. I followed this advice. Seems to work, but the ex HD was disconnected and now it is suggesting I move the dropbox folder back to the original location, but I can see it is still there, and to launch dropbox again. Do I just ignore this message?

  20. I have a small business I’m trying to assist with this set up. Trying to consolidate dropbox to fewer computers because of hard drive wear. So the question is if the main computer has a mounted 4tb Ext HDD as it’s dropbox folder and that HDD is shared there shouldn’t be an issue with dropbox sync/update if non-dropbox PCs open/save from the shared folder.

    • Chris,

      I don’t foresee a problem with that, but I’ve never done it. You are basically saying that you’d open a Shared Folder (Like a Windows Share or a Samba Share) with Dropbox in that folder. In that case, as long as the users on the network have read/write access to the Windows Share, then it should work just fine.

      If you do get that setup, would you mind to reply back here and let us know if you run into any issues or if this works out for you?


      • Actually, I was planning to assign it a letter then just share the whole drive since it would only be for dropbox. But I will definitely report back.

  21. Thank you, Thank you, Thank you! I was about to spend quite a bit of $$$ on a new MacPro in hopes it would solve my dropbox issues. That’s when I stumbled upon your posting. Created the new user, named it dropbox and wouldn’t you know ALL 1TB links downloaded and I now have plenty of space on my macbook pro. God Bless! Thanks for sharing. You ROCK!

  22. Hi there, Much like everyone else I was searching for a way to keep my dropbox data on a secondary drive away from my main computers hard drive which is full to capacity with software. I stumbled across your blog and I wonder if you can confirm that this is an entirely safe option.
    It seems that dropbox strongly advise against this method: (Scroll down to Advanced users)

    I normally work directly in dropbox on my desktop so that it is constantly backed up. I usually work on photoshop and other such heavy files. Is it safe to do this directly from the Flash drive similar in the way you have done? I heard that flash drives have some kind of expiry date since there is a limit to how many times you can transfer data?

    Just some thoughts I’d throw out there before I test this out.

    • Bill,

      Thanks for your comment. I will certainly not go on the record as defying the written instructions posted on the Dropbox Help. 🙂 Having said that, a lot of folks here have been able to do this and I’ve not had anyone come back and report those types of errors. But I absolutely agree with Dropbox in saying, “tread carefully”. Your case is a little different, however, so it is probably worth commenting on it.

      Working directly on a Photoshop file that lives in your Dropbox folder could be tricky. I don’t believe they are a “binary file”, but they are large and I’m assuming there can be significant amounts of writing going on with each save. I’d be more cautious in your case than I would in most of the other cases for that reason. A lot of folks who are using this method have things like MP3s, Images, and other items that don’t get altered too much; or they get altered and then copied into Dropbox and are done. In your case, I think you could see the flash drive or external drive wearing out faster, but I don’t know that for sure – I’d just assume that you’d be doing far more writes than the average user. On top of that, I’d guess that your Photoshop work is either Client Work, or part of a Portfolio, so is more mission-critical than things like MP3s.

      I won’t ramble on much more about it because I’m mainly speculating, but if you aren’t comfortable with the solution, I’d say trust your gut. 🙂

      One option might be to setup Dropbox on your hard drive, but use Selective Sync and ONLY store the directory where you do your Photoshop work. Then, on the external drive, setup Dropbox without Selective Sync. In that case, you’d still be saving your Photoshop work to your local drive, Dropbox could sync it, and it would get synced to the full Dropbox on your external drive.

      Ultimately, I would urge you to experiment with it using files that are disposable and see what you find. In all of my tests, when the External Drive got unmounted, Dropbox caught the error and stopped – waiting until I fixed the issue before it tried to delete files. But if you were in the middle of a file transfer (or a Photoshop file save) and this happened, it is possible that work could get lost.

      Best answer: test it out with disposable files and see if you are comfortable with the results.

      • Thank you for your detailed reply. You assume correctly however I just want to follow up your idea of using selective sync on my desktop and then the external drive for my main dropbox files, because I do not think I am understanding correctly.
        I have changed the Dropbox location to sit on my external drive instead of my computers hardrive… so then how would I set it up also to have selective sync on my main computer?

      • Bill,

        Sorry for the confusion. The method I was referring to was the original method where you create a separate user account on your Macbook. Not a separate Dropbox account, a separate way to log into your Mac. Many people just auto-login and don’t even know that you can create another user account. Here was the original way I was using Dropbox with a big fat Western Digital external drive. Don’t do these steps just yet, just read through them first so you get the idea. I’ll explain as I go:

        0. You have a Mac login (you may not even be aware of this), but if you have to enter a password when you turn on your Mac, this is the type of user account I’m talking about.
        1. Create another Mac account. When you are logged in, go to Preferences –> Users & Groups. Click the padlock in the lower left and sign in and then you should be able to click the Plus icon in the bottom left corner of the Users list.
        2. What we would do here is create a new account on your Mac that is ONLY going to be used by your Dropbox account. I called the user “Dropbox” and I even dragged a Dropbox Icon as the Profile picture so it was clear. This doesn’t have to be an administrator account, it can be a standard user. Set a password, then log into the Dropbox user account.
        3. Now, once you have logged in as “Dropbox” on your Mac, you set up the Dropbox app as normal. Except when it comes time to picking a location for your Dropbox, instead of “HOME/Dropbox”, you pick “/Volumes/MY_HUGE_EXTERNAL_DRIVE/Dropbox”. Let me break out of the bullet points to clarify here…

        You will still log into your Mac as “Bill”, and another user “Dropbox” will stay logged in all the time. Inside your “Bill” Mac login, you’ll use selective sync and ONLY sync your work folder that you use in Dropbox. The Dropbox user, on the other hand, stays logged in all the time and syncs everything to that big external drive (though one user pointed out that after a reboot you have to log in as Dropbox again to kick it all off). At the end of the day, you have your files that you work on locally in your HOME/Dropbox folder, and the Dropbox Mac account syncs everything that is in your Dropbox to your external drive.

        Again, I’d reiterate that I’d feel a heck of a lot more comfortable if you tested this out HEAVILY before you go all in with it, but that is the gist of what I was doing. It worked for me for as long as I needed it. Keep me posted.

      • That’s perfect. Thankyou for your reply I really appreciate it. I think this is a great idea for someone who has a workflow such as myself. I guess the only thing to remember is to log into the ‘Dropbox’ user when I attach my iPhone so that all the photos are synced. Half the problem is that camera uploads consume so much space but at the same time I need a local version in order to back them up.
        Thanks again.

  23. Pingback: Using a Micro SD Card on a MacBook for Dropbox | approductive

  24. Hey,

    I just crossed the same issue and resolved this issue using the ControlPlane: I created to contexts based on the HD mount rule: if my dropbox hd is mounted then run dropbox; if my dropbox hd is dismounted kill
    It seems to be working.


    • Hey Daniel, have you got this working if there’s an unexpected removal of the HD? Works great for me if I eject if properly by unmounting it, but if someone yanks out the cable, ControlPlane doesn’t always register that it’s been dismounted… Any ideas?

  25. Reading all the success stories here I’m about ready to pull the trigger. However, the varied success stories above apparently all come from Macs and I am running Windows 10 on a new Dell PC. I understand the two usernames on the same computer and use Selective Sync to keep those essential files to my username/internal hard drive, and memory hog files (photos, video, audio) to the external drive with my a ‘dropbox’ username. Where I’m a bit unclear is whether or not I need to download and install dropbox twice? Or do I download to hard drive just once? How do I then move a copy of dropbox to the external drive? My understanding is that once dropbox is found in both respective places then I can selectively sync the appropriate files to their respective places. With this said…I still feel like I’m missing a key step or two.

    • JL,

      Once you have installed Dropbox on your Windows machine, it should be installed for all users (not certain of that, but it is typically the case).

      If so, you could just create the Dropbox user account (a Windows login). After you login as the “Dropbox” user, open the Dropbox app and go to preferences and tell it, “I don’t want to install this to C:\Users\Dropbox\Dropbox, I want to install it to G:\” or whatever the external hard drive letter is.

      Once you have set that up, you would simply do a default install, which would pull down your entire Dropbox contents and put them on the external drive at G:\ (or whatever letter it is).

      Back in YOUR Windows login, you would just set up Selective Sync and only keep synchronized the folders that you will need to have available when your laptop is unplugged from your external drive.

      Let me know if that makes sense.

  26. I want to have a backup of my Dropbox in case Dropbox gets corrupt and my files get jacked on their server. So I have read almost all of the comments and what I am understanding is that the “Dropbox” user will just be another green checked sync folder? But if something happens to the actual Dropbox online then that would mess up my external hard drive docs, correct? So how do I have a “backup” in case the world crashes?

    • KRob,

      That doesn’t sound correct to me. The Dropbox user is not another folder that gets synced inside your Dropbox, it is another account on your MacBook. Instead of one folder inside your Dropbox folder, I’m proposing another User account on your MacBook. The new user account on your MacBook would sync all files to an external hard drive, and your MacBook login can use selective sync.

  27. I have done a similar thing with Google Drive where I have both a personal and work account that I would like to have synced onto my machine so I run each as separate accounts. I honestly find the solution clunky and I when I reboot 9/10 I forget to log into the secondary account which just handles the syncing of the other account. Yes, this will do the job, but it’s clunky. DropBox needs to do two things:
    1) Allow you to split your DropBox syncing into multiple locations on your file system, including different storage media
    2) Allow you to run more than one DropBox account in a single user account.

    Considering the clamoring for at least #1, I am disappointed Dropbox has not followed through.

  28. Hi, glad to have found this blog. I am getting about 80GB of files (photos I have to sort through and import selects into Lightroom to do light editing) synched into my Dropbox on my iMac Desktop and running low on space on my hard drive. I have two mac accounts on my mac already, (from previously migrating my old mac book onto my new iMac desktop) and on both accounts I have Dropbox installed. In order to save my hard disk space, can I mount an external HD and move my Dropbox folder over to the external HD in one of my mac accounts and do select sync in the other account for the files I would like to work on? Thank you, I appreciate your help!

    • AWeiss,

      Yes, this works for 99% of what you would need. User account A on the MacBook tells Dropbox that the location to store files is on the External Hard Drive. User account B tells Dropbox to store in on the internal drive, then uses Selective Sync like you said.

      There are only a couple of caveats people have run into using this approach:

      1. When you unplug the external hard drive, while logged in as User account B, Dropbox for User account A will crash. This is entirely expected, and is what you want to happen. It gives up and says “You removed the location where I’m syncing files! I give up!” and quits. That is much better than it saying “You removed all the files from the Dropbox folder, so now I will remove all of the files you stored on Dropbox!!!” YIKES – fortunately, that isn’t what happens.
      2. The other thing you might run into is that after a reboot, if you haven’t logged into the MacBook as User account A, Dropbox may not be started up, and won’t sync things to the external drive. User account B will be logged in, Dropbox will be running and syncing (using Selective Sync) but you might notice a discrepancy if you were to browse the external hard drive as User account B.

      I hope that makes sense, and good luck!

  29. Thank you for your reply, it makes sense!
    I have a few more questions though. I paused syncing because I am afraid I might run out of space on my internal HD, but there are still many more GBs to be synced. I will be getting my external HD (2TB) tomorrow. First of all would a large USB Flash drive be better than an external HD? Also I am thinking to uncheck ‘Start Dropbox on system startup’ in Dropbox preference in both mac accounts. Normally I just put my mac to sleep at night and don’t shut down, but I am usually logged in on one of the accounts, where I have to log out of in order to be able to log into the other account. Would it be best just to keep everything running( put to sleep at night) with the external HD mounted? Should I have to reboot, I would log into user account A first and launch Dropbox, then log out, log into user account B and launch Dropbox there on the internal HD with the select sync?
    Also it looks like it is taking days to sync the shared folders (about 80GB). Will it take just as long to move my Dropbox over to the external HD?
    This is all quite new to me, as you probably can tell.
    I am so grateful for your help. Thank you!

    • AWeiss,

      It sounds like you are asking how to get everything started, if you don’t already have all of your Dropbox downloaded and syncing somewhere.

      So if that is the case, I would start by logging into the User account A, the one that is going to mount Dropbox on the External Hard Drive and let it sync everything. You might want to adjust your power settings so that the computer stays on until everything is downloaded, or install an app like Caffeine or Amphetamine that will just make sure your Mac stays awake.

      Another thing to note is that you don’t have to “Log out” to switch over to User account B while User account A is downloading all of the Dropbox contents. On the Mac, go to System Preferences, Users & Groups, then click Login Options, then enable “Show fast user switching menu”. With this enabled, in the top right corner of the screen, you’ll be able to switch over to User account B without logging out User account A.

      If you start with this approach, then Dropbox should be on the external drive first. I would wait to run Dropbox logged in as User account B until all of the Dropbox syncing is done (or just log out of Dropbox if you already logged in).

      Once User account A has all of your Dropbox contents on the external hard drive, then you can log into User account B, log into Dropbox, and tell it to install Dropbox in your Home directory. Then go into settings and do two things:

      1. Setup Selective Sync and start with just one or two small directories while it is getting setup.
      2. Enable LAN Sync (so hopefully it will find Dropbox for User account A and just copy things from there)

      As for the USB thumb drive, you shouldn’t need it if you start with Dropbox all on the external drive.

      • Thank you again for all the valuable suggestions!
        Moving the Dropbox folder to the external hard drive seemed to have worked well. But now when I go into my Dropbox online I see every folder twice. Did I copy or move it over to the EHD? Do need to delete it from my home folder in my user account A, or unlink it in preferences( I think only used for selective syncing)? And it seems like all files need to be synced again!

      • Alexandra,

        I’m sorry you ran into a snag… It is hard to say for sure what happened from here, but the one thing that makes Dropbox great is that it keeps revisions of your changes to Dropbox! You might have simply made a duplicate of the folder, but I can’t say for sure. Depending on whether you have a free subscription to Dropbox or a paid subscription will determine how long they will hold onto the changes (I think it is up to a year for paid members).

        If I were in your shoes, I’d make sure that your Dropbox client on your MacBook is done syncing for both User account A and User account B. Once those are done, I’d completely shut those down to avoid any confusion and go directly to and try to sort it out from there. More than likely it treated a folder as a duplicate and just made a copy, but it would be safest to do that through their website so you aren’t accidentally deleting files (when deleting files on the website, you have to be pretty explicit).

        Hope that helps – and good luck!

  30. Thank you again approductive! So far so good.
    I was able to delete all the duplicate files in my Luckily they were all marked with an underscore_ in front of their file name. My mac user account A now has the Dropbox app on the EHD ( deleted it off the internal hard drive) and mac user account B only has selected files in the Dropbox app. I hope Dropbox on the EHD will recognize the changes I will be making to my Dropbox in my mac user account B.
    Keeping my fingers crossed, that this set up works well for what I need it to do!
    Thank you for all your help!

  31. I have everything set up and synced properly with both user accounts as you describe. My question is this: The 2 folders I have turned off in selective sync is ‘music’ and ‘photos’. These are synced on the external usb hard drive due to their large size. Can I access these from my primary log in using itunes and lightroom if I map them to look at the ext hd when connected? What happens when music/photos are added or modified? Will the changes sync back to dropbox even though I’m working with the files from my primary log in where these 2 folders aren’t synced?

    • Bob,

      Good question! Yes, if you are logged into your MacBook account that has Selective Sync turned on, you’ll still be able to view the external hard drive that has all of your Dropbox in it. So yes, you could point iTunes to the external hard drive for music and Lightroom for Photos. The only caveat is that if you open iTunes or Lightroom when your laptop is disconnected from the external hard drive, I’m not sure what will happen – they should just say “I don’t know where that drive is” but they might also freak out and try to load the stored library or something. It might be worth testing opening those apps after the hard drive gets disconnected to be sure.

      • Sorry for the delayed response approductive, but I wanted to let you know everything is working great. If photos or music are updated, those changes do indeed sync successfully back to dropbox when the ‘dropbox’ user account is logged in. This solution is working great for me, thanks so much for documenting this solution!!

  32. Lol because I am already doing this – was hoping there was a better way because I am already over 128g. Good article though!

  33. I have been using your method for over a year now, and no problems to report. In fact, I recently upgraded my transcend jetdrive lite from 128 to 256 gb and so have over three times the original 128 gb of storage on my MacBook Pro.
    I am considering moving from Dropbox to iCloud, simply because the latter has a more flexible pricing structure. I don’t need 1TB of cloud storage, about 200 Gb would suffice and iCloud would be considerably cheaper. Do you think the same method might work as yours, or would I have to find another solution?

  34. Thank you for your detailed investigation. Your idea with multiple users helped me a lot 😉

    Another thing, you mentioned the following: “If you plan to migrate your Dropbox from a USB drive to a Micro SD card, don’t do what I did and try to copy all of the files manually. […] it will say “There is already a Dropbox folder there” and you’ll have to delete the folder.”

    There’s a trick here:
    1) Copy all your files to the sd card in a folder named “Dropbox2”
    2) Let Dropbox create the “Dropbox” folder on the sd card
    3) Exit Dropbox
    4) Remove the new folder created by Dropbox and rename “Dropbox2” to “Dropbox”

    When you start Dropbox again it will still go through your files, which might take some time, but, at least you don’t have to start over copying everything again.

  35. The original post advice (set-up a new Mac user connected to Dropbox) worked PERFECTLY for me, much thanks! Just synced 500GB from external drive over the weekend with impacting my main share.

    I plan to try out Robert Jacobi (@RobertJacobi) advice for using Terminal and remote user.


    • The external drive should contain your Dropbox, not the other way around. If you move Dropbox to the external hard drive, what you see on should be the same as it always was.

      • Hmmm, right… I corrected that, and now see the DB folder on the first level of the external, and the DB folder is empty.

        Is the external drive now being backed up on the DB site? If so, where is it?

        Oh, yes. I’m doing this on my iMac.

        Thanks for your patience.

  36. Ahh, yes. My external disk already had a lot on it, and the DB folder is on the same level with those folders. I have now put those folders inside the DB folder, and everything is populating.

    Suggestions –
    you might alter you original instructions to say, ‘…change the Dropbox root location to your external hard drive, AND MAKE SURE EVERYTHING ON THE EXTERNAL DRIVE IS WITHIN THE DROPBOX FOLDER.’ Or something like that.

    Also, in your Benefits, you might alter; ‘With your external drive mounted, you can now see THE CONTENTS OF BOTH THE INTERNAL AND EXTERNAL DRIVES WITHIN YOUR HOME DROPBOX FOLDER’ or something like that, too.

    Again thanks very, very much for writing this and for maintaining the thread.

  37. The reason your SD card slot transfer speeds are so slow is that the MacBook Pro’s SD card reader is abominable. Most SD card readers support the UHS-I bus interface which tops out at a theoretical maximum of 104MB/s read speed. Note that that number is NOT write speed. According to Anandtech, Quick Bench was run on a 2011 MacBook Pro, resulting in read performance of 80MB/s and write performance of a paltry 10MB/s. The 2012 MacBook Pro with Retina display achieved 80MB/s reads and 40MB/s writes. Compare that to the theoretical 750MB/s of a typical SATA III hard drive, we’re talking 19-75x faster speed difference! Apple killed the SD card slot in the latest MacBook Pro’s, so the only option is an external drive. If still wanting to go the SD card route, definitely invest in the latest UHS-III cards and readers which support 624MB/s, approaching SATA-III speeds.


  38. Thanks for post and advice. I am working on a laptop that belongs to the school I work for so I am trying to gain access to all my teaching files with minimal storage on my device. As others have mentioned, I use an External HD and have lots of daily files (19 GB) I need to get to and then larger media files I only access once or twice per year. That drive currently has about 1/2 TB on a 2 TB drive but I will add more as the years go on.
    1. I need to be able to make changes to files and/or add new ones and have them saved externally to my DB folder so I can avoid having multiple saved copies floating around.
    2. I need to periodically backup all my changes to my external HD so I have a local copy should my internet access get interrupted.
    3. Regarding Google Drive, I need to move any files I create or are shared with me from Google Drive to DB so I own them separately.

    I am thinking your first approach creating multiple users on my laptop might be the solution but I often find I have files on my desktop or download folder that need to be filed properly. I can always get to everything via the website, but I wonder if the two user method will interfere with my workflow requiring me to login and logout many times to manage access to files.
    What are your thoughts?

    • The two-user method works so well because when logged in as yourself, you can use Selective Sync and have on your hard drive only what you need. But it gives you the advantage of an external hard drive that contains all of your Dropbox. On a Mac, you’ll see this in /Volumes/the_drive_name and typically the drive will show up on your Desktop.

      With the two user method, you don’t have to log into your Macbook as the other user unless the Dropbox application needs to be restarted. It sounds like this would work fine for you. One way to test it would be to create a throw-away folder on your external hard drive called something like “Dropbox Test Folder”, then as the Dropbox Mac user, setup Dropbox to sync inside that folder. Maybe do a Selective Sync just to try it out and get familiar with it.

  39. I have tried to get it to Sync to my external micro SD card on my PC, but it says error, folder is external. It is on a windows PC and the drive in exFAT. Is there anything I can do?

    • I do not have a Windows machine to test this on, so I can’t say for sure. My only guess is that Dropbox put something in place to prevent it from being synced to an external drive, but I’m not sure. Hopefully someone reading the comments will be able to offer a solution.

  40. As your instruction, it worked perfectly on my MacBook Pro 3 weeks ago, even the practice of plugging or plugging the external drive.
    However, I accidentally unlink the external HD when starting to open the user “Dropbox” today. When I try to reinstall the Dropbox again in user “Dropbox”, I can’t change the Dropbox location to my external HD. The message “Error with selected folder. This folder already contains a Dropbox directory” is always pop up.
    I go back to my main user, I can see the dropbox content in my external HD, but it couldn’t sync anymore.
    Please help me how to solve this problem. I do appreciate your thoughts.

    • The only way I know to fix this is to completely remove the Dropbox folder, and then setup Dropbox fresh. It would have to download all of the content again. There might be an easier way to do this, but I haven’t run into the problem so I’ve not had to walk through it… 😦

    • I had this same issue when I moved to a new Mac, and already had a Dropbox folder on my external drive was moving.

      I solved it by RENAMING (not removing) /Dropbox on external drive, I then allowed Mac Dropbox app to create a new /Dropbox folder, but I unchecked all folders files, so nohting was synced. I then stopped Dropbox, swapped two folders so my original was back to /Dropbox, and then started Dropbox again. It took a while to verify all files were synced, 2 hours, but it worked!

      • Hi Jon,
        I followed your instruction. It worked, but besides creating the original file folders, the Dropbox also duplicated many new file folders under the label as “file folder name (Selective Sync Conflict)” in the external HD. And the Dropbox account on the website also had the same happened after syncing.

        Since it made me a lot of confusion to use my Dropbox file folders, I go back to use the instruction of “approductive” by removing all the Dropbox file folders in the external HD and on the website. Then I setup Dropbox fresh on the external HD. Although it needed time for syncing all of the contents, it worked perfectly now.

        Thanks for your ideas and also very appreciated the “approductive”‘s help.

  41. Hi there,

    I just wanted to advise caution to anybody having shared Dropbox folders. My Mac has very little memory as it is and I have a gigantic Dropbox folder which is shared with my co-workers, so I changed the destination of the folder in my Dropbox settings to an external drive, which I was planning on leaving permanently connected after reading this page, to clear up space. I didn’t copy the folder or drag it on Finder – I changed the location in the Dropbox preferences. As far as I could tell it had gone well and I only had one copy of the folder at the end of the process. The reality is that over 5000 files were corrupted when they were stored in the external drive (which is new) and were renamed with the prefix “.-“. It seems like other people have had this issue when installing Dropbox on an external drive:

    I thought the main concerns Dropbox had with external drives had to do with them being disconnected or inaccessible, and that by having the drive permanently connected to the computer there would be no problem.

    So let this be a word of caution to not do this if you have shared files, unless you understand the explanations on the thread above, everyone is on board and you really do know how to proceed.

    It seems like a much preferable solution (and the one I should have considered before putting other people’s work at risk…) is, if you do not need access to all of your files at all times, to selectively sync only those folders which you do need on a regular basis, and store the rest on the cloud.

Let me know if you try it...

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