I'm trying to share an external hard drive through lan file sharing (SMB). The sharing works for folders and file in my Macbook. I have set up a “Sharing” account that I give access to the files I want to share.

The problem is that the “plus” button to add a user with access to that folder is greyed out when I select the hard drives, so I cannot add my file sharing account. And the users that already have access cannot be edited, they're also greyed out, as is the minus button. Basically I cannot edit anything.

I have also tried using my administrator account since that one is already added to the folder's users with access list, but I cannot make SMB work with that account.

The hard drives are in ExFat and Fat32 formats. I know I can share them through my WiFi router, but I need to share them through my Macbook.

I tried adding my Sharing account to the Permissions box on the Get Info dialogue, but PathFinder didn't let me save the changes (it didn't give me a reason), and Finder just says that “You can read and write” but doesn't show me any other options to add, subtract, edit or see other users with access.

I don't know if this is a sharing issue, a permissions issue or both.

So, is sharing an external hard drive possible? If so, what am I missing?

  • 1
    You’re asking to share a physical device using a file sharing protocol. This is like asking if Uber can help you share title ownership of the car you want to ride in. What exactly are you trying to accomplish with this proposed action?. As written this sounds like an XY Problem.
    – Allan
    Dec 31, 2019 at 11:01
  • 6
    @Allan The OP has external drives connected to their Mac, and would like to share their content via SMB. Maybe I'm missing something here, but IMHO this is exactly the purpose of a file sharing protocol.
    – nohillside
    Dec 31, 2019 at 12:53
  • @nohillside: Allan is correct. You can't share drives using SMB. SMB is a networked filesystem, its purpose is to share files and directories. If you want to share a drive, you need a different protocol, something like DRDB. Sharing a drive and sharing files on a filesystem on a drive are two very different things. Jan 1, 2020 at 9:36
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    @JörgWMittag Let‘s assume I‘m aware of that difference. Let‘s also assume that the answer below explaining how to share the content of a whole drive (aka the root folder) via SMB/AFP is correct :-)
    – nohillside
    Jan 1, 2020 at 10:08
  • @Allan I want to access the content of my hard drive in my Android phone. And I cannot share the drive through my wifi router, because I'm not the only one with access to it. So I was thinking of doing it through my computer.
    – Tir Dy
    Jan 1, 2020 at 15:26

2 Answers 2


To add to @nohillside answer you can share a FAT32 formatted drive but not set permissions as the filesystem doesn't support it.


If you want to control access to files on the USB by permissions then format it using a filesystem that supports it (such as HFS) and changes will be avaliable in File Sharing.


  • I see, thanks. But how do I go about accessing that shared drive? It doesn't show up when I access with my admin or guest accounts.
    – Tir Dy
    Dec 31, 2019 at 15:26
  • @TirDy - where doesn't it show up? Do you mean you can't see it in your Mac File Sharing? Or you can't connect via SMB from elsewhere? I can connect from Windows to the FAT32USB share in top picture (after disabling Mac firewall) - see this screenshot. Please edit your question to add a picture showing where you mean.
    – lx07
    Dec 31, 2019 at 16:22
  • On Preference's File Sharing my Hard Drive shows just like yours does in your screenshot. Admin, Staff and Everyone have access. I mean it doesn't show up when I try to access it from my android phone. My other shared folders (Movies, Download, Documents... I can access them by setting a path to Download or Documents. I have tried setting the path to my hard drive as Volumes/HardDrive and Hard Drive, but neither worked.
    – Tir Dy
    Jan 1, 2020 at 15:18

ExFAT/FAT32 don't support file/folder ownership, so you can't assign access rights or users to them (neither for local use nor for sharing).

  • 1
    You might add that sharing is still possible - to answer the question "So, is sharing an external hard drive possible?" properly - but all remote users have full access (if guest user sharing is enabled even a guest has the same full privs). ;-)
    – klanomath
    Dec 31, 2019 at 14:04
  • @klanomath I was still looking into this but lx07 already posted an answer now :-)
    – nohillside
    Dec 31, 2019 at 14:06

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