Share Mac external HDs with Windows

Q. I have a MacBook and a couple of PCs. I also have an external 1TB drive on my Mac. I can mount the Mac’s internal hard drive on my PCs but I cannot mount the 1TB hard drive. Is this possible?

A. One of the cool things about Macintosh computers is that we’ve always been able to read data on Windows drives and floppy disks. In the past there were utilities to that enabled Windows computer to run AppleTalk protocol and read Macintosh volumes.

Mac OS X includes Samba which allows users to run SMB (Server Message Block) protocol. SMB was developed by IBM, but has been highly modified by Microsoft. The open source Samba has reverse engineered SMB to provide a version for non-Microsoft systems.

By running SMB on your Macintosh you can share your files with your Windows neighbors. Go to System Preferences -> Sharing and check Windows Sharing. Then PC users can add your Mac to their Network Places or “map” your drive as a network drive by adding \yourIPaddressvolumename.

The problem with external drives is that they are not automatically included in the smb shares. When you enable “Windows Sharing” a configuration file is written to the Unix file system. Most configuration files are stored in the “etc” directory and there you’ll find the “smb.conf” file.

So once again open the Terminal (Applications -> Utilities -> Terminal) and at the prompt enter “cd /etc” and press enter – to “change directories” the “etc” directory. You need to be an administrator to edit the file and you should begin by backing up the file. Enter “sudo cp smb.conf smb.bak” at the prompt to make a copy of the file. “sudo” is a special command that lets you act as an administrator for a short period of time.

Check that you’ve made a copy by listing the files with “ls –la” and Return. You should see both the original and the backup. Now edit the file with “ed”, “vi” or “pico”. With pico the display is similar to most text editors and the commands are at the bottom of the file. Enter “pico smb.conf” and scroll to the bottom (with Control V) and add the following to the bottom of the file:

path = /Volumes/LaCie_d2_156_GB
valid users = tmitra
writeable = yes

In the example above my “Share name” is “LaCie” – this is what the PC user will see. The Macintosh name of my drive is “LaCie_d2_156_GB” – note that I have replaced the spaces with underscores. The “valid user” is the name of a user on my Macintosh and “writeable” means that I can read and write to the drive.
Now on the PC go to “My Computer” and choose “Map Network Drive” from the Tools menu. Then in the dialog enter the Mac’s IP as the server and the share name:


Then enter your username and password and the volume should be mounted. You can then copy files to and from your PC – and share them with the Mac.

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