I have a 150GB USB external hard drive (IDE/Parallel ATA disk in an enclosure) which was formatted as one partition, FAT32 in Windows XP. I wanted to extract the files off of it using my Macbook Pro running Apple Macintosh Leopard (Mac OS X 10.5.6).

However, when I plug it in, I get a dialog box which says:

Disk Insertion
The disk you inserted was not readable by this computer.
Initialize…   Ignore   Eject

I saw many references to there being a 127GB or 128GB partition limit for FAT32 for Mac to successfully mount.

Also, a potential problem was that when using Disk Utility it shows up on my system incorrectly as formatted as a Windows NT Filesystem (NTFS-3G).

diskutil list disk3

Output:

/dev/disk3
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:     FDisk_partition_scheme                        *149.1 Gi   disk3
1:               Windows_NTFS                         149.0 Gi   disk3s1

It did however mount automatically and show up when I was running a virtual machine, for example Parallels and Windows XP (I used VirtualBox and Windows 7), but copying over files this way proved to be very slow.

So, after spending a lot of time on the internet looking for solutions, I just tried mounting it from the Terminal (command line) with success!

First, make a mount point:

sudo mkdir /Volumes/EXT_HD

Now mount (your device numbers may be different, e.g. /dev/disk2s1 — you can determine what it is as it will the the highest number when you issue the command ‘ls /dev/disk*’):

sudo mount -t msdos /dev/disk3s1 /Volumes/EXT_HD/

It eventually showed up in Devices in Finder, but just to let you know, when I tried ejecting (unmounting) it when I was done, even though I had closed all programs I got the error:

The disk “USB_DRIVE” is in use and could not be ejected. Try quitting applications and try again.

Unmounting via he command line also failed:

sudo umount /Volumes/EXT_HD/
umount: unmount(/Volumes/EXT_HD): Resource busy

So I had to reboot.

I hope someone finds this information useful because I sure didn’t find any help…

EDIT (01 Oct, 2009): Apparently there is a way to enable native NTFS read/write support in 10.6 Snow Leopard (and this may work for Leopard). However, I would recommend not allowing write ability (and thus read only) when using this method as it may corrupt your NTFS files. To set to read only, follow the directions in the link but instead of using ‘rw’, use ‘ro’, e.g. UUID=123-456-789 none ntfs ro

In Mac OS X 10.4 Tiger, you could use Finder (GUI) to mount an SMB mount which was being tunneled through ssh
For example:

• From Terminal establish the tunnel:

  ssh -L 139:remote_machine:139 user@remote_machine

• Then, in Finder, Go ? Connect to Server…
• In “Server Address”, smb://localhost/mountpoint

However, this doesn’t work in Mac OS X 10.5 Leopard anymore!
The workaround is instead of using Finder, to use the mount_smbfs command in Terminal:

mount_smbfs //samba_user_name@localhost/samba_share /local/mount/point/

For example:
After establishing the tunnel (see above), I first made a mount point:

cd ~; mkdir sambamount

Then mounted it:

mount_smbfs //samba_user_name@localhost/data ~/sambamount

Once mounted, you should see the volume appear on your desktop, and you can drag it to the trash (or use ‘umount’) to unmount it.

**** UPDATE 25 Mar, 2009 ****

I’m getting many hits for this post, so I’m adding a little more detail for my setup specifically.

My work blocks almost all ports to incoming traffic. In order to log into a machine from the outside (for example from my home computer) I must first ssh into a firewall computer and setup a tunnel, or can ssh or telnet to another computer (you can do nothing on the firewall computer except ssh or telnet).

So, here’s my setup for tunnelling the SMB traffic within a ssh session (and still mount via Finder):

home <-ssh/tunnel-> firewall.example.com <-smb traffic-> smb_server.example.com

My work account credentials are the same on both the firewall computer and the SMB server.

You can add your modified version of the following to the file ‘/Users/mac_username/.ssh/config’:

#------------------------------------------------------
# For mounting smb shares locally from home:
#-- This is the name of this alias to this specific
#  configuration:
Host smb_tunnel_from_home

#-- Work's firewall computer (can also use IP number here)
Hostname firewall.example.com

#-- In place of 'work_username', your firewall username goes
#  here:
User work_username

#-- 127.0.0.2 is your computer, the second (where there are
#  x's) is the SMB server. Seems like I have to use the IP
#  number (instead of smb_server.example.com for this!):
LocalForward 127.0.0.2:139 xxx.xxx.xxx.xxx:139
LocalForward 127.0.0.2:445 xxx.xxx.xxx.xxx:445

#------ TO USE: ------
#--Using Terminal, at the prompt type (this creates an alias
#  of 127.0.0.1 at 127.0.0.2):
#    sudo ifconfig lo0 alias 127.0.0.2 up
#--Now start the ssh session:
#    sudo ssh work_username@smb_tunnel_from_home \
#    -F /Users/mac_username/.ssh/config
#--Then, in finder, Go->Connect to Server (Cmd-K), in the
#  box type:
#       smb://127.0.0.2/work_username
#--In the box which pops up, enter your work_username
#  and work_password.
#--Be sure to unmount the volume in finder when done using.
#------------------------------------------------------