When using the Mac system, often encounter the connection on the mobile hard disk, you can see the contents of the disk, but could not write the case, reported read-only file system error, then you may be the most easily think of the method is to install the appropriate software, such as NTFS for Mac and so on, However, the general situation will encounter license problems. This approach, which is introduced today, operates on the command line, and if you don't want to pay for the software and do not want to use piracy, try this approach. In fact, those apps are just the command line based on the addition of a layer of UI, the use of more convenient and beautiful, the principle is actually the same.
Hardware and Software Environment
Macbook Pro MGX 72
OS X EI Capitan
View device number
$ mount
Uninstall device
Because the system mounts automatically when a mobile hard disk is connected to a Mac, you need to uninstall from the default mount point first
$ sudo umount/dev/disk2s1
Re-mount
Create an empty directory, then mount the device to this directory, and then you can move the hard drive at will
$ mkdir MNT
$ sudo mount_ntfs-o rw,nobrowse/dev/disk2s1 mnt