apple computer external hard drive read only

In the information window that pops up, go to the Sharing section and click the lock to authenticate. To set this option for external drives, select the drive on your desktop or in the Finder sidebar, and then press Command-I to get information on the drive. To prevent such errors from happening, OS X includes a setting to ignore permissions on external drives, so all files on the drive should be fully accessible regardless of their permissions settings. This may happen even though getting information on files and folders shows you ought to have full access to the drive. Since permissions are set up through account UUID and UID numbers, if the drive is used with different systems, it may have permissions associated with it for accounts that your current system does not recognize, or even odd permissions settings that can prevent access to the files on the disk or to the disk itself. To get around this, you can simply use Disk Utility to repartition and format the drive to Mac OS X Extended, provided the drive is only going to be used with a Mac, or format it to ExFAT or FAT, both of which are fully supported in OS X.īeing a multiuser operating system, OS X sets up access permissions for all files and folders on the system, including external drives, which are merely accessed as a folder once attached and mounted. To check if a drive is NTFS-formatted, open Disk Utility and select it from the sidebar, and you should see its format listed among other details at the bottom of the Disk Utility window. The drive's formatting can be seen in the information window as well as in Disk Utility, and clicking the check box at the bottom of the window will ensure the drive's permissions are ignored.

Unfortunately even though there are third-party drivers and workarounds to allow OS X to write to NTFS drives, these features are not supported by default, so such drives will only be mounted read-only. Often commercially available drives will be formatted to FAT32 and therefore be fully compatible with both Windows and OS X however, many popular drives (especially high-capacity ones) may be formatted to NTFS by default. The first detail to check is if the drive is formatted to the popular NTFS format used in Windows systems. Do you have an external hard drive that you cannot write to on your Mac? While most external storage media's default formatting and other setups should make them both readable and writable on most Mac systems, there may be times when this is not the case.

Apple computer external hard drive read only