#Format external hard drive mac error how to#

On the pop-up dialog box, type the name of the formatting drive.Select the external drive from the sidebar and click the Erase tab.Go to Finder > Applications > Utilities > Disk Utility.If the external hard drive is in NTFS format, erasing it to a macOS compatible file system format should fix the read-only issue.Įrase the external storage drive, as follows: Warning: Back up the files on the Mac external hard drive before erasing it.

#Format external hard drive mac error how to#

How to Resolve Mac External Hard Drive Read-Only Error? Formatting Error: If the external hard drive is not erased correctly and has formatting errors, then macOS may mount the drive but may not allow writing data on to it.Permission Settings Issue: If your macOS could not recognize the access permission settings for your external hard drive, then the system will either prevent access or provide read-only permission to the external hard drive.NTFS is the proprietary file system of Windows and is not compatible with macOS. Mismatched File System: If your external hard drive is in the NT File System (NTFS) format, then macOS treats the drive as read-only.Reasons for an External Hard Drive ‘Read Only’ State So, what might be the reasons behind this read-only state? The following section describes in detail. If the drive is in read-only state, then you can only read data from the drive, but cannot write data on to it.