You can select a new file system format from the drop down below, and also name the new volume to be created. You can select the physical disc you want to reformat in the tree on the left-hand side of Disk Utility. Be sure to copy any and all file from the drive as all the data on the drive will be erased. You are about to format your storage device. Highlight the physical drive you wish to reformat and on the menu at the top to the right select erase. Each physical drive is shown with the partitions of that drive nested below. In the left-hand side inside of Disk Utility you will see a list of all the connected hard drives. You can reformat a hard drive on Mac OS X by using Disk Utility. This can be a simple task or a long undertaking depending on the size and usage of the storage device, but is a necessary and important step. However, making your storage device Mac compatible, and even cross compatible with Macs and PCs, is as simple as reformatting the drive.įirst and foremost before proceeding any further, you are about to format your storage device. Many storage devices such as USB drives and external hard disk drives come pre-formatted in NTFS because a larger number of consumers are using them on PCs. The cause of the 'Read Only' behavior is due to the format of the file system. While this file system is readable on Macs because OS X can rearrange the data as it is reading it, the way that NTFS writes the files to the storage device is not hence, you can read, but not write. The NTFS file system is a system specifically optimized for Windows in the way that it organizes the data on the drive. If you look in the general twirl-down under format you can see that this drive is formatted in the windows NT file system. The cause of this is due to the filing system the storage device is formatted in. Looking in the info window you can see that the permissions for the drive only allow for reading.

If you right click the drive and select Get Info, you can see at the bottom of the info window under the sharing and permissions twirl down, you only have permission to read from this drive and nothing else. Trying to copy a file to my USB drive gives an icon indicating that you cannot copy files to the volume. Something is obviously not right with the storage drive.

If I try to delete a file, by pressing Command+Delete, nothing happens and, if I right click the file, the option to move it to the trash can is missing. But if I attempt to copy a file to the drive on my Mac, I get an icon telling me that I am not able to copy the file. I am able to open the drive and can even copy files from the drive. I have a USB drive that I purchased and use with various PCs at work and school. Quick Tip: Solving “Read Only” External Drive Problems on Your Mac Quick Tip: Solving 'Read Only' External Drive Problems on Your Mac

Usb drive that works with mac and pc