So that may be the reason why the 'Erase' and 'Partition' tabs of Disk Utility are grayed out for your SD card.Īnd to check this simply check the format of this disk in Disk Utility! That's to say, you can't perform any input operation to this disk, including re-partition. As the article Partition external drive greyed out in Disk Utility I've seen, it says NTFS file system is read-only on Mac computers. Since this issue involves MBP and read-only, the first idea I got is that: is this SD card formatted with the NTFS file system? As we all know that NTFS formatted drive is read-only for macOS.
