So you’ll need to find a computer that can reformat the drive to exFAT. Firstly, iOS itself provides no way to reformat hard drives. There are two pieces of bad news however. exFAT is a good alternative that both iOS and Windows can understand without hassle, while retaining support for large file sizes. To use it with an iOS device you’ll need to change that. Your external hard drive is likely to be formatted in the Windows-friendly NTFS format.
If your drive is formatted according to a standard which iOS doesn’t support, you won’t see the drive pop up at all!
Except, there’s no such thing as a universal file format.
It’s like books in a library arranged according to the Dewey Decimal System. Formatting is the process of arranging the space within the drive according to a system. Hard drives and flash drives need to be formatted before you can use them.
