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How Do I Format External Drives?

Hello Gary I’m sorry to bother you.
I have just purchased my second iMac running High Sierra.
I dont understand when I’m formating a new external drive I have to select one of these settings and I do not know which to use on what.
1, Guid Partition Map
2, Master Boot Record
3, Apple Partition Map
If I was formating in say ExFat what would I have to choose, or Fat32
Guid Partition is for Mac OS Extended.
Thanks Gary and once again sorry to bother you
George Uzarowski
George Uzarowski

Comments: One Response to “How Do I Format External Drives?”

    6 years ago

    Are you going to just use this drive to store archive data or some other files? Then if you are going to only use it for Macs, don't use ExFat or FAT32, which are only useful if you also have Windows computers. Use HFS+ (MacOS Extended Journaled). But if you absolutely must be able to access it on a Windows computer then you are stuck with ExFAT or FAT32.

    Remember "access" means plugging it directly into a Windows computer. It doesn't mean accessing it from a Windows computer via a network while the drive is actually plugged into your Mac. Network access doesn't care about the drive format so only format the drive depending on what computers the drive will actually be connected to physically.

    The partition scheme doesn't matter for macOS, unless you plan to boot from that drive, in which case use GUID. But GUID works otherwise too, so just use GUID for Mac drives.

    However for ExFAT or FAT32, you apparently need to use Master Boot Record according to Apple (Partition a physical disk using Disk Utility).

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