Hi. I have a 6tb external drive that was previously connected to a pc. I connected it to my mac, reformatted to exfat, but now it is showing up as 750 gb only. Disk utility shows 1 partition on the drive. I have added the drive to spotlight exclusion and removed it, and that has not foxed the issue. Any help would be appreciated. Thanks
macOS does not always properly recognize partitions created by other operating systems. Sometimes you may even need to write zeroes to the beginning of the drive to destroy the existing partition table before macOS will be able to properly recognize and erase the drive.
In addition, macOS 12.x Monterey may still have some compatibility issues with some USB3 drives. If this is the case, then try disconnecting all other external devices in case one of them is interfering with the drive. If you are using a USB-C Mac, you can also try using the USB-C charging cable or connecting the drive to a USB2 hub which supposedly allows some USB3 drives to work with Monterey although the transfers will be extremely slow.
Plus Disk Utility beginning with macOS 10.13+ now hides the physical drive from view by default so you may only have erased a portion of the physical hard drive. Within Disk Utility click "View" and select "Show All Devices" so that the physical drive appears on the left pane of Disk Utility. Select the physical drive which should be identified by its make & model or perhaps identified by the chipset used in the USB adapter, drive dock, or enclosure. Erase the whole physical drive as GUID partition and exFAT. The "GUID" partition is critical for large drives.
Edit: Also try connecting the drive directly to the Mac. As others have mentioned the USB adapter, drive dock, or enclosure also needs to be compatible with a 6TB drive. Many older model adapters/docks/enclosures are not capable of properly working with a large drive so the drive may appear as having only a very small usable storage space (don't use the drive with that adapter/dock/enclosure since you may lose data).
macOS does not always properly recognize partitions created by other operating systems. Sometimes you may even need to write zeroes to the beginning of the drive to destroy the existing partition table before macOS will be able to properly recognize and erase the drive.
In addition, macOS 12.x Monterey may still have some compatibility issues with some USB3 drives. If this is the case, then try disconnecting all other external devices in case one of them is interfering with the drive. If you are using a USB-C Mac, you can also try using the USB-C charging cable or connecting the drive to a USB2 hub which supposedly allows some USB3 drives to work with Monterey although the transfers will be extremely slow.
Plus Disk Utility beginning with macOS 10.13+ now hides the physical drive from view by default so you may only have erased a portion of the physical hard drive. Within Disk Utility click "View" and select "Show All Devices" so that the physical drive appears on the left pane of Disk Utility. Select the physical drive which should be identified by its make & model or perhaps identified by the chipset used in the USB adapter, drive dock, or enclosure. Erase the whole physical drive as GUID partition and exFAT. The "GUID" partition is critical for large drives.
Edit: Also try connecting the drive directly to the Mac. As others have mentioned the USB adapter, drive dock, or enclosure also needs to be compatible with a 6TB drive. Many older model adapters/docks/enclosures are not capable of properly working with a large drive so the drive may appear as having only a very small usable storage space (don't use the drive with that adapter/dock/enclosure since you may lose data).
What model Mac and year?
How is the disk now connected to the Mac?
How was the disk connected to the Mac?
So disk utility only shows 750GB with no partitions?
What specific disk?
What specific enclosure if the enclosure did not come with the disk sealed into the enclosure?
D
Thank you. The GUID partition and exFAT suggestion fixed the issue.
Thanks for the update. I'm glad it worked.
Not recognizing correct hard drive size
