![mac disk utility partition greyed out external hard drive mac disk utility partition greyed out external hard drive](https://appletoolbox.com/wp-content/uploads/2020/01/Disk-Utility-erase-window-with-name-format-and-scheme-options.jpg)
- MAC DISK UTILITY PARTITION GREYED OUT EXTERNAL HARD DRIVE PRO
- MAC DISK UTILITY PARTITION GREYED OUT EXTERNAL HARD DRIVE PLUS
- MAC DISK UTILITY PARTITION GREYED OUT EXTERNAL HARD DRIVE FREE
In the next steps I assume that the Device Block Size is 512 bytes. Get the block size of the external disk: diskutil info disk1 | grep "Device Block Size" In the next steps I assume the disk identifier of your external disk is disk1 Open Terminal and enter the following to get an overview: diskutil list
![mac disk utility partition greyed out external hard drive mac disk utility partition greyed out external hard drive](https://i.stack.imgur.com/EAV6E.png)
If you don't want to completely erase the drive you should be successful following the steps below: I think Disk Utility misses a proper EFI partition at the beginning of the disk. Does that mean that I need to create the new partition from a Mac?
MAC DISK UTILITY PARTITION GREYED OUT EXTERNAL HARD DRIVE FREE
I want to put encrypted Time Machine backups on the second partition that I create from the free space.
MAC DISK UTILITY PARTITION GREYED OUT EXTERNAL HARD DRIVE PLUS
Notice how the plus sign is greyed out so that I cannot create another partition with the free space. … of the physical disk in Disk Utility (notice how there doesn't appear to be any unallocated space on the disk to create another volume:
![mac disk utility partition greyed out external hard drive mac disk utility partition greyed out external hard drive](https://www.softwarehow.com/wp-content/uploads/partition-external-drive-mac3.png)
MAC DISK UTILITY PARTITION GREYED OUT EXTERNAL HARD DRIVE PRO
I took this drive over to my MacBook Pro running OS X El Capitan 10.11.3 and fired up Disk Utility, but for some reason it doesn't look like Disk Utility is seeing the free space, so I can't create a new volume. I verified this on my Windows machine: DISKPART> list diskĭiskPart shows 2 partitions - one 128 MB, and the other 1267 GB with 1526 MB of free space. The other part of my drive is 1.5 TB of free space. The drive is GPT, and I have two volumes on it (one volume is "Microsoft Reserved", other volume is NTFS). The erased volume is written seven times to ensure the data can't be restored.I have a 3 TB Western Digital red disk in a USB hard drive dock. Department of Defense (DOD) 5220-22M standard for securely erasing magnetic media.
![mac disk utility partition greyed out external hard drive mac disk utility partition greyed out external hard drive](https://cdn.osxdaily.com/wp-content/uploads/2012/02/repair-disk-boot-volume.jpg)
It erases the volume's data by writing over it with zeros.