I have a 4TB WD external hard disk that is partitioned as follows:

/dev/disk2 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *4.0 TB     disk2
   1:         Microsoft Reserved                         134.2 MB   disk2s1
   2:       Microsoft Basic Data NTFS                    3.2 TB     disk2s2
   3:       Microsoft Basic Data exFAT                   506.0 GB   disk2s3
   4:                  Apple_HFS TIMEMACHINE             272.9 GB   disk2s4

Time Machine app recognizes the disk and all the partitions but when it attempts to erase the partition a popup message appears saying "MediaKit reports not enough space on device for requested operation"

How can I fix this problem?

macOS 10.13.3 High Sierra


The problem is that Disk Utility isn't able to reformat your drive from NTFS to APFS. You can format it to HFS+, then Disk Utility will pick up and do the rest for you. Here is a tutorial with detailed, step by step instructions: https://mycyberuniverse.com/web/how-fix-mediakit-reports-not-enough-space-on-device.html

Summary of commands needed, in terminal:

diskutil list
diskutil unmountDisk force disk2
sudo dd if=/dev/zero of=/dev/rdisk2 bs=1024 count=1024
diskutil partitionDisk disk2 GPT JHFS+ "New Drive Name" 0g

Where disk2 is the name of your external drive, listed from diskutil list

  • Not sure, but isn't using R instead of 0g the right way? – pixelomer Mar 3 '18 at 11:42
  • @ÖmerRıfatKuldaşlı I think R and 0g will both fill the remaining space available. 0g worked fine for me! – Taylor Newton Mar 6 '18 at 19:42

Whilst nuking the drive (using dd) will work, it is the nuclear option that doesn't address the problem. The issue is that apparently you need an EFI partition of at least 200MB. An EFI partition is just a regular FAT32 partition with the boot flag set, so you might have to use GParted on a Linux recovery disk to arrange it (I'm sure its possible on the Mac, but I have no idea).


I had the same problem with media kit reporting ‘not enough space on device’. I used a Windows 10 installation usb stick to boot my MBP. If u follow the installation proces, there is a point where it ask you to create a clean install. Choose the clean install option. After that you can select drives/or partitions to install windows. At this point you can delete al partitions on the drive. That is what I did. I deleted al partitions and did not make a new one. After this I canceld windows installation and reboot MBP with MacOS install usb drive. Then I could format SSD without problems to MacOS extended journaled with GUID. Sorry for my bad English, but I hope it can help someone as it did helped me.



You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .