I recently got hold of a Toshiba Canvio 3TB external hard disk drive and was trying to format it using Disk Utility. To my surprise, I encountered a rather weird error that mentioned MediaKit not having enough space to perform the operation. The exact error message being,
MediaKit reports not enough space on device for requested operation.
Though it initially felt like my brand new HDD was a waste now, the solve was not really rocket-science – rather pretty straightforward. So before I tell you how to fix this, let’s first try to understand what the error really meant?
What’s the cause?
This type of error is generally caused when your EFI partition is below 200 MB. Mac requires an EFI partition of at least 200 MB to perform any Disk Utility function on an HDD. If your drive came factory formatted in NTFS, chances are your EFI partition would be lesser as Windows can work with a minimum of 100 MB.
What is EFI partition you ask? Well, the EFI system partition (ESP) is a small partition formatted with FAT32, usually 100 MB, which stores the EFI boot loaders for the installed system and applications used by the firmware at startup.
So how to fix this?
Before we begin,
Please note that all data on the HDD will be lost. I do not take any responsibility whatsoever in the unlikely event that your HDD gets bricked. By following these instructions, you agree to take full responsibility for the consequences.
Alright, now let’s fire up Terminal to get the name of the HDD you are trying to fix. Type the command below to list down all drives. Look for the label “external, physical” and note its Identifier. In my case it’s disk2. Could be different for you.
Now let’s force unmount the disk (and all volumes on it) by typing in,
diskutil unmountDisk force disk2
And then write zeros to the boot sector by typing in,
sudo dd if=/dev/zero of=/dev/disk2 bs=1024 count=1024
You will be asked to enter your administrator password. Go ahead and do it. Note that entering a password in Terminal will cause your cursor not to move. Your input will be accepted anyway.
Finally, let’s go ahead and partition it. Again, in my case it’s disk2. Could be different for you. Type in,
diskutil partitionDisk disk2 GPT JHFS+ "Canvio" 0g
Where Canvio is what you want to name your HDD. This will also format your drive and make it ready for use.
That’s it, you are done! Do share your feedback/experience in the comment section below.
If for some reason, you are asked to enter your password again when performing basic functions on the HDD (like creating folders), unmount and then mount the disk again. That should resolve any issues.