Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

Partitioning my External Hard Drive

I want to partition my External Hard Drive. I have erased and Formatted it to Mac OS Extended (journaled) and the partition option in Disk Utility is still greyed out. I have run Terminal command:


diskutil erasedisk hfs+ External GPT /dev/disk2


but I get this message:


Error: -69877: Couldn't open device


Can anyone help?


Thank you!

MacBook Pro Retina

Posted on Mar 28, 2020 6:17 AM

Reply
Question marked as Best reply

Posted on Mar 28, 2020 6:37 AM

Mikeymusic89 Said:

Partitioning my External Hard Drive: I want to partition my External Hard Drive. I have erased and Formatted it to Mac OS Extended (journaled) and the partition option in Disk Utility is still greyed out.[...]

———-


Try these Methods to Troubleshoot this:


How Else to Attempt this Format:

See if this becomes readable by:

  • Using Another Mac (or even a Windows PC), as permissions may be in the way somehow
  • Booting into Safe Mode (Hold Down “shift” upon boot), in which unnecessary items are placed aside, and fixed are made toward a success it log In
  • Removing Security Software, as it may have become encrypted
  • Creating a new Administrator, seeing if you can perform this in that account. If so, then it is something misconfigured in your current user


Read/Write Errors:

Your hard drive may have become damaged/unusable, and if that is the case then, contact the manufacturer for assistance. Note that data recover can be quite pricey at times. That’s just the way it is :(


Format Type:

Verify that the format-Type is readable by your version of Mac that you are currently using.

5 replies
Question marked as Best reply

Mar 28, 2020 6:37 AM in response to Mikeymusic89

Mikeymusic89 Said:

Partitioning my External Hard Drive: I want to partition my External Hard Drive. I have erased and Formatted it to Mac OS Extended (journaled) and the partition option in Disk Utility is still greyed out.[...]

———-


Try these Methods to Troubleshoot this:


How Else to Attempt this Format:

See if this becomes readable by:

  • Using Another Mac (or even a Windows PC), as permissions may be in the way somehow
  • Booting into Safe Mode (Hold Down “shift” upon boot), in which unnecessary items are placed aside, and fixed are made toward a success it log In
  • Removing Security Software, as it may have become encrypted
  • Creating a new Administrator, seeing if you can perform this in that account. If so, then it is something misconfigured in your current user


Read/Write Errors:

Your hard drive may have become damaged/unusable, and if that is the case then, contact the manufacturer for assistance. Note that data recover can be quite pricey at times. That’s just the way it is :(


Format Type:

Verify that the format-Type is readable by your version of Mac that you are currently using.

Partitioning my External Hard Drive

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.