I'm giving my macbook air to my son, and want to erase all content and install a new OS. When trying to erase the disk with disk utility I get the error message (couldn't open device")
I have Mojave installed. MacBook Air 2013.
MacBook Air 13", macOS 10.14
Hi rafael40,
Were you booted from macOS Recovery when you tried to erase your Mac? Your Mac won't allow itself to be erased normally since you can't erase the drive you're booted from.
If you're looking to just erase the startup volume, which contains your Mac's data (or its APFS container), local macOS Recovery will work fine for this (Command-R). However, if you want to erase the entire drive, you must boot macOS Recovery over the Internet by holding down Option-Command-R at startup (AFAIK).
Instructions for erasing your Mac can be found here: How to reinstall macOS from macOS Recovery - Apple Support
Hi rafael40,
Were you booted from macOS Recovery when you tried to erase your Mac? Your Mac won't allow itself to be erased normally since you can't erase the drive you're booted from.
If you're looking to just erase the startup volume, which contains your Mac's data (or its APFS container), local macOS Recovery will work fine for this (Command-R). However, if you want to erase the entire drive, you must boot macOS Recovery over the Internet by holding down Option-Command-R at startup (AFAIK).
Instructions for erasing your Mac can be found here: How to reinstall macOS from macOS Recovery - Apple Support
Thanks, it worked fine!
I'm trying to erase the disk, and get "couldn't open device" error message at disk utility
