Creating an installer on MacOS doesn't create EFI partition

CandyManOfficial · May 27, 2023

I was following the guide to creating an installer in MacOS, which downloaded without incident. The only problem is that it created a disk image called "Shared Support". My actual disk (which is called Install MacOS Ventura) doesn't have an EFI partition whereas "Shared Support" does. The EFI partition on Shared Support appears to be a read only file system so I can't make an EFI folder for it. How can I resolve this? I can't seem to change the permissions of Shared support...

EliteMacx86 · May 27, 2023

CandyManOfficial said:
I was following the guide to creating an installer in MacOS, which downloaded without incident. The only problem is that it created a disk image called "Shared Support". My actual disk (which is called Install MacOS Ventura) doesn't have an EFI partition whereas "Shared Support" does. The EFI partition on Shared Support appears to be a read only file system so I can't make an EFI folder for it. How can I resolve this? I can't seem to change the permissions of Shared support...

Re-download the installer and use the correct parameters to erase the drive.

Read here:

GUIDE - How to Boot macOS Installer on Desktops and Laptops using OpenCore [UEFI/Legacy] - OpenCore Install Guide

How to Boot macOS Installer on Desktops and Laptops using OpenCore [UEFI/Legacy] - OpenCore Install Guide Booting the OS X/macOS installers on a non-Apple computer can be challenging for new users. This guide is intended for those who wish to use OpenCore as a Bootloader and it covers a...

elitemacx86.com

CandyManOfficial · May 27, 2023

EliteMacx86 said:
Re-download the installer and use the correct parameters to erase the drive.

Read here:

GUIDE - How to Boot macOS Installer on Desktops and Laptops using OpenCore [UEFI/Legacy] - OpenCore Install Guide

How to Boot macOS Installer on Desktops and Laptops using OpenCore [UEFI/Legacy] - OpenCore Install Guide Booting the OS X/macOS installers on a non-Apple computer can be challenging for new users. This guide is intended for those who wish to use OpenCore as a Bootloader and it covers a...

elitemacx86.com

Same problem unfortunately.

EliteMacx86 · May 27, 2023

CandyManOfficial said:
Same problem unfortunately.

Which method are you using to download the installer and create the Bootable USB?

CandyManOfficial · May 27, 2023

EliteMacx86 said:
Which method are you using to download the installer and create the Bootable USB?

From the app store on my macbook. I then used the createinstallmedia command from the guide. To be honest, I think this problem may just be something with my flash drive itself. I don't know why it won't create an EFI partition.

EliteMacx86 · May 27, 2023

CandyManOfficial said:
From the app store on my macbook. I then used the createinstallmedia command from the guide. To be honest, I think this problem may just be something with my flash drive itself. I don't know why it won't create an EFI partition.

Could be possible. Try with another USB Flash Drive and another USB Port. Make sure to verify the installer size.

The parameters you should use:

USB
HFS+
GUID Partition Map

Unless you select GUID Partition Map as a Scheme, it will NOT create a hidden ESP.

BrubruX23 · 2025-12-30T17:00:27+0000

Basically it's the state of your USB drive that has to be formatted as GPT and FAT File System. From that specific drive state, you will be able to create the Media. The Installation tool will shrink to an EFI partition and build an HFS+ install media aside from this partition.

The USB must be formatted in GPT FAT32 in an OSX Terminal, type:

Bash:

diskutil eraseDisk Fat32 UNTITLED GPT /dev/disk4

if USB is disk4 (look into the DiskUtil list)

Note: If your in a PC DOS/LINUX environment, format the usb disk, and it lead you to the same result.

You can then try the createinstallmedia function:

Code:

sudo /Volumes/Install\ macOS\ Big\ Sur/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/UNTITLED

Search

Creating an installer on MacOS doesn't create EFI partition

CandyManOfficial

New member

EliteMacx86

Administrator

GUIDE - How to Boot macOS Installer on Desktops and Laptops using OpenCore [UEFI/Legacy] - OpenCore Install Guide

CandyManOfficial

New member

GUIDE - How to Boot macOS Installer on Desktops and Laptops using OpenCore [UEFI/Legacy] - OpenCore Install Guide

EliteMacx86

Administrator

CandyManOfficial

New member

EliteMacx86

Administrator

BrubruX23

New member

Similar threads

Featured content

Trending content

Latest posts

Forum statistics

Share this page