Pre-installation Steps

Setup recoveryOS utility

The recoveryOS utility is from my project on GitHub. The programs are included in the OC4VM tools folder for your operating system.

qemu-img

Note

Do make sure the qemu-img utility is installed on your system so the correct disk format can be created from the raw download.

You will need to have qemu-img utility, from QEMU, on the path.

• Linux - These can be installed from Linux repos, for example Debian based distros

  sudo apt install -y qemu-utils

• macOS - use brew package manager to install on macOS

  brew install qemu

• Windows - use Chocolatey or Scoop to install on Windows

  choco/scoop install qemu

Run recoveryOS and create a recovery VMDK

Navigate to OC4VM tools folder and then switch to the folder for your host operating system.

• Linux - tools/linux/
• macOS - tools/macos/
• Windows - tools/windows/

Open a terminal or shell and then run the recoveryOS program in that folder.

 ./recoveryOS 

From the menu select 6 for Sequoia and press enter to start the download. When the download has complete another menu is displayed to select output formats, and you should select 1 for VMDK and press enter.

This is the output you should see when running the program.

OC4VM recoveryOS Image Maker
============================
Version 1.0.0-e04f399
(c) David Parsons 2022-25

Create a recoveryOS virtual image
1. Catalina
2. Big Sur
3. Monterey
4. Ventura
5. Sonoma
6. Sequoia
7. Tahoe

0. Exit
Input menu number: 6
Downloading DMG...

Downloading 093-10615...
Saving http://oscdn.apple.com/content/downloads/52/42/093-10615/f1wx7fb81oy1x1l3d5kjfce2iurbhw9qbk/RecoveryImage/BaseSystem.chunklist to sequoia.chunklist...
0.0 MB downloaded...                                                          
Download complete!
Saving http://oscdn.apple.com/content/downloads/52/42/093-10615/f1wx7fb81oy1x1l3d5kjfce2iurbhw9qbk/RecoveryImage/BaseSystem.dmg to sequoia.dmg...
847.4/847.4 MB |==========================| 100.0% downloaded                 
Download complete!
Verifying image with chunklist...
Chunk 85 (7811435 bytes)                                                      
Image verification complete!

Convert the recoveryOS virtual image
1. VMware VMDK
2. QEMU QCOW2
3. Microsoft VHDX
4. Raw image
5. All

0. Exit
Input menu number: 1
Converting to vmdk:
    (100.00/100%)
Created vmdk disk: sequoia.vmdk

Done! Your recoveryOS image is ready.

List the folder contents and you should see these 3 files.

sequoia.chunklist sequoia.dmg sequoia.vmdk

You can delete the chunklist and dmg files if needed.

Copy the VMware template

Open the OC4VM folder and navigate to the vmware folder. Copy either the AMD or Intel folder to a new location. The new folder can be renamed if required.

Open VM

Now we are going to setup the new VM to use the downloaded recovery image.

Change CPU count

I recommend changing the core count from the defaults in the template. Whilst the defaults work it would be better to increase them to privide more processing power.

Always use multiples of 2 if possible as there are issues with odd core counts. So in this example we see the defailts as 1 CPU & 2 cores.

This has been doubled be increasing the core count.

Important

During installation keep cores and memory values close to the defaults. It is better to get macOS installed take a snapshot and then experiment with larger values. You can always rollback the snapshot if something goes wrong.

Add RecoveryOS VMDK to the VM

Next we will add the sequioa.vmdk created earlier to the VM.

Click on the "Add" button in the "Virtual Machine Settings" dialog and select "Hard Disk"

Use "SATA" as the disk type.

And select "Use an existing virtual disk".

Browse and select the sequoia.vmdk file and press "Finish"

You may be prompted to convert the file and you can select either option but do not press "Cancel".

You should now see the sequoia.vmdk file added to guest settings.

Finally save the VM and got to Installing macOS.