How to install macOS Monterey in VirtualBox on MAC?

What is the correct process of installation of macOS Monterey on VirtualBox on MAC?

Before starting, we can highlight several advantages of the installation of macOS on virtual machine on MAC: - 
1- Can be used for testing of any new versions of macOS instead of direct installation on the main machine.
2- Can be used for installation of unsupported macOS versions as you van adjust virtual setting in the virtual machine to help the unsupported versions to work.
3- Can be used for  testing of compatibility of certain applications on multiple macOS.
4- Give you the chance to install other macOS in isolated environment. for example you may have macOS Monterey in the main machine and on the same time you can install macOS Big Sur, Mojave, Sierra, .... on the virtual machine.
5- the process is totally free as virtualbox is a free software and macOS can be downloaded from App Store freely. 

You can watch the whole process of installation of macOS Monterey on VirtualBox on MAC in this video [12 minutes]: -

How to install macOS Monterey in VirtualBox on Mac?

You can follow these six steps: -
Step 1: Download virtualbox and the suitable extensions on macOS.
Step 2: Download macOS Monterey installer on macOS.
Step 3: Install VirtualBox on macOS and fix errors.
Step 4: Convert macOS installer.app to ISO image (macOS Montery installer.iso).
Step 5: Adjust the settings of VirtualBox to be suitable for macOS.
Step 6: Format the virtual hard drive and Install macOS Monterey into VirtualBox.
 

Step 1: How to download VirtualBox and the suitable extensions on macOS ?

- VirtualBox is a free software so the latest version can be downloaded from its official website using the following link: -
https://www.virtualbox.org/wiki/Downloads            Just select the "OS X hosts"

- You have to download "VirtualBox Extension Pack" which provide Support for USB 2.0 and USB 3.0 devices, VirtualBox RDP, disk encryption, NVMe and PXE boot for Intel cards, from the following link: -
https://download.virtualbox.org/virtualbox/6.1.34/Oracle_VM_VirtualBox_Extension_Pack-6.1.34.vbox-extpack
​

Step 2: How to download macOS Monterey installer on macOS ?

- The official macOS Monterey can be downloaded from:- 
a) macOS Monterey can be downloaded from App Store using this link.
b) also, you can download the official new and old macOS using this link.

- The App Store method involve: -
1- Open the App store and write in the search bar: macOS Monterey.
2- The select macOS Monterey from the search result and press "get" button.
3- Wait until the download completed and never press the install button.
4- Go to the "applications folder" and search of a file named "install macOS Monterey.app"
5- Move the file named "install macOS Monterey.app" to the desktop.
​

Step 3: How to install VirtualBox on macOS and fix errors ?

1- Open the DMG installer and double click "VirtualBox.pkg".
2- Accept all the messages and follow the steps until you get a message of successful installation.
3- You may face a problem that prevent from running macOS virtual machine. The problem reports a message "Kernel driver not installed (rc=-1908)". this problem can be fixed following the steps described in this video.
​

Step 4: How to convert macOS installer.app to macOS Montery installer.iso ?

- You have to follow these steps carefully and copy the terminal commands as it is.
​- The process of converting "install macOS Monterey.app" to a bootable "install macOS Monterey.iso" is very important as VirtualBox can run only run macOS installation from "iso" images only.

- Follow these steps for converting .app to .iso : -
1- you must ensure that you have enough disk space for running the full process of installing macOS Monterey on virtualBox. at least 55 Gigabytes.
2- Open terminal. using spotlight search type "terminal" and press enter. then start typing the following terminal commands:
3- Command 1:
create a dmg container on the desktop of a size (15 BG) named "Monterey.dmg": -
hdiutil create -o ~/Desktop/Monterey -size 15000m -volname Monterey -layout SPUD -fs HFS+J
4- Command 2:
mount the Monterey.dmg container into your device: -
hdiutil attach ~/Desktop/Monterey.dmg -noverify -mountpoint /Volumes/Monterey
5- Command 3:
Create a bootable macOS Monterey installer into the created dmg container  (N.B. You must have install macOS Monterey.app into your desktop as described before in step 2): - 
sudo ~/Desktop/Install\ macOS\ Monterey.app/Contents/Resources/createinstallmedia --volume /Volumes/Monterey --nointeraction
6- Command 4:
detach the created bootable dmg container: -
hdiutil detach /Volumes/Install\ macOS\ Monterey
7- Command 5:
Convert dmg to cdr container: -
hdiutil convert ~/Desktop/Monterey.dmg -format UDTO -o ~/Desktop/Monterey.cdr
8- Command 6:
​convert cdr to the bootable iso image: - 
mv ~/Desktop/Monterey.cdr ~/Desktop/Monterey.iso

NOW, you have created  a bootable Monterey.iso image that can be used with VirtualBox virtual machines as shown in the following picture (1): - 

Step 5: How to adjust the settings of VirtualBox to be suitable for macOS.

1- Open VirtualBox, in the main interface press new, then name the virtual machine macOS Monterey. select its version properties as "macOS 10.13 High Sierra" - Picture (2).
​2- Adjust the memory size to be around 5000 MB. - Picture (3).
3- Select the hard drive file type to be "VHD (Virtual hard Disk)" and adjust its size to be at least 35 MB. Then press create. - Picture (4).
4- Now you have created the virtual machine but it needs further adjustments. press settings and navigate to the "system" icon. then under processor tab, adjust the number of processors to be 2. - Picture (5).
​5- Under the "Display" icon, adjust the memory size to be 128 MB. - Picture (6).
​6- Under the "Storage" icon, select "Monterey.iso" to be mounted as the optical drive. - Picture (7).
7- Now the virtual machine is ready for the installation of macOS Monterey and the picture shows the whole settings. - Picture (8).

Picture (2): Open VirtualBox, in the main interface press new, then name the virtual machine macOS Monterey. select its version properties as "macOS 10.13 High Sierra"

Picture (3): Adjust the memory size to be around 5000 MB.

Picture (4): Select the hard drive file type to be "VHD (Virtual hard Disk)" and adjust its size to be at least 35 MB.

Picture (5): Now you have created the virtual machine but it needs further adjustments. press settings and navigate to the system icon. then under processor tab, adjust the number of processors to be 2.

Picture (6): Under the "Display" icon, adjust the memory size to be 128 MB.

Picture (7): Under the "Storage" icon, select "Monterey.iso" to be mounted as the optical drive.

Picture (8): Now the virtual machine is ready for the installation of macOS Monterey and the picture shows the whole settings.

Step 6: How to install macOS Monterey into the prepared VirtualBox ?

1- just open the prepared macOS Monterey virtual machine that was prepared from the last step and press "start"
2- select your suitable language and you will be taken to the recovery mode screen.

The recovery mode screen.

3- Open "Disk Utility" and format the virtual hard drive (35 GB) to be suitable for macOS Monterey and wait for the erase process to complete.

format the virtual hard drive (35 GB) to be suitable for macOS Monterey

4- Close disk utility and select "install macOS Monterey" from the main screen.
5- Proceed with the installation as shown in the video.