Run without saving changes does not work for Apple VM

[conath]

From pyrosousa on Discord:

Does the "Run without saving changes" work for a macOS Monterrey guest on m1?

Maybe i'm misunderstanding its function, but i was testing with some text files on my desktop and all the changes i was making (pretty simple ones) were persisting.

[mikedowler]

+1 - I used "Run without saving changes" and installed some software. Rebooted the VM, and the software is still there.

[jsiegers]

+1 As well

[Javdat]

Seems to work as intended in macOS Monterrey on M1. You have to exit the "disposable mode", or re-open it. Reboot doesn't seem to exit it, hence you continue within the same "disposable mode". Closing the window and starting again will start a fresh one.

[lewurm]

There is some API in the Apple hypervisor that sounds related:
https://developer.apple.com/documentation/virtualization/vzdiskimagestoragedeviceattachment/3857729-init
https://developer.apple.com/documentation/virtualization/vzdiskimagesynchronizationmode

VZDiskImageSynchronizationMode
case none
Disables data synchronization with the permanent storage.

But UTM doesn't specify a synchronizationMode currently:

UTM/Configuration/UTMAppleConfigurationDrive.swift

Lines 100 to 105 in 917ccf9

	func vzDiskImage() throws -> VZDiskImageStorageDeviceAttachment? {
	if let imageURL = imageURL {
	return try VZDiskImageStorageDeviceAttachment(url: imageURL, readOnly: isReadOnly)
	} else {
	return nil
	}