Supported offline handoff boundary for a macOS VM disk image and auxiliary storage

We need a supported checkpoint after macOS installation before an independent process verifies and later boots the VM. We distinguish installer success, actual VM stopped state, application queue drain, reference release, and file synchronization.

  1. After installation completes without error and the same VM is stopped, can Virtualization still submit writes to the disk image or auxiliary storage? What documented barrier ends them?
  2. Does releasing all application references and autorelease scopes and draining the VM queue end storage writes by all SDK objects, internal tasks, and services?
  3. After the producer process exits and is waited for, can services, transferred handles, or pending framework buffers still modify either file?
  4. Is there a supported joint durability/consistency boundary for disk and auxiliary storage beyond the disk image Full guest-flush guarantee?
  5. What handoff sequence and platform versions does Apple support for sequential installation, offline verification, and boot processes?

We are asking for the contract, not proposing forced stop, delayed hashing, or an undocumented recovery procedure.

Answered by DTS Engineer in 911934022

I recommend that you have a read of this thread, where we’ve been discussing this issue and various related ones.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

I recommend that you have a read of this thread, where we’ve been discussing this issue and various related ones.

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

Thank you. I read the linked disk-image guidance for macOS 27 and later. Our remaining resource is VZMacAuxiliaryStorage, rather than VZEFIVariableStore.

For the same VM after a normal guest shutdown and guestDidStop(_:), with the application submitting no further mutable work, does the supported boundary also cover all outstanding framework or helper-process writes to the Mac auxiliary-storage file, so another process may read and later use the disk image and auxiliary storage as a pair?

Separately, what synchronization sequence, if any, establishes a durable and mutually consistent disk-plus-auxiliary-storage checkpoint, and what runtime versions does that guidance cover?

We are not proposing a forced stop as a clean-shutdown substitute.

Didn’t I already answer that here?

Share and Enjoy
—
Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"