VM Clone

Duplicate an existing workspace instantly using APFS copy-on-write. The clone gets a fresh identity but shares disk blocks with the original, so it uses near-zero additional disk space.

Overview

Cloning uses the macOS clonefile() system call to create APFS copy-on-write copies of the VM's disk image, hardware model, and auxiliary storage. Only blocks that are subsequently modified in either the original or the clone consume additional disk space.

What Gets Cloned vs. Regenerated

ItemBehavior
Disk imageAPFS COW clone (shared blocks)
Hardware modelAPFS COW clone
Auxiliary storageAPFS COW clone
Machine identifierRegenerated (new unique ID)
MAC addressRegenerated (new random address)
config.jsonNew file with same hardware settings, cleared per-instance state
Shared foldersNot carried over (cleared)
Port forwardsNot carried over (cleared)
SnapshotsNot carried over (empty directory)
Suspend stateNot carried over (clone boots fresh)

GUI Usage

Right-click any stopped VM in the main window and select Clone. You'll be prompted to enter a name for the new workspace. The clone appears in the VM list immediately.

Disk Efficiency

Because APFS copy-on-write shares underlying data blocks, cloning a 64 GiB VM takes only milliseconds and uses almost no additional disk space initially. As you modify files inside the original or clone, only the changed blocks diverge and consume real storage.

This makes cloning ideal for creating throwaway test environments, templating workflows, or spinning up multiple variations of a base workspace.

Stop the VM first

The source VM must be stopped before cloning. Cloning a running VM would produce an inconsistent disk image. The CLI and GUI both enforce this requirement.

APFS Required

Copy-on-write cloning requires an APFS volume. If your VMs are stored on a non-APFS volume (e.g., external HFS+ drive), the clone will fail. Move your VMs to an APFS volume first.