Snapshots
A snapshot saves a VM as it is, running or not, to roll back to in seconds. It takes space only as the VM changes after it: its disk is an APFS clone that shares every block with the VM's until one of them writes.
Taking a snapshot
- In the library: Take Snapshot in the VM's … menu.
- In the VM's settings window (VM settings): Take Snapshot under Snapshots.
- On the command line:
elyravm snapshot <vm> [<name>].
A snapshot is named after the moment it is taken, such as 6 Oct 2026 at 18:12, unless the command line gives it a name. Rename next to it in the settings window gives it another: type the name, then Return (Escape leaves it as it was).
| The VM is | The snapshot holds | Taking it |
|---|---|---|
| Shut down | its disk | instant |
| Suspended | its disk and its saved state | instant |
| Running or paused | its disk and its memory | the VM is paused for a moment, saved into the snapshot, and carries on |
A VM that is starting, installing or saving can't be snapshot until it has started or stopped. A running VM whose devices can't be saved (as for suspending) can be snapshot only when shut down.
Rolling back
Roll Back next to a snapshot asks first, then puts the VM back as it was:
- its disk, and the macOS auxiliary storage or the Linux EFI variables;
- its hardware and settings as they were (its name stays as it is now);
- its memory, if the snapshot was taken while it ran.
| The VM is | After rolling back to a snapshot of a | It |
|---|---|---|
| Shut down or suspended | shut-down VM | is shut down |
| Shut down or suspended | running VM | is suspended there: ▷ carries on from that moment |
| Running | shut-down VM | is turned off, rolled back, and started |
| Running | running VM | is turned off, rolled back, and carries on from that moment, in about a second |
What changed in the VM since the snapshot is lost. The snapshot stays, to roll back to again.
Deleting
Delete next to a snapshot asks first. Deleting frees the space only the snapshot used.
Snapshots and other features
- Duplicate makes a VM without the original's snapshots.
- Moving a VM to another Mac takes its snapshots along, in its folder. A snapshot taken while running may not carry on there (a saved state fits the Mac it was saved on).
- Move to Trash takes the snapshots with the VM.