There are a few situations that will prevent a snapshot from loading. In all cases, you can go to the list of Sessions in the Project Manager to get the log of what went wrong. Several checks can be done, depending on the type of snapshot concerned.
If, after restoring a live snapshot, you see one of the following symptoms, it means there is an issue with restoring the live snapshot:
- Display is stuck with message
Guest has not initialized the display (yet)
- It looks like the snapshot is restored but the VM is frozen
- It looks like the snapshot is restored but the OS crashes soon after.
The most common issue is an incompatibility with the hardware options selected when the live snapshot was created, and the ones selected when restoring the live snapshot. See What you need to know and Advanced snapshot management for more details.
As a result, you should make sure the selected options match, including KVM mode and custom options. As a convenience, the live snapshots's name contains a summary of the value of common options.
- Has the VM been properly shutdown? (try
Shift + Clickon
Shutdownin windows to force a full shutdown instead of a hybrid)
- Has the parent disk snapshot been modified? If so, children snapshots become unusable!
Note that in some cases your disk snapshot may become corrupted leading to the error
Image is corrupt; cannot be opened read/write when launching QEMU. It can sometimes occur when having heavy disk I/O or killing QEMU.
To assert the level of corruption of your snapshot you can use the command
qemu-img check /path/to/your/snapshot.qcow2. A possible fix is to ask
qemu-img to fix the corruption
qemu-img check -r all /path/to/your/snapshot.qcow2.