Unable to Snapshot Instance: "Image <path>/disk is unacceptable: Unable to convert image to qcow2"

Problem

• Unable to snapshot an instance (in any power state).

• The following logs are present in /var/log/pf9/ostackhost.log file on the hypervisor.

Environment

• Platform9 Managed OpenStack - All Versions

• Nova

• Glance

Cause

The backing file for the instance is missing, which can occur if an instance becomes un-defined in Libvirt – for example, due to a partially failed migration. The root cause for the backing file missing may be different under certain circumstances.

Resolution

Option A: Copy the Backing File from Another Hypervisor

1. From a working, functional hypervisor – if an instance is scheduled with the same image as the one which is failing to snapshot, it may have a copy of the same data which you can use to copy. Check for any matching folders/files in /opt/pf9/data/instances/_base/ .

2. Copy the directory/files to the same path on the non-functional hypervisor.

3. Attempt to re-build the instance.

Option B: Migrate the Instance

1. Migrate the instance. The image should be re-downloaded from Glance to the hypervisor.

2. Snapshot the instance.