How to make a live disk snapshot


I like to make live disk snapshots while the system is running. I do not find a documentation that tells me what I need to configure, to get the ability of a live snapshot in Open Nebula.

Right now I am having a qcow2 datastore and qcow2 images. If I click on the snapshot while the machine is running I am getting an error “Error creating new disk snapshot: Cannot perform a live DISKSNAPSHOTCREATE operation”.

What do I have to do to get the live snapshot ability. Meaning making a snapshot while the VM is running. I like to get snapshots without interrupting the running system.

Thanks for your help!

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Could you provide some more background info? OpenNebula version, datastores setup, etc.

Please provide the output from the following commands:

# <VM_ID> is the ID of the failing VM
onevm show <VM_ID> -x
onedatastore list -x
# both commands will output XML

It looks like that the VMM_MAD/TM_MAD pair is not found or not supported. But we need some more info to figure out what is going wrong.

Best Regards,
Anton Todorov

Hi Anton,

thanks for your reply. Thanks to your commands I found a mismatch between VM_MAD/TM_MAD pairs. After resolving this issue I could make live snapshot. Now it is kvm/qcow2 :wink: and not kvm/shared any longer.

But is there any documentation about what pair works with live snapshot and what pair does not? Did I missed in the documentation?

Kind regards,


Hi Danny,

I can’t find it in the docs either. This is relatively new feature so it looks like missing the corresponding docs. As storage addon contributor I am permanently tracking the code development mostly related to the storage so my “docs” are the sources where I discover such changes quickly.

The VM_MAD-TM_MAD pairs are configured in /etc/one/vmm_exec/vmmexecrc and the TM_MAD must have implemented snap_create_live.

EDIT: I’ve created issue #5038

Kind Regards,
Anton Todorov

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