Encryption of live migration data

Available since MOSK 23.2

Live migration enables the seamless movement of a running instance to another node within the cluster, ensuring uninterrupted access to the virtual workload.

In MOSK, the native TLS encryption feature is available for QEMU and libvirt, securing all data transports, including disks not on shared storage. Additionally, the libvirt daemon exclusively listens to TLS connections.

To establish a TLS environment, encompassing CA, server, and client certificates, the relevant compute nodes automatically generate these components. By default, these certificates are encrypted with a 2048-bit RSA private key and are valid for 3650 days.

You can easily enable live migration over TLS by configuring the features:nova:libvirt:tls parameter in the OpenStackDeployment custom resource. For reference, see Live migration.


Instances started before enabling secure live migration will not support live migration.

The issue arises due to the SSL certificates for live migration with QEMU native TLS being generated during the service update. Thus, these certificates do not exist in the libvirt container when existing instances were started. Consequently, QEMU processes of those instances lack the required SSL certificate information, leading to migration failures with an internal error:

internal error: unable to execute QEMU command ‘object-add’: Unable to access credentials /etc/pki/qemu/ca-cert.pem: No such file or directory

As a workaround, stop and then start the instances that failed to live migrate. This process will create new QEMU processes within the libvirt container, ensuring the availability of TLS certificate details.