Overview

A live migration is the process of transferring running cVMs across different servers.

Figure 1 cVM live migration process

• cVMs do not support live migration in device passthrough scenarios. Additionally, SVE live migration and QEMU-side autostart are not yet supported.
• A live migration requires that the source and target servers be in the same network segment, have the same CPU configuration (model, number of cores, frequency, and sysreg flag), and use a shared storage pool to store cVM images.
• Restrictions on cVM specifications: The number of vCPUs on the cVM to be migrated is less than or equal to 32, and the memory is less than or equal to 512 GB. If the cVM has multiple vNUMA nodes, the memory of all vNUMA nodes except the last one must be 1 GB aligned.
• In this section, the server that hosts the VM to be migrated is called the source server, and the server to which the VM will be migrated is called the target server.
• To enable the cVM live migration service, you need to run mig-agent. Currently, mig-agent can be run in either of the following modes: 1. Start the cVM migcvm on the source and target servers, and run migcvm-agent on the migcvm. migcvm-agent implements remote attestation and memory verification, and assists in live migration of service cVMs. 2. Directly start mig-agent on the source and target servers. mig-agent implements memory verification and assists in live migration of service cVMs.
• The migcvm cVM is controlled by a trusted third party and is used to run the migcvm-agent to perform remote attestation and key exchange between the source and target ends.