The Continuity of Out-of-Band Remote Management across Virtual Machine Migration in Clouds

In Infrastructure-as-a-Service (IaaS) clouds, users remotely manage the systems in virtual machines (VMs) called user VMs, e.g., Through VNC. To allow users to manage their VMs even on failures inside the VMs, IaaS usually provides out-of-band remote management. This VM management is performed indirectly via a VNC server in a privileged VM called the management VM. However, it is discontinued when a user VM is migrated from a source to a destination host. This is because a VNC server in the management VM at a source host is terminated on VM migration. Even worse, pending data is lost between a VNC client and a user VM. In this paper, we propose D-MORE for continuing out-of-band remote management across VM migration. D-MORE provides a privileged and migratable VM called DomR and performs out-of-band remote management of a user VM via DomR. On VM migration, it synchronously co-migrates DomR and its target VM and transparently maintains the connections between a VNC client, DomR, and its target VM. We have implemented D-MORE in Xen and confirmed that a remote user could manage his VM via DomR even after the VM has been migrated. Our experiments showed that input data was not lost during VM migration and the overhead of D-MORE was acceptable.