HydraVM: Low-Cost, Transparent High Availability for Virtual Machines

Existing approaches to providing high availability (HA) for virtualized environments require a backup VM for every primary running VM. These approaches are expensive in memory because the backup VM requires the same amount of memory as the primary, even though it is normally passive. In this paper, we propose a storage-based, memory-efficient HA solution for VMs, called HydraVM, that eliminates the passive memory reservations for backups. HydraVM maintains a complete, recent image of each protected VM in shared storage using an incremental checkpointing technique. Upon failure of a primary VM, a backup can be promptly restored on any server with available memory. Our evaluation results have shown that HydraVM provides protection for VMs at a low overhead, and can restore a failed VM within 1.6 seconds without excessive use of memory resource in a virtualized environment. Keywords-Virtualization; High Availability; VM Checkpointing; VM Restore; Shared Storage; Submission Category: Regular paper Word Count: 9345 words Declaration: The material has been cleared through all authors’ affiliations.