Synology SA3400 Virtual Machine Manager s White Paper - Page 21

Synology High Availability vs. VMM High Availability Synology High Availability Empty drive slots Used drive slots Heartbeat connection Reserved Synology VMM High Availability VM 1 vCPU (High Availability) VM 1 vStorage Reserved for VM 1 VM 1 memory (High Availability) Reserved for VM 1 Storage vStorage Memory CPU vCPU Switch Figure 6: Synology High Availability and VMM High Availability require different hardware setups. While Synology High Availability relies on an identical passive server and physical heartbeat connection, VMM High Availability only reserves specific system resources, uses a regular LAN connection, and can work with different models or differently configured Synology NAS. All VMM High Availability nodes are connected over a virtual cluster network that can share the same network with other VLANs. Nodes do not need to be dedicated to one role. However, designated failover hosts need to have similar capabilities to the original host and the resources of each highly available VM will be permanently reserved on the failover target. Network connectivity must be fast, stable, and redundant, preferably using all available LAN interfaces and configuring network bonding using Link Aggregation. For instance, four LAN ports can be joined into two bonds and connected to two network switches. Lean VMM High Availability Setup With Protection HA VM 1 HA Backup Backup VM 2 of VM 3 of VM 4 HA VM 3 HA Backup Backup VM 4 of VM 1 of VM 2 VM 3 VM 4 VM 1 VM 2 VM 1 VM 2 VM 3 VM 4 vCPU vStorage Snapshot Replication Figure 7: A full VMM High Availability cluster with a replication plan can be created with three Synology NAS. In this example, two devices both host two virtual machines and serve as failover destinations for two more VMs. Data from the single VM storage node are replicated to the two computing nodes, providing extra redundancy. 19 Configuration Guide