Synology SA3400 Virtual Machine Manager s White Paper - Page 20

• Cluster heartbeat • Cluster metadata • VM to iSCSI storage • VM live migration Cluster Network Communications • Storage live migration • Image transmission • VM remote replication e. Cluster network communications Replicating, backing up, and migrating VMs and their disks between hosts increases data traffic. Network cards of 10GbE or above are recommended if such operations are performed often. Fast connectivity for the cluster network reduces I/O latency. If your VMs are expected to require larger bandwidth, we maintain a complete list of compatible and available 10GbE, 25GbE, and 40GbE network cards on our website. f. High-availability clusters VMM High Availability clusters require more resources than normal virtualization clusters, but do not demand the dedicated setup necessary for a Synology High Availability (SHA) cluster. They require more Synology NAS nodes, but allow for more flexible network configurations and device use. VMM High Availability vs. Synology High Availability Synology High Availability VMM High Availability Synology NAS x 2 Synology NAS x 3 Dedicated passive server Failover host(s) with sufficient capacity Physical heartbeat network Fast enough shared network Identical devices and configuration Identical CPUs on two nodes Incompatible DSM packages removed DSM packages not affected Major technical differences between SHA and VMM High Availability clusters include the number of nodes in a cluster, the nodes' utilization, and how nodes are connected. An SHA cluster is made up of two Synology NAS, one of which acts as a dedicated passive server and is not available for use. The two nodes are directly connected using a dedicated Ethernet cable. Their configuration is fully identical. DSM packages that are not SHAcompatible cannot be used. VMM High Availability clusters require at least three hosts and can accommodate up to seven, all of which can run their own independent DSM applications and VMs. In the minimum setup, two Synology NAS function as computing nodes, while a third serves as a shared storage node. VMs can failover between the computing nodes. 18 Configuration Guide