Network bonding refers to the combination of network interfaces on one host for redundancy and/or increased throughput. Redundancy is the key factor: we want to protect our virtualized environment from loss of service due to failure of a single physical link. This network bonding is the same as the Linux network bonding or Oracle Solaris data link aggregation. Using network bonding in Oracle VM may require some switch configuration.
In Oracle VM, there are three modes of network bonding:
Active Backup: there is one NIC active while another NIC is asleep. If the active NIC goes down, another NIC becomes active. While this mode does not increase throughput, it provides redundancy in case of failure. Active Backup is only supported in x86 environments.
Dynamic Link Aggregation: aggregated NICs act as one NIC which results in a higher throughput, but also provides failover in the case that a NIC fails. Dynamic Link Aggregation requires a switch that supports IEEE 802.3ad.
Adaptive Load Balancing: the network traffic is equally balanced over the NICs of the machine and failover is also supported to provide redundancy. Unlike Dynamic Link Aggregation, Adaptive Load Balancing does not require any particular switch configuration. Adaptive Load Balancing is only supported in x86 environments.
Only Dynamic Link Aggregation is currently supported for SPARC servers.
During installation of Oracle VM Server, the network interface (selected when prompted for the management port) is configured as a bonded interface. The bond is created with only one interface. This is done because the reconfiguration of the management interface on the Oracle VM Servers is not supported. You can add a second interface to the already existing bond device without affecting the configuration of the original interface. This is illustrated in Figure 5.2, “Network bonding”, where a second network interface is added to bond0, the network bond created during installation. By default, the bond mode is set to Active Backup for the management network.
Figure 5.2, “Network bonding” also illustrates the configuration of a second bonded interface, bond1, which can be used for other network usage, such as the virtual machine function.