Planning Shared Ethernet Adapter mapping

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If you plan to use Shared Ethernet Adapters for your virtual machine networking, the Shared Ethernet Adapters must be created outside of PowerVC. The configuration of each host's Shared Ethernet Adapters determines how networks treat each host.

When you create a network in PowerVC, a Shared Ethernet Adapter is automatically chosen from each registered host. The Shared Ethernet Adapter is chosen based on the VLAN that you specified when you defined the network. You can always change the Shared Ethernet Adapter to which a network maps or remove the mapping altogether. However, consider the automatic assignment when you set up your networks if you do not want to change many settings later.

For each host, you can change the Shared Ethernet Adapter to which the network maps. You can also opt to not map the network to any of the host's Shared Ethernet Adapters. If you want virtual machines that use a network to not reside on a particular host, do not assign to the network any Shared Ethernet Adapters for that host.

How the Shared Ethernet Adapter is chosen

The Shared Ethernet Adapter is chosen based on the VLAN that you specified when you defined the network. The Shared Ethernet Adapter that is chosen as the default is the one with the same network VLAN as the new network. If no such Shared Ethernet Adapter exists, the adapter with the lowest primary VLAN ID (PVID) that is in an available state is chosen instead.

Notes:
  • If there are no usable Shared Ethernet Adapters on any host for a specific VLAN ID, you are directed to choose a different VLAN ID.
  • If a Shared Ethernet Adapter is set to Do Not Use, you can select it. However, you cannot use it in a deploy until it is not set to Do Not Use.
  • If the status for the Shared Ethernet Adapter is Unavailable, the RMC connection might be down. The connection must be fixed before you can select this adapter.

Certain configurations might assure the assignment of a particular Shared Ethernet Adapter to a network. For example, assume that you create a new network in PowerVC and choose the PVID of the Shared Ethernet Adapter or one of the additional VLANs of the primary virtual Ethernet adapter as the VLAN. In this case, the chosen Shared Ethernet Adapter must back the network; no other options are made available.

Changing the Shared Ethernet Adapter after initial configuration

Note these considerations if you change the Shared Ethernet Adapters after initial configuration:
Notes:
  • If you create a network, deploy virtual machines to use it, and then change the Shared Ethernet Adapter to which that network is mapped, your workloads are impacted. At a minimum, the network experiences a short outage while the reconfiguration takes place.
  • If you modify a network to use a different Shared Ethernet Adapter and that existing VLAN is already deployed by other networks, those other networks also move to the new adapter. To split a single VLAN across multiple Shared Ethernet Adapters, you must have separate virtual switches assigned to each of those Shared Ethernet Adapters.

Multiple servers and switches

In PowerVC, a host can have multiple dual VIOS pairs. A dual VIOS setup promotes redundancy, accessibility, and serviceability. It can enhance virtual I/O client partition performance and lets you easily expand hardware or add new functions. It also offers load balancing capabilities for Multipath I/O (MPIO) and multiple shared Ethernet adapter configurations.

Notes:
  • If you create a network, deploy virtual machines to use it, and then change the Shared Ethernet Adapter to which that network is mapped, your workloads are impacted. At a minimum, the network experiences a short outage while the reconfiguration takes place.
  • If you modify a network to use a different Shared Ethernet Adapter and that existing VLAN is already deployed by other networks, those other networks also move to the new adapter.
  • If you want to modify multiple networks to use a different Shared Ethernet Adapter on the same host and the VLAN is already configured on the host, it is recommended to edit network each at a time and have at least 5 minutes time gap for PowerVC and the host to sync with the changes.