Managing virtual Network Interface Controllers
A virtual Network Interface Controller (vNIC) is a type of virtual Ethernet adapter that is configured on client partitions of Power Systems™ servers. Each vNIC is backed by an SR-IOV logical port that is available in a Virtual I/O Server (VIOS) partition. This type of vNIC is also called dedicated vNIC, as the backing SR-IOV logical port serves the vNIC exclusively. The key advantage of placing the SR-IOV logical port in the VIOS is that it makes the client LPAR eligible for Live Partition Mobility (LPM). Although the backing device resides remotely, through a mature PowerVM® technology that is known as Logical Redirected DMA (LRDMA), the vNIC can map its transmit and receive buffers to the remote SR-IOV logical port when a one-to-one relationship exists between the vNIC and the backing logical port. After the buffers are mapped, the SR-IOV logical port directly fetches/stores packet data from/to the memory of the client partition. The LRDMA technology eliminates two data copies incurred in the traditional virtual Ethernet backed by Shared Ethernet Adapter, thus lowering CPU and memory consumption on the VIOS. Furthermore, because of the one-to-one relationship, the resources that are provisioned for the SR-IOV logical port are owned by the vNIC. As a result, the vNIC inherits all the capabilities that the SR-IOV adapter offers such as the QoS minimum-bandwidth assurance and the ability of setting PVID, VLAN ACL, and MAC ACL.
- System firmware level FW840 and HMC 840
- VIOS 2.2.4.0
- vNIC driver support from AIX® and IBM® i systems
Dedicated vNICs backed up by SR-IOV logical ports
For dedicated vNICs, SR-IOV logical ports are the only ones that can be used as backing devices. To create a vNIC, you need to specify the hosting VIOS, in addition to the backing SR-IOV adapter and the physical port from which the logical port is to be allocated. You can also specify the VLAN settings and the MAC settings. For more information, see Adding virtual NICs.The VLAN settings and MAC settings are applied to both the vNIC and the SR-IOV logical ports. Default settings are applied if you do not specify the required parameters. When you add a vNIC in the client LPAR, the backing devices are provisioned and configured automatically by the HMC (based on your specification or defaults). Similar automation is performed for vNIC removal. This setup implies that you need to deal with only the client vNIC adapter and not be concerned with the management of backing devices, in normal cases.
- HMC supports the vNIC configuration in GUI, command line, and REST APIs.
- Most of the HMC GUI support for vNIC (vNIC add, delete, or edit) is available in the enhanced HMC mode only (not in the classic mode).
- HMC automated management of the backing devices requires RMC connection to the hosting VIOS.
LPM consideration for vNIC
During Live Partition Mobility (LPM) or Remote Restart operations, HMC handles the creation of the vNIC server and backing devices on the target system and cleanup of devices on the source system, when LPM completes successfully. HMC has built-in capability to provide auto-mapping of backing devices and hosting Virtual I/O Servers between the source and target servers. The SR-IOV port label, the available capacity and the VF count, and the adapter and VIOS redundancy are some of the key factors used by the HMC for auto-mapping. Optionally, you can also specify your own mapping settings.
