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Introduction to vNIC FAQs

By Chuck Graham posted Fri June 19, 2020 09:08 AM

vNIC (Virtual Network Interface Controller) is a new PowerVM virtual networking technology that delivers enterprise capabilities and simplifies network management. It is a high performance, efficient technology that when combined with SR-IOV NIC provides bandwidth control Quality of Service (QoS) capabilities at the virtual NIC level. vNIC significantly reduces virtualization overhead resulting in lower latencies and less server resources (CPU, memory) required for network virtualization.

Figure 1 illustrates how control information and data flows within a POWER8 system for a client vNIC adapter.  The client partition’s vNIC adapter control flow interface to the Virtual I/O Server (VIOS) is a virtualized interface to hide characteristics of the physical I/O adapter from the client vNIC adapter.  Virtualizing the vNIC adapter interface allows the client partition to be a candidate for Live Partition Mobility (LPM). 

To provide an efficient and managed transfer of data between partition memory and the I/O adapter, each client vNIC adapter is associated with a VIOS SR-IOV logical port in a one-to-one relationship.   In this configuration the SR-IOV adapter hardware manages the routing of data between the adapter and partitions without additional overhead of the hypervisor or VIOS.  This configuration also allows for bandwidth control QoS characteristics for the client vNIC adapter by mapping each client vNIC adapter to its own adapter virtual function (VF).  

PowerVM introduced vNIC in 2015 on POWER8 systems. Given the strong customer interest in this technology, we compiled answers to frequently asked questions that are covered in this post.  These and additional FAQs related to vNIC and be found at PowerVM vNIC Frequently Asked Questions.  We will keep these updated & expand on them based on future offerings and customer questions.

For additional information on PowerVM vNIC support see vNIC - Introducing New PowerVM Virtual Networking Technology.
vPowerVM vNIC backed SRIOVNIC FAQs
What are the requirements for vNIC?
  • Systems
    • IBM Power System E870 (9119-MME), IBM Power System E880 (9119-MHE)
    • IBM Power System S824 (8286-42A), IBM Power System S814 (8286-41A)
    • IBM Power System S822 (8284-22A), IBM Power System S824L (8247-42L)
    • IBM Power System S822L (8247-22L), IBM Power System S812L (8247-21L)
    • Note: IBM Power System E850 (8408-E8E) to follow at a future date
  • vNIC is also supported when the SR-IOV enabled adapter is in the PCIe Gen3 I/O expansion drawer(2 SR-IOV slots per Fan-out Module )
  • PowerVM 2.2.4
    • VIOS Version 2.2.4
    • System Firmware Release 840
    • HMC Release 8 Version 8.4.0
  • Operating Systems
    • AIX 7.1 TL4 or AIX 7.2
    • IBM i 7.1 TR10 or IBM i 7.2 TR3
    • Note: Linux support to follow at a future date.
Is a partition with vNIC virtual adapters a candidate for LPM and remote restart?

How do the PowerVM network virtualization technologies for Ethernet adapters compare?
PowerVM Ehternet Adapters

  1. SR-IOV can optionally be combined with VIOS and virtual Ethernet to use higher-level virtualization functions like Live Partition Mobility (LPM); however, client partition will not receive the performance or QoS benefit.
  2. Some limitations apply.  See FAQ on link aggregation
  3. Generally better performance and requires fewer system resources when compared to SEA/virtual Ethernet
Which I/O adapters support vNIC?
All SR-IOV adapters available on POWER8 system can be the backing device for a client vNIC adapter.  The adapter must be in SR-IOV shared mode prior to creating a client vNIC virtual adapter.
PowerVM vNIC Capable Adapters

How many vNIC clients are supported per SR-IOV adapter?
PowerVM vNIC Clients per Adapter
Refer to PowerVM vNIC Frequently Asked Questions for a complete set of vNIC related frequently asked questions.

Contacting the PowerVM Team
Have questions for the PowerVM team or want to learn more?  Follow our discussion group on LinkedIn IBM PowerVM or IBM Community Discussions