IBM has a vast heritage in virtualisation. They were doing it back in the 60s to achieve better hardware utilisation out of the expensive mainframe. By drawing on that experience and applying it to the IBM Power Systems, the resulting PowerVM brings granular, logical partitioning up-to-date. But, by installing the optional Virtual I/O Server (VIOS) on top of the Hypervisor, a great deal of flexibility and functionality can be unlocked. Some of these benefits are not restricted to just the operational aspects of the Power System.
The VIOS is a bespoke AIX appliance designed to virtualise disk and network access. The VIOS acts as a conduit for the client AIX logical partitions to gain access to storage either via virtual SCSI connections or with N-Port Virtualisation (NPIV) which acts more like traditional SAN connected fibre channel storage. This allows a storage administrator to control the allocation of storage to the clients, rather than the AIX administrator. The VIOS also allows access to the network using a virtual network approach that extends the physical network/s into the Power System. There are several immediate benefits to this approach:
- It reduces the I/O adapters required as each client no longer needs physical storage adapters and NICs.
- It reduces the physical setup time for the server. There are fewer adapters to cable up.
- It can reduce the need to physically add adapters to the system. The clients simply require virtual adapters from the hypervisor that pass through the VIOS physical cards.
- It improves the utilisation of the adapters, especially high performance fibre channel cards and network adapters that can be driven better through consolidation.
Installing a pair of VIOS in a redundant configuration will improve the resilience and management by allowing a single VIOS to be shut down for maintenance or handle an unplanned outage without a loss of service.
Once a configuration of this type has been installed, it then provides an ideal platform for rapid virtual machine deployment. Pushing images from a network install manager (NIM) server, coupled with a standardised virtual machine configuration that no longer requires any cabling or networking switch setup, that can often slow down a traditional machine deployment, which means more time for more important tasks.
IBM’s Virtual I/O Server can have a real impact on the day-to-day activities of an AIX systems administrator. Working in conjunction with the PowerVM hypervisor and capabilities such as Shared Processors, Dynamic Logical Partitioning (DLPAR) and Active Memory Sharing (AMS) the VIOS can greatly improve the utilisation of the Power hardware.
For any server requirements please do not hesitate to contact Celerity Limited
Steve Laidler - Celerity Technical Consultant - Celerity Limited