* Power5, virtualization can lead to better management of IBM servers
IBM demonstrated virtualization capabilities on its servers and storage at its recent analyst conference. Though IBM has several different virtualization capabilities in its arsenal, in this article I will focus on IBM’s micro-partitioning capabilities on its Power5 systems.
Power5 is the latest chip from IBM, which will be available on its servers from the high end to the low end.
IBM does logical partitioning (LPAR) on its systems. However, on systems using the Power4 chip, the predecessor to the Power5, a processor had to be assigned to a logical partition. So whether an application needed the services of a whole processor or not, it was assigned the whole processor. If the processor requirements of the application in an LPAR were not very demanding, that partition would have extra processor capacity that would consistently be underutilized. In addition, I/O devices had to be assigned to each LPAR.
Power5 brings the ability to assign virtual processors and subsets of virtual processors to each of the LPARs. So if an application routinely requires 20% of a processor, you can assign just 20% of a virtual processor to that LPAR. Once all of the virtual processors are assigned to the LPARs, whatever processor capacity that remains is part of a processor pool that can be used as needed.
Administrators can set up the virtual processors in each LPAR as capped, uncapped or dedicated. “Capped” means that the assigned percentage of virtual processor capacity always stays the same until the administrator changes it. “Uncapped” means that if the application in the LPAR temporarily requires more virtual processing power than it has been allocated, and excess processing capacity is available, the system can dynamically add virtual processing power to that LPAR to help with performance. “Dedicated” means that the processor power assigned to the LPAR is fixed and never shared with other LPARs. In addition, if the processors are designated as a shared resource, the dynamic load balancing between LPARs that are designated as uncapped can allocate additional processing power dynamically when needed.
The administrator also can weight each LPAR, which essentially serves to set priorities for allocating processing power. So if several applications running in separate LPARs are contending for additional processing resources, the weightings will determine which LPARs receive priority for gaining added processing power.
In addition to the micro-partitioning described above, the Power5 servers also have the ability to use virtual I/O. The virtual I/O avoids the requirement on Power4 systems to assign I/O for each LPAR – which was a potential waste of I/O resources on the Power4 systems.
One of the facets of IBM’s server strategy is to leverage its valuable mainframe technologies, such as virtualization, and to build it into the rest of its server lines, including pSeries, iSeries, xSeries and BladeCenter. The use of the Power5 chip and the virtualization capabilities in its hardware are proof that IBM is delivering on its promised strategy. This is also more evidence of hardware vendors, like IBM, building in management capabilities to differentiate from their competitors.
Servers with built-in virtualization capabilities like micro-partitioning provide users with flexible multi-way servers that can be configured to optimize the utilization of system processing resources across multi-threaded workloads. I’ve been talking about the trend of embedded management in hardware for a while. And as management technologies such as virtualization become embedded into the hardware layer, the value that the embedded management brings to its users can be significant.
