DLPAR tuning tools
There are several tools that can be used to monitor and support DLPAR.
With DLPAR, the number
of online processors can change dynamically. In order to track the difference
between the number of online processors and the maximum number of processors
possible in the system, you can use the following parameters:
- _system_configuration.ncpus
- Queries the number of online processors
- _system_configuration.max_ncpus
- Provides the maximum number of processors possible in the system
AIX® supports trace hook 38F to enable the trace facility to capture the addition and removal of processors and memory.
Performance monitoring tools such as curt, splat, filemon, netpmon, tprof, and pprof are not designed to handle DR activity. They rely on static processor or memory quantities. In some cases, a DR operation performed while the tool is running might not have any side effect, for example with the tprof and pprof tools. However, the DR operation could result in undefined behavior or misleading results with other tools like the curt tool, for example.
There are tools that support DR operations. These tools are designed to
recognize configuration changes and adjust their reporting accordingly. Tools
that provide DLPAR support
are the following:
- topas
- There are no changes to the interface, nor to the interpretation of the output. When you perform a DR operation, the topas tool will recognize the addition or removal of the resource and will report the appropriate statistics based on the new set of the resources.
- sar, vmstat, and iostat
- There are no changes to the interfaces, nor to the interpretation of the output of these commands. When you perform a DR operation, a message is sent to you, informing you of a configuration change. The tools then begin reporting the appropriate statistics based on the new set of resources.
- rmss
- There is no change to the invocation of this command and it continues to work as expected if a DR operation occurs while the rmss tool is running.