content_image/972739.jpg
While performing a takeover (for example, fallover to the next priority node), PowerHA SystemMirror tries to perform some operations (DLPAR or adjust the CoD and EPCoD resources) in parallel to the release of resources on the source node and the acquisition of resources on target node if the user allows it in the tunables (the value of Force synchronous release of DLPAR resources  is No ). 

Table 6-15 shows the testing results of the DLPAR operation. The result might be different in other environments, particularly if the resource is being used. 

There is one LPAR. Its current running CPU resource size is 2C, and the running memory resource size is 8 GB. The DLPAR operation includes add and remove. 

<img src='content_image/972739.jpg'>

## AIX ProbeVue maximum pinned memory setting 

ProbeVue is a dynamic tracing facility of AIX. You can use it for both performance analysis and problem debugging. ProbeVue uses the Vue programming language to dynamically specify trace points and provide the actions to run at the specified trace points. This feature is enabled by default. There is one restriction regarding ProbeVue’s maximum pinned memory and DLPAR remove memory operation: The Max Pinned Memory For ProbeVue tunable cannot  cross the 40% limit of system running memory. 

For example, you configure one profile for an LPAR with 8 GB (minimum) and 40 GB (wanted). When you activate this LPAR, the maximum pinned memory of ProbVue is set to 4 GB (10% of system running memory), as shown in Example 6-5. 

From AIX 7.1 TL4 onward, the tunables are derived based on the available system memory. The maximum pinned memory is set to 10% of the system memory. It cannot be adjusted when you restart the operating system or adjust the memory size with the DLPAR operation. 

# probevctrl -l Probevue Features: on --> ProbeVue is enabled at this time MAX pinned memory for Probevue framework(in MB): 4096 --> this is the value that we are discussing ... 

Now, if you want to reduce the memory 40 - 8 GB, run the following command: 

chhwres -r mem -m r1r9m1-9117-MMD-1038B9P -o r -p ITSO_S2Node1 -q 32768 

The command fails with the error that is shown in Example 6-6 on page 195. 

