eG Monitoring
 

Measures reported by pSeriesMemTest

The physical memory resources installed on a pSeries server are allocated to each LPAR on the server based on partition configuration, I/O resources assigned, and applications used. In addition to this, the system firmware will have to be configured with adequate memory resources for initialization and configuration of the server and for supporting the LPARs. Firmware is “software” stored in a memory chip that holds its content without electrical power, such as, for example, read-only memory (ROM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), and non-volatile random access memory (non-volatile RAM).

This test captures the memory usage of the system firmware and the physical memory allocations to the LPARs so that, in the event of a memory contention, administrators are enabled to determine what could be causing the contention - is it because the system firmware has not been configured with adequate memory resources, or is it because sufficent memory has not been allocated to the partitions.

Measurement Description Measurement Unit Interpretation
Installed_sys_mem The total amount of memory (in MB) installed on the managed system MB  
Sys_firmware_mem The amount of memory configured for the system firmware (i.e., the hypervisor) MB The amount of memory that is required by the server firmware varies according to several factors. Factors influencing server firmware memory requirements include:
  • Number of logical partitions;
  • Partition environments of the logical partitions;
  • Number of physical and virtual I/O devices used by the logical partitions;
  • Maximum memory values given to the logical partitions;

Generally, you can estimate the amount of memory that is required by server firmware to be approximately eight percent of the system installed memory. The actual amount that is required will generally be less than eight percent. However, there are some server models that require an absolute minimum amount of memory for server firmware, regardless of the previously mentioned considerations.

In the absence of adequate memory, the firmware may not be able to support LAPAR operations, and may even bring the server down.
Curr_avail_sys_mem The amount of physical memory that is yet to be allocated to the LPARs MB  
Used_mem The amount of physical memory that has been allocated to the LPARs MB Memory requirements for partitions depend on partition configuration, I/O resources assigned, and applications used. Memory can be assigned in increments of 16 MB, 32 MB, 64 MB, 128 MB, and 256 MB. The default memory block size varies according to the amount of configurable memory in the system. The detailed diagnosis of this measure reveals the minimum and maximum memory configurations of each LPAR on the server, and also the amount of memory that each LPAR is entitled to receive (i.e., current memory). With the help of this information, you can quickly isolate those LPARs that may have been under-sized or over-sized in terms of memory resource allocations.
Total_mem_utilzation The percentage of physical memory that has been allocated to the LPARs Percent Memory requirements for partitions depend on partition configuration, I/O resources assigned, and applications used. Memory can be assigned in increments of 16 MB, 32 MB, 64 MB, 128 MB, and 256 MB. The default memory block size varies according to the amount of configurable memory in the system.