System information

28 Logical Partitions on System i5
When the partition is activated, the configured memory is assigned to them and the Hardware
Page Table (HPT) is created by Power Hypervisor.
Memory allocation must be calculated precisely, in order to avoid lack of memory, which
could have an impact to the logical partition performance. If the memory allocation for all
logical partitions is not calculated precisely, the last powered on logical partition will receive
less memory than the configured amount of memory. If the minimum memory requirement for
the last powered on logical partition is not met, the logical partition could not be started.
From the managed system properties, the memory status can be viewed. Figure 1-24 shows
the memory information for the current managed system. It provides much information, for
example, Installed Memory, which displays the total number of memory units that are
installed on the managed system. Current memory available for partition usage is an amount
of memory that is available for use by all the logical partitions configured in the managed
system. This value will vary depending on the number of logical partitions configured and the
memory installed on the managed system. Partition memory usage displays current memory
in use by all active logical partitions.
Figure 1-24 Managed system memory information
For example, partition name 2 has the memory configuration as shown in Figure 1-25.
When the logical partition was powered on, it received all desired memory, which is
10240 MB + 512 MB = 10752 MB. This value can be found in the managed system memory
information shown in Figure 1-25.