IBM I5/OS - Manual (Page 18)

i Series. my Series.
Main Storage Concepts
Memory Allocation Facts
Power4 Hypervisor allowed memory manipulation at the single megabyte (1MB) level
Memory in the Power5 machines cannot be manipulated that finely :
Memory must be assigned or moved in blocks
Theses blocks are called “Logical Memory Blocks (LMB)” or “Memory Regions”
About those “Memory Regions” :
LMB are sized in multiples of 16 MB
Future implementations will allow use of 16, 32, 64, 128 or 256 MB blocks
LMB size is a system-wide parameter
LMB is the smallest amount of memory that can be manipulated
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i Series. my Series.
Main Storage Concepts
Memory Allocation Facts
Hypervisor uses memory to run the system !
Hypervisor memory used expands and contracts based on many variables :
Number of partitions
Amount of I/O attached to the system
Amount of virtual I/O slots used in each partition
HSL OptiConnect and Virtual OptiConnect links
Starting and/or stopping a partition affects hypervisor memory requirements
Hypervisor memory allocation made by 16 MB increments
Main Storage
P1 P2 P3
Hypervisor HPT1 HPT 2 HPT 3
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