vparresources.5 (2010 09)

v
vparresources(5) vparresources(5)
Note: When memory is deleted from an active partition, the kernel makes the decision on which
granules of memory is easier to delete. Hence, the granules that get deleted may not add upto the
memory that was requested. For example, if the granule size is 1024MB and there are two floating
memory granules 1024MB and 580MB (a granule with memory hole) and the user requested delete of
580MB, after aligning the request the kernel/monitor might pick either 1024MB or 580MB granule to
delete. If all or some of the deleted memory happens to fall within a user-specified floating range, the
remainder of the range is converted from user-specified to monitor-assigned range.
Default memory granularity in A.05.01 for Itanium-based platforms
The default memory granularity chosen by the vPars software is based on the total memory in the hard
partition. The minimum default value is 128MB which is same as the default value in A.04.01. However,
if the memory in the hard partition is too large to fit into the supported number of memory granules for
the hard partition, then the next higher supported memory granularity value is chosen as the default
memory granularity. This is done at the time of a new database creation. For example,
If a hard partition contains 64G of interleaved memory and the maximum number of supported ILM
memory granules on the system is 1024, then the default memory granularity chosen is 128MB.
If a hard partition contains 192G of interleaved memory and the maximum number of supported ILM
memory granules on the system is 1024, then the default memory granularity chosen is 256MB.
Note: The above default value is determined by the vPars software when the vpar database is created
for the first time. When new memory is added to the hard partition, memory granularity is not automati-
cally recalculated.
Note: In certain scenarios, vPar command may not be able to calculate the default granularities accu-
rately. In these cases, a default of 128MB will be chosen and a warning message asking the user to vali-
date the granularity manually will be issued.
Performance impacts of memory granularity in A.05.01
Note: This section applies only for Itanium-based platforms.
There are no OS boot time performance issues in HP-UX Release 11i, Version 3 related to the memory
granularity chosen for the system. Difference in OS boot time on the same system with 128MB granular-
ity and 1024MB granularity is close to insignificant. Hence, you do not have to set a higher memory
granularity value for large memory systems with A.05.01 running HP-UX Release 11i, Version 3. How-
ever, if any of the vPars is running HP-UX Release 11i, Version 2, then higher memory granularity value
may have to be chosen to improve the boot time for the HP-UX Release 11i, Version 2 vPar.
Memory granularity changes after memory addition to the hard partition
Note: This section applies only for Itanium-based platforms.
When new memory is added to the hard partition and if the number of memory granules on the system
based on the current memory granularity value exceeds the maximum supported memory granules on the
system, then the vPar database has to be manually recreated. At the time of manual database recreation,
a new memory granularity value will be chosen by the vPars software which works with the total memory
on the system. For example,
If you added 32G to a 64G system and the memory granularity was 128MB, there is no change required,
since the total number of granules based on 128MB is still under 1024.
If you added 64G to a 96G system and the memory granularity is 128 MB, you are exceeding the 1024
limit for the maximum number of granules supported for the system and you have to recreate the data-
base. The new granularity chosen by the vPars software will be 256MB for this case.
The above examples are assuming that memory is added as ILM for a system having 1024 as the sup-
ported maximum number of ILM memory granules. Similar adjustments have to be made if new memory
is added as CLM.
Assigning Memory Quantity
The
-a mem::size[:b[ase]|f[loat[ing]]] option is used to assign size MB of base or floating ILM
to a vPar.
The
-a cell:cell_id:mem::size[:b[ase]|f[loat[ing]]] option assigns size MB of base or float-
ing CLM from cell cell_id to a vPar.
If base (or b) or floating (or float or f) is not specified, memory added or deleted will be treated as base
memory. Base memory (default) cannot be deleted when the vPar is Up. Floating memory can be deleted
HP-UX 11i Version 3: September 2010 − 7 − Hewlett-Packard Company 7