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Definitions for Assigning (Adding) Or Deleting ILM or CLM Memory | |
Physical memory can be divided into two categories:
ILM and CLM. - ILM
Interleaved Memory, where memory consists of blocks
of memory from one or more cells of the nPartition. - CLM
Cell Local Memory, where memory consists of blocks
of memory from only a specific cell of the nPartition.
You can assign memory to a virtual partition by
any of the following methods: By size. This uses the nPartition’s ILM. The basic syntax
for this is: -a|d mem::size
By cell and a corresponding
size. This uses the specified cell’s CLM. The basic
syntax for this is: -a|d cell:cell_ID:mem::size
Definitions for Dynamically Migrating ILM or CLM Memory | |
| | | |  | NOTE: Dynamic memory migration may require a system
firmware upgrade. See the HP-UX Virtual Partitions Ordering
and Configuration Guide for details. | | | | |
When assigning (adding) or deleting either ILM
or CLM to a virtual partition, you can specify the memory as either base or float. - Base
Base memory cannot be deleted from a virtual partition when a virtual partition is up. When a virtual partition is up, base memory can only be added to a virtual
partition. To delete base memory, the target virtual partition
must be down. When the target
virtual partition is down, base memory can always be added to or deleted. To specify base memory, you can append :base or :b to the aforementioned assignment
specifications (see below). :base is the default. While there is no specific minimum base memory requirement per
vpar, the HPUX kernel does require a certain amount of base memory
to boot successfully. For information on how much this should be,
see the document Installing and Updating Guide for HP-UX
11i v3 (11.31). Appendix F, specifies
the minimum portion of the total memory in the virtual partition that
must be configured as base memory when the virtual partition is up. If the documented ratio is not maintained, the partition
boot or online addition or deletion of float memory may fail. - Float
Float memory can be added to as well as
deleted from a virtual partition while the virtual partition
is up or down. To specify float memory, you must append :float or :f to the memory assignment specification
(see below). The only exception is if you are deleting a user-specified
range of memory added as float, as memory ranges are unique. Therefore, if you wish to add and delete memory online (while the virtual partition
is up), you must specify :float or :f on the command line when you assign the memory; if you
do not specify :float or :f on the command line, that memory will
be assigned as :base (the default) in which case you will not be able
to delete the memory online. This is also true when you assign memory
during the creation of a virtual partition. If you do not specify :float during the creation of the virtual partition, all
memory assigned to the virtual partition will be considered as base. When you wish to delete float memory online, you must also specify :float or :f on the command
line; otherwise, because :base is the default, you will
be attempting to delete base memory, which is not allowed. When you wish to delete float memory offline, you must also specify :float or :f on the command
line; otherwise, because :base is the default, you will
be deleting base memory. There are no minimum requirements of vPars for float memory
assigned to a virtual partition.
The table below summarizes what you can do with
each type of memory. Table 6-1 Allowed Memory Migration Operations | | Base Memory | Float Memory |
|---|
vPar State | Add | Delete | Add | Delete | UP | Allowed | Not
Allowed | Allowed | Allowed | DOWN | Allowed | Allowed | Allowed | Allowed |
Syntax for Assigning (Adding) and Deleting Base and Float MemoryThe resulting syntax to specify memory as either
float or base is: - ILM/size:
-a|d mem::size[:b[ase]|f[loat]] - CLM:
-a|d cell:cell_ID:mem::size[:b[ase]|f[loat]] - Address:
-a|d mem:::base:range[:b[ase]|f[loat]]
| | | | | NOTE: The Default is :base. When neither :base or :float is specified, the default is :base. When you add memory as :float, you must specify
:float on the command line. Further, when you wish to delete float
memory, you must also specify :float on the command line, for example: # vparmodify -p keira3 -d mem::256:float |
If you do not specify :float when adding or deleting
memory, regardless of the state of the partition, the default of :base
is attempted. Mixed vPars Environments In a mixed HP-UX 11i v2/v3 vPars environment,
or a mixed HP-UX 11i v1/v2/v3 vPars environment, dynamic memory migration
is only supported on the vPars versions that support dynamic memory
migration. In other words, the both source and target virtual partitions must be running vPars A.05.xx. It is possible to perform add/delete memory operations
on virtual partitions running A.04.xx, as long as the target virtual
partition is in the down state. Note that
the vparmodify command must be executed on a virtual
partition running vPars A.05.xx. For more information on mixed HP-UX 11i v2/v3
vPars environments or mixed HP-UX 11i v1/v2/v3 vPars environments,
see “Mixed HP-UX 11i v2/v3 vPars Environments in vPars A.05.xx” or “Mixed HP-UX 11i v1/v2/v3 vPars Environments in vPars A.05.03”. | | | | |
Performance Note for Base versus Float Memory AmountsWhen a virtual partition contains more base memory,
this allows the OS to improve the memory performance of applications
since there is more locked memory at its disposal. When a virtual
partition contains more float memory in each virtual partition, this
allows the user the flexibility to move memory between partitions
based on the memory needs in each partition, but this will not be
locked memory. Note that similar to memory being reserved for
the kernel in a non-vPars OS instance, the OS kernel in a virtual
partition requires some amount of base memory to boot and run. See Appendix F, for a virtual partition’s
base memory requirement. For information on general memory management,
including locked memory, see the white paper HP-UX Memory
Management available at http://docs.hp.com. | | | | | NOTE: WLM and Dynamically Migrating Memory in vPars If WLM is managing the target virtual partition,
the WLM daemons wlmpard and wlmd should be stopped prior to execution
of the vparmodify command to migrate the memory.
For more information, see the WLM A.03.02 Release Notes at http://www.hp.com/go/wlm. Granules and Memory Migration When memory is deleted from an UP virtual partition,
the actual amount deleted may not be what is specified on the command
line. First, memory is always migrated (added or deleted) in terms
of memory granules. The vPars Monitor rounds up to the next granule
size. For example, if a 100 MB memory deletion request is made
and the memory granularity is set to 256 MB, 256 MB will
be deleted - not 100 MB. If a 257 MB deletion is requested,
512 MB will be deleted. To minimize any unintended changes, you
can perform memory migrations in terms of multiples of the granule
size. Another reason for a difference between the specified
amount on the command line and the actual amount is memory alignment:
whether the target virtual partition has float memory granules that
are aligned on a granular boundary. In a vPars system, a few memory granules may not
conform to the specified granule size. For example, even if the specified
granule size is 256 MB, there may be memory granules that are
less than 256 MB. Within a granule, the firmware may use a portion
of the memory granule even before the vPars Monitor boots, or memory
pages in the system may be bad due to double bit memory errors. For example, if we have the following configuration: The specified ILM granule
size is 256 MB. vpar1 contains 500 MB
of float memory made up of two granules, 256 MB and 244 MB.
If you request a deletion of 244 MB, the
vPars Monitor rounds up the request to the specified granule size
of 256 MB and passes the request to the OS kernel. The kernel
chooses one of the float memory granules for deletion. The chosen
granule can be either the 244 MB or 256 MB
granule. If the kernel chooses the 256 MB granule, then the amount
of memory that is deleted is different from the request of 244 MB.
The contrary is true, where if you request a 256 MB deletion,
the kernel may choose the 244 MB granule Again, the memory deleted
(244 MB) is different from the command line request of 256 MB. For further information on memory usage, see Appendix D. | | | | |
Advanced Topic: Granularity | |
Granularity refers to the unit size in which memory
is assigned to the all virtual partitions in a given vPars database
(vpdb). You should be careful when using the granularity option; using
the granularity option incorrectly can cause all the virtual partitions
to not be bootable. For information, see: |
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