This section explains the overcommit function for L-Servers.
Overcommit
Resource Orchestrator supports the Hyper-V overcommit function for the CPU and dynamic memory.
The Hyper-V overcommit function for the CPU allows virtual allocation of more resources than that of the actual CPU installed on a server to a guest OS.
Hyper-V dynamic memory allows virtual allocation of more memory than that of the actual memory installed on a server to a guest OS.
Note
When using the dynamic memory or the memory weight, the VM host must be one of the following:
Microsoft(R) Windows Server(R) 2008 R2 SP1 or later
Microsoft(R) Windows Server(R) 2012 or later
SCVMM must be one of the following in order to be able to manage the target VM hosts:
System Center Virtual Machine Manager 2008 R2 SP1 or later
System Center 2012 Virtual Machine Manager or later
If there is no VM host or SCVMM as above, creation and modification of L-Servers with dynamic memory and memory weight enabled will fail.
The guest OSs able to utilize dynamic memory are limited to particular Windows software versions. Refer to the Microsoft web site below.
URL: http://technet.microsoft.com/en-us/library/ff817651(WS.10).aspx |
When the VM host is Windows Server 2012 or later, it is not possible to set it from this product though the minimum memory value exists as a setting of the dynamic memory.
The same value as startup memory size is set.
Resource Orchestrator provides the following functions to utilize the Hyper-V overcommit function for the CPU and dynamic memory when creating L-Servers.
Creating an L-Server with CPU overcommit and dynamic memory configured
CPU Performance
The maximum number of CPU resources to be allocated to a virtual machine (Limitation)
CPU Weight
The priority of CPU allocated to a virtual machine
Memory size
Maximum Memory
The maximum amount of memory resources to be allocated to a virtual machine (Limitation)
Virtual Machine Memory
The maximum amount of memory resources to be allocated to a virtual machine by the VM host (Memory Size)
For virtual L-Servers created using Resource Orchestrator, set the memory size as follows, depending on the dynamic memory setting:
Set only the virtual machine memory.
Set only the maximum memory.
Dynamic Memory
Initial Memory Size
Initial memory size to be allocated at startup
Memory Buffer
Available memory to be reserved for a virtual machine as a buffer
Memory Weight
The priority of memory resources to be allocated to a virtual machine
Setting an overcommit attribute for a resource pool
Overcommit attributes can be set for resource pools. An L-Server with overcommit attributes can be created using overcommit attributes settings or a resource pool.
Deployment of L-Servers with more resources than those of the server
Creation of an L-Server with more resources than that of the actual CPU or memory installed on a server is possible.
Whether the resulting L-Server can be started depends on the resources available on the VM host.
Calculation of available space on VM pools, which uses values set for CPU reservation performance
Conversion of the free CPU capacity and free memory capacity of VM pools with overcommit attributes
For a VM pool with overcommit attributes, the conversion of free CPU capacity and free memory capacity can be displayed based on the CPU reservation values and memory allocation capacity of an L-Server created beforehand.
L-Server Conversion of a VM Pool with Overcommit Attributes
For the free CPU capacity and free memory capacity of a VM pool with overcommit attributes, L-Server conversion can be displayed based on the CPU reservation values and memory reservation capacity specified in the L-Server template.
For details on L-Servers, refer to "2.2.3 L-Server" in the "Design Guide CE", "8.3.7 Creating L-Servers", or "Chapter 16 Creating L-Servers" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
For details on resource pools, refer to "2.2.2 Resource Pools" in the "Design Guide CE", or "Chapter 20 Resource Pool Operations" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
For details on the available capacity view or the L-Server conversion view, refer to "20.6 Viewing" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Prerequisites
Admin Server
When using the function for coordination with Resource Orchestrator, Hyper-V, or the overcommit function for the CPU and memory, the only supported admin server OS is Windows.
Installation Procedure
Use the following procedure to install overcommit.
Create a VM Pool for Overcommit
For details on how to create a VM pool, refer to "Chapter 20 Resource Pool Operations" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Point
Refer to the "Point" described in "1. Create a VM Pool for Overcommit" in "Installation Procedure" in "8.2.11 Overcommit".
Note
Refer to the "Note" described in "1. Create a VM Pool for Overcommit" in "Installation Procedure" in "8.2.11 Overcommit".
Create the definition files.
Create a definition file (VM specific information definition file) when configuring different settings for individual user groups without configuring overcommit settings on the L-Server template.
For VM specific information definition files, refer to "8.1 Definition Files Commonly Shared when Creating Virtual L-Servers".
Export an L-Server template
For details on how to export L-Server templates, refer to "15.2.1 Export" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
L-Server template operations (steps 3 to 5) can be performed using the GUI.
For details on how to operate L-Server templates using the GUI, refer to "15.1 Operations Using the Wizard GUI" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Edit an L-Server Template
Configure the overcommit settings for an L-Server template.
Edit the XML definition of L-Server templates, referring to "15.2.2 Virtual L-Server Templates" in the "Reference Guide (Command/XML) CE".
When overcommit settings are configured in both the L-Server template and the VM specific information definition file
Priority is given to the settings in the L-Server template.
When configuring individual values for overcommit using the VM specific information definition file
Configure only the following element on the L-Server template.
Enabling/Disabling Overcommit
Do not specify the following elements:
CPU Reserved
CPU Weight
Initial Memory Size
Memory Buffer
Memory Weight
Information
If a template is imported without editing the L-Server template name, the content of the existing L-Server template is overwritten. If an L-Server template is imported after the name is edited from when it was exported, the L-Server template is added.
When editing an L-Server template, check the combination of enabling/disabling dynamic memory, initial memory size, and memory buffer.
When Dynamic Memory is Enabled
Initial memory size and memory buffer will be adopted when creating an L-Server
When Dynamic Memory is Disabled
Initial memory size and memory buffer will be ignored when creating an L-Server
Import an L-Server Template
For details on how to import an L-Server template, refer to "15.2.3 Import" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Create an L-Server
Create an L-Server using the L-Server template created in step 5.
For details, refer to "16.1 Creation Using an L-Server Template" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
When not using an L-Server template, create an L-Server using a command. Edit the L-Server XML referring to "Chapter 16 Creating L-Servers" in the "User's Guide for Infrastructure Administrators (Resource Management) CE", and then execute the rcxadm lserver create command.
For details, refer to "3.6 rcxadm lserver" and "15.2.2 Virtual L-Server Templates" in the "Reference Guide (Command/XML) CE".
Point
When you create an L-Server, which uses overcommit from the [Resource] Tab of the ROR console, specify an L-Server template.
Confirm the Overcommit Function Settings for an L-Server
To confirm overcommit settings configured for an L-Server, execute the rcxadm lserver show command.
Confirm that the command output result includes the line starting with "OverCommit: true".
Additionally, confirm the combination of the dynamic memory setting, initial memory size, and memory buffer.
For details on the rcxadm lserver command, refer to "3.6 rcxadm lserver" in the "Reference Guide (Command/XML) CE".
Note
When starting of an L-Server fails, the procedures vary depending on the L-Server settings. Perform the following procedures:
When [Boot Location] of the L-Server is set to [Relocate at startup]
Start the L-Server again. When there is a VM host with an available resource, the L-Server will start on that VM host after several attempts at startup.
When [Boot Location] of the L-Server is set to [Fixed]
As no VM host is automatically selected, start the L-Server after changing its boot location, or moving or stopping other L-Servers on the same VM host.
For details on changing the boot location, refer to "16.3 Creation of Virtual L-Servers Using Parameters" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
For details on moving the boot location, refer to "17.7 Migration between VM Hosts" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Changing L-Server Specifications
This section explains how to modify L-Server specifications.
To change L-Server specifications, execute the rcxadm lserver modify command.
For details, refer to "3.6 rcxadm lserver" in the "Reference Guide (Command/XML) CE".
Note
Changing of L-Server specifications will fail if the resources (the number of CPUs, CPU frequency, and memory capacity) of a physical server where a VM host operates are less than the CPU reservation performance and memory size.
When CPU performance and memory capacity are smaller than the CPU reservation performance and memory reservation capacity, modification of L-Server specifications fails.
When modifying specifications of an L-Server to which resources have been allocated, the information in the VM specific information definition file is not reflected because priority is given to the values already configured to the L-Server. In that case, enter the new values in the XML file and then execute the appropriate commands to reflect the changes.
