This section explains the VMware overcommit function for L-Servers.
Overcommit
The VMware overcommit function for the CPU and memory is available on Resource Orchestrator.
The VMware overcommit function for the CPU and memory virtually allows a guest OS to use more resources than that of the actual CPU and memory of a server.
Resource Orchestrator provides the following functions to utilize the VMware overcommit function for the CPU and memory when creating L-Servers.
Creating an L-Server with the overcommit function for the CPU and memory
CPU Performance
The maximum number of CPU resources to be allocated to a virtual machine (Limitation)
CPU Reservation Performance
The minimum number of CPU resources to be reserved for a virtual machine (Reservation)
CPU Shares
The relative proportion for allocation of CPU resources when there are competing virtual machines (Share)
Memory Size
Memory Reserved
The maximum amount of memory resources to be allocated to a virtual machine (Limitation)
Memory Size
The maximum amount of memory resources to be allocated to a virtual machine by the VM host (Memory Size)
For the virtual L-Server created using Resource Orchestrator, the same value is set for both Memory Reserved and Memory Size.
Memory Reservation Capacity
The minimum amount of memory resources to be reserved for a virtual machine (Reservation)
Memory Shares
The relative proportion for allocation of memory resources when there are competing virtual machines (Share)
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.
Calculation of available space on VM pools, which uses values set for CPU reservation performance and memory reservation capacity
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.
Display of the number of L-Servers that can be created for a VM pool with overcommit attributes
For a VM pool with overcommit attributes, the number of L-Servers that can be created based on the CPU reservation values and memory reservation capacity specified in the L-Server template can be displayed.
For details on an L-Server, refer to "1.2.3 L-Servers" and "L-Server Creation" of "E.2.5 Setup" or "Chapter 10 Creating L-Servers" of the "User's Guide for Infrastructure Administrators (Resource Management) CE".
For details on resource pools, refer to "1.2.2 Resource Pool" or "Chapter 12 Resource Pool Operations" of 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 "12.4 Viewing a Resource Pool" of the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Prerequisites
Admin Server
When using the function for coordination with Resource Orchestrator, VMware, 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 "12.2 Resource Pool Operations" of the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Note
For the VM pool for overcommit, register only VM hosts that support overcommit (VMware, Hyper-V, or RHEL-KVM). If VM hosts other than VMware, Hyper-V, or RHEL-KVM have been registered, move those VM hosts to another VM pool.
The following operations cannot be performed on the VM hosts other than VMware, Hyper-V, or RHEL-KVM registered in the VM pool for overcommit.
Create an L-Server
Linking L-Servers with configured virtual machines
Create an Overcommit Configuration File for a VM Pool
For the VM pool created in 1., specify a reservation value or a maximum value after calculating the available space for the VM pool used for overcommit settings or performing overcommit.
Create an overcommit configuration file for a VM pool.
For details on definition files, refer to "E.1.1 Definition Files".
Point
When creating L-Servers that use overcommit and L-Servers that do not, both a VM pool that uses overcommit and a VM pool that does not must be created.
Create a VM Specific Information Definition File
Create a VM specific information definition file. Create a VM specific information definition file when configuring different settings for individual user groups without configuring overcommit settings on the L-Server template.
For details on creating VM specific information definition files, refer to "E.1.1 Definition Files".
Export an L-Server Template
For details on how to export L-Server templates, refer to "8.2.1 Exporting a Template" of the "User's Guide for Infrastructure Administrators (Resource Management) CE".
Edit an L-Server Template
Configure the overcommit settings for an L-Server template.
For details on the XML definition of L-Server templates, refer to "2.2.2 Virtual L-Server Templates" in the "Reference Guide (Resource Management) CE".
When configuring overcommit settings using the VM specific information definition file, do not configure the following parameters except "Enabling/disabling overcommit". When overcommit settings are configured in the L-Server template, priority is given to those settings.
CPU Reservation Performance
CPU Shares
Memory Reservation Capacity
Memory Shares
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.
Import an L-Server Template
For details on how to import L-Server templates, refer to "8.2.3 Importing a Template" of 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 5.
For details, refer to "10.1 Creation Using an L-Server Template" of 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 10 Creating L-Servers" of the "User's Guide for Infrastructure Administrators (Resource Management) CE", and then execute the rcxadm lserver create command.
For details on the rcxadm lserver command, refer to "1.3.1 rcxadm lserver" of the "Reference Guide (Resource Management) CE".
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".
For details on the rcxadm lserver command, refer to "1.3.1 rcxadm lserver" of the "Reference Guide (Resource Management) CE".
Note
When starting of an L-Server fails, the retrieval method varies depending on the L-Server settings.
Perform the following:
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 how to change the boot location, refer to "10.3 Creation of Virtual L-Servers Using Parameters" of the "User's Guide for Infrastructure Administrators (Resource Management) CE".
For details on how to move the boot location, refer to "11.7 Moving an L-Server between Servers (Migration)" of 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 on the rcxadm lserver command, refer to "1.3.1 rcxadm lserver" of the "Reference Guide (Resource Management) 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 reservation capacity.
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 use the appropriate commands to reflect the changes.
