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About Logical Domains Software

Logical Domains software enables you to allocate the system resources of your server (such as a boot environment, CPUs, memory, and I/O devices) into logical domains. By using a logical domains environment, you can increase resource usage, improve scaling, and gain greater control of security and isolation.

LDoms software enables you to create and manage as many as 128 logical domains, depending on the hardware configuration of the server on which the Logical Domains Manager has been installed. You can virtualize resources and define network, storage, and other I/O devices as services that can be shared between domains.

A logical domain is a discrete logical grouping with its own operating systems, resources, and identity within a single computer system. Applications software can run in logical domains Each logical domain can be created, destroyed, reconfigured, and rebooted independently, without requiring a power cycle of the server. There are several roles that logical domains can perform as shown in the following table.

TABLE 4-1   Logical Domain Roles 

Domain Role	Description
Control domain	Domain in which the Logical Domains Manager runs, enabling you to create and manage other logical domains and allocate virtual resources to other domains. There can be only one control domain per server. The initial domain created when installing Logical Domains software is a control domain and is named primary.
Service domain	Domain that provides virtual device services to other domains, such as a virtual switch, a virtual console concentrator, and a virtual disk server.
I/O domain	Domain that has direct ownership of and direct access to physical I/O devices, such as a network card in a PCI Express controller. Shares the devices to other domains in the form of virtual devices. You can have a maximum of two I/O domains, one of which also must be the control domain.
Guest domain	Domain that is managed by the control domain and uses services from the I/O and service domains.

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Logical Domain Configurations

The current configuration of a logical domain can be stored on the service processor (SP). Using Logical Domains Manager CLI commands, you can add a configuration, specify a configuration to be used, and list the configurations on the service processor. You can also use the ILOM set /HOST/bootmode config=configfile command to specify an LDoms boot configuration. For further information about /HOST/bootmode, refer to the Integrated Lights Out Management 2.0 Supplement for the Sun Netra T5440 Server.

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Logical Domains Software Requirements

The following software is required or suggested for Logical Domains on the Sun Netra T5440 server:

• (Required) Logical Domains Manager 1.0.3 or above software

• (Suggested) Solaris Security Toolkit 4.2 software – Refer to the Solaris Security Toolkit 4.2 Administration Guide and Solaris Security Toolkit 4.2 Reference Manual for more information

  
  

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  Note - During the boot process, domains that use virtual boot devices must wait for their service domains to come online first. This can prolong the boot process.

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