| Sun SNMP Management Agent for Sun Fire and Netra Systems |    
|
| Sun SNMP Management Agent for Sun Fire and Netra Systems |
|
| C H A P T E R 9 |
|
Sun SNMP Management Agent MIBs |
This chapter describes how the managed objects and their relationships are presented by the SNMP interface.
The chapter contains the following sections:
The SNMP agent supports both management agent system, and also a logical representation of the administrative domains within it, are provided by the ENTITY-MIB, as defined by RFC 2737, extended by the SUN-PLATFORM-MIB.
|
Note - Many of the objects defined in the MIBs have a MAX-ACCESS of read-write, but these objects are only writable where such an operation is appropriate to the component being modeled. |
The ENTITY-MIB contains the following groups, which describe the physical and logical elements of the managed system.
The entityPhysical group describes the physical entities--identifiable physical resources managed by the agent (for example, chassis, power supplies, sensors and so forth). These entities are represented by rows in the entPhysicalTable.
The entityLogical group describes the logical entities managed by the agent. These are representations of logical entities providing abstractions of service that can be managed by higher levels of management. These are primarily concerned with platform hardware management and include functions such as OS reboot, hardware reset and power control. Typically, they correspond to administrative domains such as Solaris domains or service controllers.
The entityMapping group identifies the relationship between the entityPhysical group and the entityLogical group.
The entityGeneral group provides the last change time stamp for the time when any entity in the Physical Entity Table or Physical Mapping Table is changed.
The entityMIBTraps group defines the entConfigChange notifications used to signal a change to the last change time stamp.
Chapter 7 provides an overview of how the generic elements of SNMP represent the Sun platform SNMP model.
The SunPSM physical model uses the ENTITY-MIB to provide a containment hierarchy of hardware entities. Each entity is modeled as a separate row of the ENTITY-MIB's entPhysicalTable.
FIGURE 9-1 shows an example of a physical containment hierarchy. The number in the bottom right corner gives the index to the corresponding row in the entPhysicalTable (TABLE 9-1).
This information is presented using SNMP tables:
This table provides a row per hardware entity. These rows are called Entries and a particular row is referred to as an instance. Each entry contains:
This table provides a virtual copy of the hierarchy of the hardware resources represented in the Physical Entity Table. This table is two-dimensional, indexed first by the entPhysicalIndex of the containing entry, and then by the entPhysicalIndex of each contained entry.
TABLE 9-1 shows the entPhysicalTable on which the above figure is based, and TABLE 9-2 shows the physical mapping.
The entPhysicalClass in an enumerated value that provides an indication of the general hardware type of a particular physical entity, each of which is represented by a row in the entPhysicalTable.
The following list describes the set of entPhysicalClass elements:
The enumeration other(1) applies if the physical entity cannot be classified by one of the following.
The chassis class represents an overall container for equipment. Any class of physical entity can be contained within a chassis.
The container class applies to a physical entity that can contain one or more removable physical entities, of the same or different type. For example, each empty or full slot in a chassis is modeled as a container. Field-replaceable units (FRUs), such as a power supply or fan, are modeled as modules within a container entity.
The power supply class applies to a component that can supply power, such as a battery.
The fan class applies if the physical entity is a fan or other cooling device.
The sensor class applies to a physical entity that is capable of measuring some physical property.
The module class applies to a self-contained sub-system, and which is modeled within another physical entity such as a chassis or another module. The entity is always modeled within a container
The sunPlat logical model uses the ENTITY-MIB to provide a list of logical entities. Each entity is represented as a separate row in the ENTITY-MIB's entLogicalTable.
|
Note - Unlike the physical model, the logical model is flat rather than hierarchical. |
The ENTITY-MIB does not distinguish between different classes of logical object, unlike the case for physical objects. The SUN-PLATFORM-MIB provides a class hierarchy for logical objects and this is described in Chapter 8.
The information in the entLogicalTable can be used to support multi-scoping using different naming context. However, this capability is not employed in this product. The information of particular value is the entLogicalDescription and entLogicalTAddress, the latter giving the IP address at which the logical entity can be accessed.
The ENTITY-MIB provides a mapping between logical objects and the physical objects of which they are composed. This is achieved by the entLPMappingTable, which is a two-dimensional table (similar to the entPhysicalContainsTable) and which identifies the physical entities that realize a given logical entity. These physical entities are identified by their entLPPhysicalIndex, which is equivalent to the entPhysicalIndex.
Although this table can potentially represent all the physical entities associated with a given logical entity, by convention, only the enclosing physical entity is referenced. For example, for a logical entity realized by a physical module, the mapping references only the module, not all the physical entities contained within it.
The ENTITY-MIB provides a single SNMP notification, entConfigChange, which is used to signal a change to any of the tables in the MIB. It is set to provide a maximum of one trap every five seconds.
The SUN-PLATFORM-MIB defines more specific notifications and these are described in Chapter 11.
The SUN-PLATFORM-MIB does the following:
|
Note - All objects in the SUN-PLATFORM-MIB have the prefix sunPlat to make them globally unique. |
The SUN-PLATFORM-MIB provides additional attributes from classes that are not represented in the Physical Entity Table. It extends the Physical Entity Table by adding the following sparsely populated table extensions:
This augments the Physical Entity Table to provide further information for managed objects of the Equipment class. This class is applicable for all Sun SNMP Management Agent hardware resources. Subclasses of the Equipment class are represented by further Table Extensions.
This extends the Equipment Table Extension. It provides the additional information relevant for managed objects of the container(5) entPhysicalClass.
This extends the Equipment Table Extension. It provides the additional information relevant for managed objects of the module(9) entPhysicalClass.
This extends the Physical Entity Table. It is used to supplement the entPhysicalClass column in the Physical Entity Table. If a resource has an entPhysicalClass of other(1), but is of a class modeled by sunPlat, that is, the Watchdog or AlarmDevice class, this table identifies its sunPlatPhysicalClass.
This extends the Equipment Table Extension. It provides the additional information relevant for managed objects of the entPhysicalClass sensor(8). Subclasses of Sensor class are represented by further Table Extensions and identified by this table using sunPlatSensorClass.
This extends the Sensor Table Extension. It provides additional information relevant for managed objects of the entPhysicalClass sensor(8) and sunPlatSensorClass binary(1).
This extends the Sensor Table Extension. It provides additional information relevant for managed objects of the entPhysicalClass sensor(8) and sunPlatSensorClass numeric(2).
This extends the Sensor Table Extension. It provides additional information relevant for managed objects of the entPhysicalClass sensor(8) and sunPlatSensorClass discrete(3).
This extends the Equipment Table Extension. It provides the additional information relevant for managed objects of the entPhysicalClass fan(7).
This extends the Equipment Table Extension. It provides the additional information relevant for managed objects of the entPhysicalClass other(1) and sunPlatPhysicalClass alarm(8).
This extends the Equipment Table Extension. It provides the additional information relevant for managed objects of the entPhysicalClass other(1) and sunPlatPhysicalClass watchdog(3), typically representing service indicator LEDs.
This extends the Equipment Table Extension. It provides the additional information relevant for managed objects of the entPhysicalClass powerSupply(6).
TABLE 9-3 shows an example of the Table Extensions to the Physical Entity Table. The entPhysicalIndex (column 1 in this table) is based on the example hardware resource hierarchy shown in FIGURE 9-1
The SUN-PLATFORM-MIB provides additional attributes from classes that are not supported in the Logical Entity Table. It extends the Logical Entity Table by adding the following sparsely populated table extension:
This extends the entLogicalTable to define the class of the logical entity, sunPlatLogicalClass, and its status, sunPlatLogicalStatus. The sunPlatLogicalTable is valid for all entries in the entLogicalTable. The Computer System subclass of the Logical class is represented by a further table extension:
This table extends the entLogicalTable to provide attributes common to instances of a computer system.
The sunPlatUnitaryComputerSystemTable is valid for those rows of the entLogicalTable with a sunPlatLogicalClass of computerSystem(2).
| Sun SNMP Management Agent for Sun Fire and Netra Systems | 817-2559-16 |
|
Copyright © 2006, Sun Microsystems, Inc. All Rights Reserved.