Glossary

An event. A message sent to warn a user or application when certain conditions are met.

A monitor that monitors resource instances (or resource class) asynchronously. It is event driven and send notifications when events occur. It does not keep track of the current state or value of each resource it monitors.

The application that creates or cancels requests to monitor particular resources. The consumer of a resource status message. A user of the Resource Monitor framework. This user may browse resources, request status, and make requests to have resources monitored. Examples are MC/ServiceGuard as it starts a package or the SAM interface to EMS.

(Event Monitoring Service) The interface between resource monitors, the client and target applications.

A set of APIs together with the Registrar process and the resource dictionary, which allow client applications to request that resources be monitored and a target application be notified.

A command line utility that is used to configure and manage persistent monitoring requests for Event Monitoring Service (EMS) monitors, such as, HA Monitors, Hardware Monitors and Kernel Monitors.

An alert.

High Availability.

HP OpenView IT/Operations, formerly known as Operations Center. It is a software application that provides central operations and problem management for a multi-vendor distributed system.

The basic allocation unit for a logical volume is called a logical extent. For mirrored logical volumes, either two or three physical extents are mapped for each logical extent, depending on whether you are using 2-way or 3-way mirroring.

A collection of disk space from one or more disks. Each collection appears to the operating system as a single disk. Like disks, logical volumes can be used to hold file systems, raw data areas, dump areas, or swap areas. Unlike disks, logical volumes can be given a size when they are created, and a logical volume can later be expanded or reduced. Also, logical volumes can be spread over multiple disks.

(Logical Unit Numbers) A logical disk device composed of one or more physical disk mechanisms, typically configured into a RAID level.

(Logical Volume Manager) Manages disks in volume groups, and allows you to create logical and physical volume groupings.

(Management Information Base). A document that describes objects to be managed. A MIB is created using a grammar defined in "Structure of Management Information" (SMI) format. This grammar concisely defines the objects being managed, the data types these objects take, descriptions of how the objects can be used, whether the objects are read-only or read-write, and identifiers for the objects.

A MIB that defines information about the system, the network interface cards it contains, routing information it contains, the TCP and UDP sockets it contains and their states, and various statistics related to error counts. This MIB is widely adopted and is served by most IP-addressed devices. Most system and network resources managed by EMS are taken from this MIB.

See resource monitor.

See alert.

LVM divides each physical disk into addressed units called physical extents.

A disk that has been initialized by LVM.

The process by which a monitor obtains the most recent status of a resource.

A method of LVM configuration that allows you to provide redundant SCSI interfaces and buses to disk arrays, thereby protecting against single points of failure in SCSI cards and cables.

A grouping of physical devices (host adapters, busses, controllers, or disks), that allow LVM to manage redundant links or mirrored disks and access the redundant hardware when the primary hardware fails.

The registrar process provides the link between resource status consumers (clients) and resource status providers (resource monitors). The central part of the resource monitor framework which uses the resource dictionary to act as an intermediary between client systems and resource monitors.

May be any entity a monitor application developer names. Examples include a network interface, CPU statistics, a MIB object, or a network service.

A category of resources useful during configuration. For example, /net/interfaces/lan/status is provided as a resource class.

A file describing the hierarchy of resources that can be monitored and the processes that perform the resource monitoring.

The actual resources that can be monitored. For example, /net/interfaces/lan/status/lan0 may refer to a particular network interface installed on the monitored system.

A framework for selecting resources of interest and monitoring them according to the user's criteria. When the resource value matches the user's criteria, a notification is sent according to the user's instructions.The process that is used to obtain the status of a resource and send event notifications if appropriate. A monitor checks resources on the local system. The resource monitor maps the physical resource into a standard interface understood by EMS.

(Simple Network Management Protocol) Standard protocol for network based retrieval of information about system resources.

The current value of a resource (UP or DOWN). For some resource instances, a monitor may need to maintain a history of past events or conditions in order to know the resource value. In this case, a monitor is said to be maintaining state information. Stateless monitors do not keep any history of past conditions.

The target application is notified when a monitored resource reaches the condition for which notification was requested. For example, a target application could be MC/ServiceGuard or IT/Operations (ITO).

In LVM, a set of physical volumes whose extents are grouped together and then made available to users as logical volumes. A volume group can be activated by only one node at a time unless you are using MC/LockManager. MC/ServiceGuard can activate a volume group when it starts a package. A given disk can belong to only one volume group. A logical volume can belong to only one volume group.