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Updated: 11 December 1998

OpenVMS System Manager's Manual


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Appendix C
Compaq MIB Subagents Implemented on OpenVMS Alpha

The Extensible Simple Network Management Protocol (eSNMP) allows network managers to manage many different types of devices across all network and vendor boundaries through the use of databases called Management Information Bases (MIBs). Essentially, information is exchanged between master agents and subagents, which are devices such as routers and servers on the network being managed, and managers, which are the devices on the network through which the management is done.

This appendix describes the Compaq Server MIB and the Compaq Cluster MIB.

C.1 Compaq Server MIB Subagents

The Compaq Server MIB (DSM) consists of two extensions, or subagents:
Extension Describes
System A management interface to Alpha system information not defined by standard MIBs
Management Instrumentation in the Compaq extension agent, including the ability to detect and monitor thresholds on integer variables

The representation of the DSM within the standard Structure of Managed Information (SMI) framework is:


iso(1) org(3) dod(6) internet(1) private(4) enterprises(1) 36 

OpenVMS Alpha Version 7.1-1H1 and later implements the DSM subagents on the AlphaServer 800, 1000, 4000, 4100, 8200, and 8400 systems. With the DSM subagents, customers can remotely determine and manage important information such as:

Use the following software to access the DSM subagents:

The following sections describe the DSM subagents and explain how to set up your system to use them.

C.1.1 Overview of DSM Subagents

DSM subagents respond to SNMP requests for a DSM object --- the data item that the network manager is concerned with, or a trap --- information about a change of status. A subagent is responsible for reporting on and maintaining the data pertaining to these objects and traps.

The DSM system subagent implements the objects listed in Table C-1. Each object corresponds to a group of base system and environmental information relevant to OpenVMS Alpha networking and can be accessed by a network manager through ServerWORKS Manager.

Table C-1 DSM System Subagent Objects Implemented on OpenVMS Alpha
Object Data Type Access Description
MIB Information Group
svrSysMibMajorRev Integer Read only The major revision number of this implementation of the svrSystem MIB. Currently 1.
svrSysMibMinorRev Integer Read only The minor revision number of this implementation of the svrSystem MIB. Currently 0.
Base System Description Group
svrSystemModel DisplayString Read only System and model name. For example, AlphaServer 2100.
svrSystemDescr DisplayString Read only General text description of system type.
svrSystemBoardFruIndex Integer Read only The index of the Field Replaceable Unit (FRU) in the FRU table describing the serial number and other asset information of the board. If unknown, 0.
svrSystemBootedOS Integer Read only The current booted operating system.
svrSystemShutdownReason DisplayString Read only The possible reason for the system shutdown.
svrFirmwareIndex Integer Read only An index value unique to the local system.
svrFirmwareDescr DisplayString Read only Descriptive text for items such as the SRM console, ARC console, and system BIOS.
svrFirmwareRev DisplayString Read only A version number, often of the form V x.y or V x.y-z.
svrFwSymbolName DisplayString Read only The symbol name as visible on the console.
svrFwSymbolValue Octet string Read only The symbol value. Null if none or unknown.
System Processor Group
svrCpuIndex Integer Read only An index value for the CPU entry that is unique to the local system.
svrCpuManufacturer DisplayString Read only The manufacturer of the processor.
svrCpuRevision DisplayString Read only Version information in processor-specific format.
svrCpuFruIndex Integer Read only The index of the FRU entry in the FRU table that describes the asset information of the component containing the processor. If unknown, 0.
svrCpuCacheIndex Integer Read only The local index value.
svrCpuCacheLevel Integer Read only Level 1, level 2, level 3 cache, other, or unknown.
svrCpuCacheType Integer Read only Type of cache: internal, external, internal instruction, or internal data.
svrCpuCacheSize Kbytes Read only Cache size in Kbytes.
svrCpuCacheSpeed Integer Read only Cache speed in nanoseconds. If unknown, 0.
svrCpuCacheStatus Integer Read only Current status of the cache: enabled, disabled, other, or unknown.
Memory Configuration Group
svrPhysicalMemorySize Kbytes Read only Total amount of physical memory as seen by the operating system.
svrPhysicalMemoryFree Kbytes Read only Amount of free physical memory.
svrMemIndex Integer Read only Unique index for this entry.
svrMemSize Kbytes Read only Length of memory range.
svrMemFruIndex Integer Read only Index of the FRU entry in the FRU table on which the memory resides. If unknown, 0.
svrBusIndex Integer Read only An index value that is unique to the local system.
svrBusType BusTypes Read only Bus type.
svrLogicalSlotNumber Integer Read only Unique logical slot number on a given bus.
svrLogicalSlotDescr DisplayString Read only Device description derived from ID or as set by the management station.
svrLogicalSlotRevision DisplayString Read only Vendor-supplied major and minor revision of device in the slot.
Physical Configuration Group
svrFruIndex Integer Read only An index value that is unique to the system.
svrFruType Integer Read only General category of FRU type.
svrFruDescr DisplayString Read only Detailed description of the FRU type, if known.
svrFruVendor DisplayString Read only Manufacturer's name or ID.
svrFruPartNumber DisplayString Read only Order number for this unit.
svrFruRevision DisplayString Read only Version number of the unit. If an illustration is available, it appears as "Artwork: XXX" following the FRU version number.
svrFruFirmwareRevision DisplayString Read only Revision of the firmware, if applicable. Otherwise, null.
svrFruSerialNumber DisplayString Read only Unit's serial number.
Environment Group: Thermal
svrThermalSensorCount Integer Read only Number of thermal sensors present and readable in the system.
svrThSensorIndex Integer Read only An index value unique to the local system.
svrThSensorReading Integer Read only Current value read by the sensor in units as described by the svrThSensorReadingUnits object.
svrThSensorReadingUnits ThermUnits Read only Value of sensor in degrees Fahrenheit, Celsius, or relative value. If not available, value will be unknown.
svrThSensorStatus Integer Read only The sensor's status value.
Environment Group: Cooling
svrFanCount Integer Read only The number of fans whose states are detectable.
svrFanIndex Integer Read only An index value unique to the local system.
svrFanStatus Integer Read only Current fan status.
Environment Group: Power Supply
svrPowerSupplyCount Integer Read only Number of detectable power supplies reflected as entries in the svrPowerSupplyTable object.
svrPowerSupplyIndex Integer Read only An index value unique to the local system.
svrPowerSupplyStatus Integer Read only Current state of the power supply.

The DSM Management subagent implements the objects and traps listed in Tables C-2 and C-3, respectively.

Each object or trap corresponds to a group of management areas relevant to OpenVMS Alpha networking and can be accessed by a network manager through ServerWORKS Manager.

Table C-2 DSM Management Subagent Objects Implemented on OpenVMS Alpha
Object Data Type Access Description
MIB Information Group
svrMgtMibMajorRev Integer Read only The major revision number of this implementation of the svrMgt MIB. Currently 1.
svrMgtMibMinorRev Integer Read only The minor revision number of this implementation of the svrMgt MIB. Currently 0.
Alarms Group
svrAlarmNextThrIndex Integer Read only The next available index for creating a svrThrEntry object. If the value is -1, the maximum number of thresholds has been reached. A threshold record cannot be created until you delete the current threshold record.
svrAlarmEnableTraps Boolean Read/write If true, a trap is sent for each triggered alarm.
svrThresholdTable Sequence of SvrThresholdEntry Not accessible The threshold table that describes conditions for setting and resetting alarms. The agent checks this table for exceptions.

You can set alarms on absolute values (such as the current integer value of the sampled variable) or on delta values (such as the difference between the current or last value). Alarms can be Greater Than exception alarms, Less Than exception alarms, Equal To alarms, and so on. (See the svrThrAlarmType object description.)

Hysteresis (the tendency of certain binary devices to show different threshold values when changing from 0 to 1 than when changing from 1 to 0) is introduced by providing thresholds both for setting and resetting of the alarm state, thereby limiting the number of traps that are sent on alarm triggering.

You can create alarms to persist across agent reboots; however, this is not recommended for dynamic table variables.

The triggering of an alarm changes a state variable in the conceptual row and can also trigger the sending of a trap, or the local logging of an event.

svrThresholdEntry SvrThresholdEntry Not accessible A threshold alarm set on an integer variable.

An alarm entry is created by the management console using the current value of svrAlarmNextThrIndex to name the instances of the row variables, setting the svrThrStatus to underCreation. When you create a threshold entry for the first time, issue a set request on svrThrStatus.

You can set the remaining row variables in the same operation or in subsequent operations. Those not set retain their default values as described. You must set variable values for the following objects in the Alarms group before you enable the alarm:

  • svrThrStatus (set to underCreation)
  • svrThrVariableName through svrThrSeverity (set appropriately; see the object descriptions)
svrThrIndex Integer Read only An index value unique to the local system. On creation, set to the value of svrAlarmNextThrIndex.
svrThrStatus Integer Read/write Describes the status of the row.

When the row is created with the initial set, you must set svrThrStatus to underCreation. When the management console has completed the row setup, it sets this variable to rowEnabled. Variables in the row can only be written if svrThrStatus is in the initial underCreation state or has been set to rowDisabled.

To delete the row, set the status to rowInvalid. Be aware that errors in variable polling and threshold checking that cannot be corrected cause a row status change to rowError. Once the status is set to rowError by the agent, the agent does not reset the status. Instead, the management console must reset the status based on information returned with svrThrErrorValue or for other reasons.

svrThrVariableName Object identifier Read/write The object identifier (OID) of an integer variable to be tested against the threshold. At row creation, the variable equals the value 0.0 and must be set to the OID of an integer variable before enabling the alarm.
svrThrValueType Integer Read/write Absolute or delta value. The default on row creation is absoluteValue. The deltaValue is calculated by taking the current value and subtracting the svtThrLastValue value.
svrThrAlarmType Integer Read/write An alarm that signals a threshold whose value is Greater Than, Greater Than or Equal To, Equal To, Less Than or Equal To, or Less Than. The default value on row creation is Greater Than.

Greater Than or Greater Than or Equal To thresholds for absolute values occur when the sample value equals or exceeds the svrThrThresholdValue and svrThrAlarmState was reset. This condition causes svrThrAlarmState to be set and, if svrAlarmEnableTraps is true, a svrThrExceptTrap is sent. SvrThrAlarmState is reset when the sample value falls below or equals svrThrResetValue.

Less Than or Less Than or Equal To thresholds for absolute values occur when the sample value falls below or equals the svrThrThresholdValue, and svrThrAlarmState was reset. This condition causes the svrThrAlarmState to be set and, if svrAlarmEnableTraps is true, a svrThrExceptTrap is sent. SvrThrAlarmState is reset when the sample value exceeds or equals svrThrResetValue.

Equal To thresholds for absolute values occur when the sample value equals svrThrThresholdValue and svrThrAlarmState was reset. This condition causes the svrThrAlarmState to be set and, if svrAlarmEnableTraps is true, a svrThrExceptTrap is sent. SvrThrAlarmState is reset when the sample value does not equal svrThrResetValue.

The same conditions apply for delta values as for absolute values except the difference between the sample value and the svrThrLastValue is used for comparison with both the svrThrThresholdValue and the svrThrResetValue. Note that it is possible to have negative delta values since the difference is computed as the current value minus the svrThrLastValue.

svrThrSampleInterval Integer Read/write The interval (in seconds) between polls to check for threshold exceptions. The default value on row creation is 30 seconds. Minimum value: 1.
svrThrPersistent Boolean Read/write If true, the threshold persists across agent restarts. Default on row creation: false.

By default, the files used to store persistent data are SYS$SYSTEM:TCPIP$MGT_THRESHOLDS.DAT and SYS$SYSTEM:TCPIP$MGT_THRESHOLDS.BAK. To move the files off the system disk or rename them, the system manager can define the logical names TCPIP$MGT_PERSISTENCE_DAT and TCPIP$MGT_PERSISTENCE_BAK in the SYS$MANAGER:SYLOGICALS.COM file as appropriate. For example, to point to files in a different location, add the following definitions to SYS$MANAGER:SYLOGICALS.COM. (The examples are formatted to fit the table column.)

$ DEFINE/SYS -

_$ TCPIP$MGT_PERSISTENCE_DAT -
_$ DISK2:[SNMP.MIB]PERSIST.DAT;
$ DEFINE/SYS -
_$ TCPIP$MGT_PERSISTENCE_BAK -
_$ DISK2:[SNMP.MIB]PERSIST.BAK;
svrThrThresholdValue Integer Read/write The threshold value that is compared to the current or delta value. Default on row creation: 0.
svrThrResetValue Integer Read/write The value used to reset the threshold on all svrThrAlarmTypes objects except those that are Equal To. Default on row creation: 0.
svrThrLastValue Integer Read only The previous sample needed to evaluate if alarm should be triggered or to evaluate delta values for threshold checking.
svrThrAlarmState Integer Read only Indicates whether the alarm is currently set or reset. Used by polling management applications to determine if a threshold exception state has been detected based on the alarm definition. Has an initial value of reset when the alarm is enabled or the agent is restarted.

The value is reset if svrThrStatus changes to rowDisabled or rowInvalid. For guidelines on state changes, see the description for svrThrAlarmType.

svrThrLogEvent Boolean Read/write If true, logs data to the subagent process log file; for example, to [TCPIP$SNMP]TCPIP$SVRMGT_MIB.LOG. (See Section C.1.2.) Default value: false.
svrThrDescr DisplayString Read/write Describes the type of threshold. Set by the management console, not by the agent.
svrThrErrorValue SnmpErrors Read only The SNMP-defined error status that caused the svrThrStatus value to become equal to rowError. Valid only at that time.
svrThrComparisonName Object identifier Read/write An object identifier (OID) to a descriptor attribute used with the svrThrPersistent value to verify that the svrThrVariableName instance is correct. Optional. Default: 0.0.

On agent restarts, the value is retrieved and compared to the svrThrComparisonValue. If not equal, the OID instancing for svrThrVariableName might be incorrect. If this situation occurs, svrThrStatus is set to rowError and svrThrErrorValue to badValue.

svrThrComparisonValue DisplayString Read/write Date value of svrThrComparisonName. Optional. Used when svrThrPersistent is set. The value is compared to the current value on agent restarts. Default: null.
svrThrSeverity Severity Read/write Indicates the severity of the threshold. Default on row creation: informational.

Table C-3 DSM Management Subagent Traps Implemented on OpenVMS Alpha
Trap Variable Description
Local Server Control Group
svrThrHighExceptTrap svrThrVariableName
svrThrValueType
svrThrThresholdValue
svrThrLastValue
svrThrDescr
A high severity trap. The value that caused the alarm to occur is returned in svrThrLastValue.
svrThrMediumExceptTrap svrThrVariableName
svrThrValueType
svrThrThresholdValue
svrThrLastValue
svrThrDescr
A medium severity trap. The value that caused the alarm to occur is returned in svrThrLastValue.
svrThrLowExceptTrap svrThrVariableName
svrThrValueType
svrThrThresholdValue
svrThrLastValue
svrThrDescr
A low severity trap. The value that caused the alarm to occur is returned in svrThrLastValue.
svrThrInformationalExceptTrap svrThrVariableName
svrThrValueType
svrThrThresholdValue
svrThrLastValue
svrThrDescr
An Informational severity trap. The value that caused the alarm to occur is returned in svrThrLastValue.


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