Host Resources MIB
obsoleted by
- rfc-2790 — Host Resources MIB
Extracted elements (30)
hrSystemUptime is defined separately from sysUpTime in MIB-II because sysUpTime reflects uptime of the network management portion of the system, whereas hrSystemUptime reflects the time since the host itself was last initialized — these can differ significantly.
The hrStorageTable represents logical storage areas as seen by applications rather than physical storage entities seen by the OS; tapes and floppies without file systems are excluded because they are not allocated in chunks to requesting applications.
The hrSWInstalledLastChange and hrSWInstalledLastUpdateTime objects exist because caching of installed software data is expected to be a popular implementation strategy; polling these timestamps allows a management station to determine when re-downloading the full table is warranted.
The ProductID textual convention uses OIDs so all products from one manufacturer are registered under a manufacturer-specific subtree, and all versions of a product under a product-specific subtree, enabling a management station to determine manufacturer and model even for unknown ProductIDs.
The hrSWRunTable may contain entries for software loaded from network-mounted file systems that will not have corresponding entries in hrSWInstalledTable, since the installed table only covers software stored locally on the host.
If hrFSLastFullBackupDate or hrFSLastPartialBackupDate is not known, the value shall correspond to January 1, year 0000, 00:00:00.0, encoded as (hex)'00 00 01 01 00 00 00 00'.
If hrPartitionFSIndex has no file system mounted, then this value shall be zero; multiple partitions may point to one file system, but multiple file systems may not reside on one partition.
Implementation of the Host Resources Device Group (hrDevice) is mandatory for all host systems.
Implementation of the Host Resources Storage Group (hrStorage) is mandatory for all host systems.
Implementation of the Host Resources System Group (hrSystem) is mandatory for all host systems.
Implementation of the Running Software Group (hrSWRun) and Installed Software Group (hrSWInstalled) is optional.
Implementation of the System and Interfaces groups of MIB-II is mandatory for implementors of the Host Resources MIB.
Setting hrSWRunStatus to invalid(4) shall cause the software to stop running and to be unloaded.
The hrDeviceIndex value for each device must remain constant at least from one re-initialization of the agent to the next re-initialization.
The hrDeviceTable represents all devices on the host with fields hrDeviceIndex, hrDeviceType (OID), hrDeviceDescr (up to 64 chars), hrDeviceID (ProductID), hrDeviceStatus (unknown/running/warning/testing/down), and hrDeviceErrors counter.
The hrNetworkTable is a sparse extension of hrDeviceTable for network devices, containing only hrNetworkIfIndex which links to the corresponding ifIndex in MIB-II.
The hrPrinterTable contains hrPrinterStatus (other/unknown/idle/printing/warmup) and hrPrinterDetectedErrorState (an OCTET STRING bitmask encoding conditions such as lowPaper, noPaper, lowToner, noToner, doorOpen, jammed, offline, and serviceRequested).
The hrProcessorTable is a sparse extension of hrDeviceTable for processor entries, containing hrProcessorFrwID (firmware ProductID) and hrProcessorLoad (0–100 integer representing average CPU utilization over the last minute).
The hrStorageTable is a conceptual table of logical storage areas, indexed by hrStorageIndex, with fields for type (OID), description, allocation unit size in bytes, total size, used size (all in allocation units), and allocation failure counter.
The hrSWInstalledTable lists software stored locally on the host, with fields for index, name, ProductID, type, and hrSWInstalledDate (last-modification date). hrSWInstalledLastChange and hrSWInstalledLastUpdateTime enable efficient polling for table changes.
The hrSWRunPerfTable augments hrSWRunTable with hrSWRunPerfCPU (centi-seconds of CPU consumed) and hrSWRunPerfMem (KBytes of real memory allocated to the process).
The hrSWRunTable contains entries for each running piece of software with fields for index, name, ProductID, path, parameters, type (operatingSystem/deviceDriver/application/unknown), and read-write status (running/runnable/notRunnable/invalid).
The hrSystem group contains seven mandatory objects: hrSystemUptime (TimeTicks since host initialization), hrSystemDate (local date/time, read-write), hrSystemInitialLoadDevice (boot device index), hrSystemInitialLoadParameters (boot parameters), hrSystemNumUsers (active user sessions), hrSystemProcesses (process count), and hrSystemMaxProcesses (maximum process limit).
Device type OIDs registered under hrDeviceTypes (mib-2.25.3.1): processor (.3), network (.4), printer (.5), diskStorage (.6), video (.10), audio (.11), coprocessor (.12), keyboard (.13), modem (.14), parallelPort (.15), pointing (.16), serialPort (.17), tape (.18), clock (.19), volatileMemory (.20), nonVolatileMemory (.21).
File system type OIDs registered under hrFSTypes (mib-2.25.3.9): BerkeleyFFS (.3), Sys5FS (.4), FAT (.5), HPFS (.6), HFS (.7), MFS (.8), NTFS (.9), VNode (.10), Journaled (.11), iso9660 (.12), RockRidge (.13), NFS (.14), Netware (.15), AFS (.16), DFS (.17), Appleshare (.18), RFS (.19), DGCFS (.20), BFS (.21).
Storage type OIDs registered under hrStorageTypes (mib-2.25.2.1): hrStorageOther (.1), hrStorageRam (.2), hrStorageVirtualMemory (.3), hrStorageFixedDisk (.4), hrStorageRemovableDisk (.5), hrStorageFloppyDisk (.6), hrStorageCompactDisc (.7), hrStorageRamDisk (.8).
The RFC explicitly states that security issues are not discussed in this memo, providing no access control guidance for the read-write objects (hrSystemDate, hrSystemInitialLoadDevice, hrSystemInitialLoadParameters, hrStorageSize, hrSWRunStatus, hrFSLastFullBackupDate, hrFSLastPartialBackupDate) that could be exploited to alter host configuration.
hrPrinterDetectedErrorState is an OCTET STRING bitmask where bit 0 (MSB of first byte) = lowPaper, bit 1 = noPaper, bit 2 = lowToner, bit 3 = noToner, bit 4 = doorOpen, bit 5 = jammed, bit 6 = offline, bit 7 = serviceRequested; a set bit indicates the condition is detected.
The DateAndTime textual convention is an OCTET STRING of SIZE 8 or 11: octets 1–2 = year (network byte order, 0..65536), octet 3 = month (1..12), 4 = day, 5 = hour, 6 = minutes, 7 = seconds (0..60 to allow leap second), 8 = deci-seconds; optional octets 9 = UTC direction ('+'/'-' ASCII), 10 = hours from UTC (0..11), 11 = minutes from UTC (0..59).
The KBytes textual convention is an INTEGER (0..2147483647) representing memory size in units of 1024 bytes, used for hrMemorySize, hrStorageSize, hrDiskStorageCapacity, hrPartitionSize, and hrSWRunPerfMem.