OPSAWG H.A. Asai
Internet-Draft Univ. of Tokyo
Intended status: Standards Track M.M. MacFaden
Expires: August 14, 2014 VMware Inc.
J.S. Schoenwaelder
Jacobs University
Y.S. Sekiyanotfirstpage
Univ. of Tokyo
K.S. Shima
IIJ Innovation Institute Inc.
T.T. Tsou
Huawei Technologies (USA)
C.Z. Zhounotfirstpage
Huawei Technologies
H.E. Esakinotfirstpage
Univ. of Tokyo
February 10, 2014

Management Information Base for Virtual Machines Controlled by a Hypervisor
draft-ietf-opsawg-vmm-mib-00

Abstract

This document defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, this specifies objects for managing virtual machines controlled by a hypervisor (a.k.a. virtual machine monitor).

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on August 14, 2014.

Copyright Notice

Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.


Table of Contents

1. Introduction

This document defines a portion of the Management Information Base (MIB) for use with network management protocols in the Internet community. In particular, this specifies objects for managing virtual machines controlled by a hypervisor (a.k.a. virtual machine monitor). A hypervisor controls multiple virtual machines on a single physical machine by allocating resources to each virtual machine using virtualization technologies. Therefore, this MIB module contains information on virtual machines and their resources controlled by a hypervisor as well as hypervisor's hardware and software information.

The design of this MIB module has been derived from enterprise specific MIB modules, namely a MIB module for managing guests of the Xen hypervisor, a MIB module for managing virtual machines controlled by the VMware hypervisor, and a MIB module using the libvirt programming interface to access different hypervisors. However, this MIB module attempts to generalize the managed objects to support other implementations of hypervisors.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].

2. The Internet-Standard Management Framework

For a detailed overview of the documents that describe the current Internet-Standard Management Framework, please refer to section 7 of RFC 3410 [RFC3410]. Managed objects are accessed via a virtual information store, termed the Management Information Base or MIB. MIB objects are generally accessed through the Simple Network Management Protocol (SNMP). Objects in the MIB are defined using the mechanisms defined in the Structure of Management Information (SMI). This memo specifies a MIB module that is compliant to the SMIv2, which is described in STD 58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580 [RFC2580].

3. Overview and Objectives

This document defines a portion of MIB for the management of virtual machines controlled by a hypervisor. This MIB module consists of the managed objects related to system and software information of a hypervisor, the list of virtual machines controlled by the hypervisor, and information of virtual resources allocated by the hypervisor to virtual machines. This document specifies four specific types of virtual resources that are common to many hypervisors; processors (CPUs), memory, network interfaces (NICs), and storage devices. The objects are independent of the hypervisors or operating systems running on virtual machines.

+------------------------------------------------------------------+
| +-------------------------------------------------+              |
| | Virtual machine                                 |              |
| |                                                 |              |
| | +---------+ +---------+ +---------+ +---------+ | .......      |
| | | Virtual | | Virtual | | Virtual | | Virtual | |              |
| +-| CPU     |-| memory  |-| storage |-| NIC     |-+              |
|   +---------+ +---------+ +---------+ +---------+                |
|            Virtual resources                                     |
|                   ^                                              |
|                   | Allocation using virtualization technologies |
|                   |                                              |
|                   +-- Physical resources  ._____.                |
|              +--------+    .--------.    /       \    +--^--+    |
+- - - - - - - |        | - /________/| - *\_______/* - |     | - -+
| Hypervisor   |  CPU   |   | Memory |/   | Storage |   | NIC |    |
|              +--------+   +--------+     \_______/    +-----+    |
|                    +-----------------------+                     |
|                    ||     MIB objects     ||                     |
|                    +-----------------------+                     |
+------------------------------------------------------------------+

A hypervisor allocates virtual resources such as virtual CPUs, virtual memory, virtual storage devices, and virtual network interfaces to virtual machines from physical resources.

Figure 1: An example of a virtualization environment

On the common implementations of hypervisors, a hypervisor allocates virtual resources from physical resources; virtual CPUs, virtual memory, virtual storage devices, and virtual network interfaces to virtual machines as shown in Figure 1. Since the virtual resources allocated to virtual machines are managed by the hypervisor, the MIB objects are managed at a hypervisor. If the objects are accessed through the SNMP, an SNMP agent is launched at the hypervisor to provide access to the objects.

The objects are managed from the viewpoint of the operators of hypervisors, but not the operators of virtual machines; i.e., the objects do not take into account the actual resource utilization on each virtual machine but the resource allocation from the physical resources. For example, vmNetworkIfIndex indicates the virtual interface associated with an interface of a virtual machine at the hypervisor, and consequently, the `in' and `out' directions denote `from a virtual machine to the hypervisor' and `from the hypervisor to a virtual machine', respectively. Moreover, vmStorageAllocatedSize denotes the size allocated by the hypervisor, but not the size actually used by the operating system on the virtual machine. This means that vmStorageDefinedSize and vmStorageAllocatedSize do not take different values when the vmStorageSourceType is `block' or `raw'.

The objectives of this document are the followings: 1) This document defines the MIB objects common to many hypervisors for the management of virtual machines controlled by a hypervisor. 2) This document clarifies the relationship between other MIB modules for managing host computers and network devices.

4. Structure of the VM-MIB Module

The MIB module is organized into a group of scalars and tables. The scalars below `hypervisor' provide basic information about the hypervisor. The `vmTable' lists the virtual machines (guests) that are known to the hypervisor. The `vmCpuTable' provides the mapping table of virtual CPUs to virtual machines, including CPU time used by each virtual CPU. The 'vmCpuAffinityTable' provides the affinity of each virtual CPU to a physical CPU. The `vmStorageTable' provides the list of virtual storage devices and their mapping to virtual machines. In case that an entry in the `vmStorageTable' has a corresponding parent physical storage device managed in `vmStorageTable' of HOST-RESOURCES-MIB [RFC2790], the entry contains a pointer `vmStorageParent' to the physical storage device. The `vmNetworkTable' provides the list of virtual network interfaces and their mapping to virtual machines. Each entry in the `vmNetworkTable' also provides a pointer `vmNetworkIfIndex' to the corresponding entry in the `ifTable' of IF-MIB [RFC2863]. In case that an entry in the `vmNetworkTable' has a corresponding parent physical network interface managed in `ifTable' of IF-MIB, the entry contains a pointer `vmNetworkParent' to the physical network interface.

*: `vmAdminState' write access
!: Notification
+-------------+   + - - - - - - +
| finite      |   | transient   |
| vmOperState |   | vmOperState |
+-------------+   + - - - - - - +

================================================================

+--------------+   + - - - - - - - +     +-------------+
|  suspended   |<--|  suspending   |     |   paused    |
| !vmSuspended |   | !vmSuspending |     |  !vmPaused  |
+--------------+   + - - - - - - - +     +-------------+
      |                ^ *suspended         ^ *paused
      |                |                    |
      v  *running      |         *running   |
+ - - - - - - +   +-------------+<----------+    + - - - - - - -+
|  resuming   |-->|   running   |<-------------->|  migrating   |
| !vmResuming |   |  !vmRunning |                | !vmMigrating |
+ - - - - - - +   +-------------+                + - - - - - - -+
                       |      ^ *running               ^
                       |      |                        |
                       |      +-------------------+    |
                       |                          |    |
                       v *shutdown       *destroy v    v
                + - - - - - - - - +          +-------------+
                |  shuttingdown   |--------->|  shutdown   |
                | !vmShuttingdown |          | !vmShutdown |
                + - - - - - - - - +          +-------------+
                                                 ^      |
                                                 |      v !vmDeleted
+ - - - - - -+   +------------+     + - - - - - - +    (Deleted from
|  blocked   |   |  crashed   |     |  preparing  |     vmTable)
| !vmBlocked |   | !vmCrashed |     |             |
+ - - - - - -+   +------------+     + - - - - - - +

The state transition of a virtual machine

Figure 2: State transition of a virtual machine

The `vmAdminState' and `vmOperState' textual conventions define an administrative state and an operational state model for virtual machines. Events causing transitions between major operational states will cause the generation of notifications. Per virtual machine (per-VM) notifications (vmRunning, vmShutdown, vmPaused, vmSuspended, vmCrashed, vmDeleted) are generated if vmPerVMNotificationsEnabled is true(1). Bulk notifications (vmBulkRunning, vmBulkShutdown, vmBulkPaused, vmBulkSuspended, vmBulkCrashed, vmBulkDeleted) are generated if vmBulkNotificationsEnabled is true(1). The transition of `vmOperState' by the write access to `vmAdminState' and the notifications generated by the operational state changes are summarized in Figure 2. Note that the notifications shown in this figure are per-VM notifications. In the case of Bulk notifications, the prefix `vm' is replaced with 'vmBulk'.

The bulk notification mechanism is designed to reduce the number of notifications that are trapped by an SNMP manager. This is because the number of virtual machines managed by a bunch of hypervisors in a datacenter possibly becomes several thousands or more, and consequently, many notifications could be trapped if these virtual machines frequently change their administrative state. The per-VM notifications carry more detailed information, but the scalability shall be a problem. An implementation shall support both, either of, or none of per-VM notifications and bulk notifications. The notification filtering mechanism described in section 6 of RFC 3413 [RFC3413] is used by the management applications to control the notifications.

The MIB module provides a few writable objects that can be used to make non-persistent changes, e.g., changing the memory allocation or the CPU allocation. It is not the goal of this MIB module to provide a configuration interface for virtual machines since other protocols and data modeling languages are more suitable for this task.

The OID tree structure of the MIB module is shown below.

--vmMIB (1.3.6.1.2.1.yyy)
  +--vmNotifications(0)
  |  +--vmRunning(1) [vmName, vmUUID, vmOperState]
  |  +--vmShuttingdown(2) [vmName, vmUUID, vmOperState]
  |  +--vmShutdown(3) [vmName, vmUUID, vmOperState]
  |  +--vmPaused(4) [vmName, vmUUID, vmOperState]
  |  +--vmSuspending(5) [vmName, vmUUID, vmOperState]
  |  +--vmSuspended(6) [vmName, vmUUID, vmOperState]
  |  +--vmResuming(7) [vmName, vmUUID, vmOperState]
  |  +--vmMigrating(8) [vmName, vmUUID, vmOperState]
  |  +--vmCrashed(9) [vmName, vmUUID, vmOperState]
  |  +--vmBlocked(10) [vmName, vmUUID, vmOperState]
  |  +--vmDeleted(11) [vmName, vmUUID, vmOperState, vmPersistent]
  |  +--vmBulkRunning(12) [vmAffectedVMs]
  |  +--vmBulkShutdown(13) [vmAffectedVMs]
  |  +--vmBulkShuttingdown(14) [vmAffectedVMs]
  |  +--vmBulkPaused(15) [vmAffectedVMs]
  |  +--vmBulkSuspending(16) [vmAffectedVMs]
  |  +--vmBulkSuspended(17) [vmAffectedVMs]
  |  +--vmBulkResuming(18) [vmName, vmUUID, vmOperState]
  |  +--vmBulkMigrating(19) [vmAffectedVMs]
  |  +--vmBulkCrashed(20) [vmAffectedVMs]
  |  +--vmBulkBlocked(21) [vmAffectedVMs]
  |  +--vmBulkDeleted(22) [vmAffectedVMs]
  +--vmObjects(1)
  |  +--vmHypervisor(1)
  |  |  +-- r-n SnmpAdminString    vmHvSoftware(1)
  |  |  +-- r-n SnmpAdminString    vmHvVersion(2)
  |  |  +-- r-n OBJECT IDENTIFIER  vmHvObjectID(3)
  |  |  +-- r-n TimeTicks          vmHvUpTime(4)
  |  +-- r-n Integer32  vmNumber(2)
  |  +-- r-n TimeTicks  vmTableLastChange(3)
  |  +--vmTable(4)
  |  |  +--vmEntry(1) [vmIndex]
  |  |     +-- --- VirtualMachineIndex  vmIndex(1)
  |  |     +-- r-n SnmpAdminString      vmName(2)
  |  |     +-- r-n UUIDorZero           vmUUID(3)
  |  |     +-- r-n SnmpAdminString      vmOSType(4)
  |  |     +-- rwn VirtualMachineAdminState
  |  |     |                            vmAdminState(5)
  |  |     +-- r-n VirtualMachineOperState
  |  |     |                            vmOperState(6)
  |  |     +-- r-n VirtualMachineAutoStart
  |  |     |                            vmAutoStart(7)
  |  |     +-- r-n VirtualMachinePersistent
  |  |     |                            vmPersistent(8)
  |  |     +-- rwn Integer32            vmCurCpuNumber(9)
  |  |     +-- rwn Integer32            vmMinCpuNumber(10)
  |  |     +-- rwn Integer32            vmMaxCpuNumber(11)
  |  |     +-- r-n Integer32            vmMemUnit(12)
  |  |     +-- rwn Integer32            vmCurMem(13)
  |  |     +-- rwn Integer32            vmMinMem(14)
  |  |     +-- rwn Integer32            vmMaxMem(15)
  |  |     +-- r-n TimeTicks            vmUpTime(16)
  |  |     +-- r-n Counter64            vmCpuTime(17)
  |  +--vmCpuTable(5)
  |  |  +--vmCpuEntry(1) [vmIndex, vmCpuIndex]
  |  |     +-- --- VirtualMachineCpuIndex
  |  |     |                            vmCpuIndex(1)
  |  |     +-- r-n Counter64            vmCpuCoreTime(2)
  |  +--vmCpuAffinityTable(6)
  |  |  +--vmCpuAffinityEntry(1) [vmIndex,
  |  |     |                      vmCpuIndex,
  |  |     |                      vmCpuPhysIndex]
  |  |     +-- --- Integer32            vmCpuPhysIndex(1)
  |  |     +-- rwn Integer32            vmCpuAffinity(2)
  |  +--vmStorageTable(7)
  |  |  +--vmStorageEntry(1) [vmStorageVmIndex, vmStorageIndex]
  |  |     +-- --- VirtualMachineIndexOrZero
  |  |     |                            vmStorageVmIndex(1)
  |  |     +-- --- VirtualMachineStorageIndex
  |  |     |                            vmStorageIndex(2)
  |  |     +-- r-n Integer32            vmStorageParent(3)
  |  |     +-- r-n VirtualMachineStorageSourceType
  |  |     |                            vmStorageSourceType(4)
  |  |     +-- r-n SnmpAdminString      vmStorageSourceTypeString(5)
  |  |     +-- r-n SnmpAdminString      vmStorageResourceID(6)
  |  |     +-- r-n VirtualMachineStorageAccess
  |  |     |                            vmStorageAccess(7)
  |  |     +-- r-n VirtualMachineStorageMediaType
  |  |     |                            vmStorageMediaType(8)
  |  |     +-- r-n SnmpAdminString      vmStorageMediaTypeString(9)
  |  |     +-- r-n Integer32            vmStorageSizeUnit(10)
  |  |     +-- r-n Integer32            vmStorageDefinedSize(11)
  |  |     +-- r-n Integer32            vmStorageAllocatedSize(12)
  |  |     +-- r-n Counter64            vmStorageReadIOs(13)
  |  |     +-- r-n Counter64            vmStorageWriteIOs(14)
  |  +--vmNetworkTable(8)
  |  |  +--vmNetworkEntry(1) [vmIndex, vmNetworkIndex]
  |  |     +-- --- VirtualMachineNetworkIndex
  |  |     |                            vmNetworkIndex(1)
  |  |     +-- r-n InterfaceIndexOrZero vmNetworkIfIndex(2)
  |  |     +-- r-n InterfaceIndexOrZero vmNetworkParent(3)
  |  |     +-- r-n SnmpAdminString      vmNetworkModel(4)
  |  |     +-- r-n PhysAddress          vmNetworkPhysAddress(5)
  |  +-- rwn TruthValue           vmPerVMNotificationsEnabled(9)
  |  +-- rwn TruthValue           vmBulkNotificationsEnabled(10)
  |  +-- --n VirtualMachineList   vmAffectedVMs(11)
  +--vmConformance(2)
     +--vmCompliances(1)
     |  +--vmFullCompliances(1)
     |  +--vmReadOnlyCompliances(2)
     +--vmGroups(2)
        +--vmHypervisorGroup(1)
        +--vmVirtualMachineGroup(2)
        +--vmCpuGroup(3)
        +--vmCpuAffinityGroup(4)
        +--vmStorageGroup(5)
        +--vmNetworkGroup(6)
        +--vmPerVMNotificationOptionalGroup(7)
        +--vmBulkNotificationsVariablesGroup(8)
        +--vmBulkNotificationOptionalGroup(9)
        

5. Relationship to Other MIB Modules

HOST-RESOURCES-MIB [RFC2790] defines the MIB objects for managing host systems. Hypervisors shall implement HOST-RESOURCES-MIB. On systems implementing HOST-RESOURCES-MIB, the objects of HOST-RESOURCES-MIB indicate resources of a hypervisor. Some objects of HOST-RESOURCES-MIB shall also be used to indicate physical resources through indexes. On systems implementing HOST-RESOURCES-MIB, the `vmCpuPhysIndex' points to the processor's `hrDeviceIndex' in the `hrProcessorTable'. The `vmStorageParent' also points to the storage device's `hrStorageIndex' in the `hrStorageTable'.

HOST-RESOURCES-MIB shall be implemented on systems running on virtual machines. It enables to manage the objects related to the resources of virtual machines from the viewpoint of virtual machine operators. However, from the viewpoint of hypervisor operators, it cannot obtain the list of virtual machines controlled by a hypervisor and the relationship between physical and virtual resources. This document defines the objects of these information.

IF-MIB [RFC2863] defines the MIB objects for managing network interfaces. Both physical and virtual network interfaces are required to be contained in the `ifTable' of IF-MIB. The virtual network interfaces in the `ifTable' of IF-MIB are pointed from the `vmNetworkTable' defined in this document through a pointer `vmNetworkIfIndex'. In case that an entry in the `vmNetworkTable' has a corresponding parent physical network interface managed in the `ifTable' of IF-MIB, the entry contains a pointer `vmNetworkParent' to the physical network interface.

The objects related to virtual switches are not also included in the MIB module defined in this document though virtual switches shall be placed on a hypervisor. This is because the virtual network interfaces are the lowest abstraction of network resources allocated to a virtual machine. Instead of including the objects related to virtual switches, for example, IEEE8021-BRIDGE-MIB and IEEE8021-Q-BRIDGE-MIB could be used.

The other objects related to virtual machines such as management IP addresses of a virtual machine are not included in this MIB module because this MIB module defines the objects common to general hypervisors but they are specific to some hypervisors. They may be included in the entLogicalTable of ENTITY-MIB [RFC6933].

6. Definitions

VM-MIB DEFINITIONS ::= BEGIN

IMPORTS
    MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE, TimeTicks,
    Counter64, Integer32, mib-2
        FROM SNMPv2-SMI
    OBJECT-GROUP, MODULE-COMPLIANCE, NOTIFICATION-GROUP
        FROM SNMPv2-CONF
    TEXTUAL-CONVENTION, PhysAddress, TruthValue
        FROM SNMPv2-TC
    SnmpAdminString
        FROM SNMP-FRAMEWORK-MIB
    UUIDorZero
        FROM UUID-TC-MIB
    InterfaceIndexOrZero
        FROM IF-MIB;

vmMIB MODULE-IDENTITY
    LAST-UPDATED "201402080000Z"        -- 8 February 2014
    ORGANIZATION "IETF Operations and Management Area Working Group"
    CONTACT-INFO
            "
            WG E-mail: opsawg@ietf.org
            Mailing list subscription info:
              https://www.ietf.org/mailman/listinfo/opsawg

            Hirochika Asai
            The University of Tokyo
            7-3-1 Hongo
            Bunkyo-ku, Tokyo  113-8656
            JP
            Phone: +81 3 5841 6748
            Email: panda@hongo.wide.ad.jp

            Michael MacFaden
            VMware Inc.
            Email: mrm@vmware.com

            Juergen Schoenwaelder
            Jacobs University
            Campus Ring 1
            Bremen 28759
            Germany
            Email: j.schoenwaelder@jacobs-university.de

            Keiichi Shima
            IIJ Innovation Institute Inc.
            3-13 Kanda-Nishikicho
            Chiyoda-ku, Tokyo  101-0054
            JP
            Email: keiichi@iijlab.net

            Tina Tsou
            Huawei Technologies (USA)
            2330 Central Expressway
            Santa Clara  CA 95050
            USA
            Email: tina.tsou.zouting@huawei.com
            "

    DESCRIPTION
            "This MIB module is for use in managing a hypervisor and
            virtual machines controlled by the hypervisor.  The OID
            `yyy' is temporary one, and it must be assigned by IANA
            when this becomes an official document.

            Copyright (c) 2014 IETF Trust and the persons identified
            as authors of the code.  All rights reserved.

            Redistribution and use in source and binary forms, with
            or without modification, is permitted pursuant to, and
            subject to the license terms contained in, the
            Simplified BSD License set forth in Section 4.c of the
            IETF Trust's Legal Provisions Relating to IETF Documents
            (http://trustee.ietf.org/license-info)."

    REVISION "201402080000Z"        -- 8 February 2014
    DESCRIPTION
            "The original version of this MIB, published as
            RFCXXXX."
    ::= { mib-2 yyy }


vmNotifications OBJECT IDENTIFIER ::= { vmMIB 0 }
vmObjects       OBJECT IDENTIFIER ::= { vmMIB 1 }
vmConformance   OBJECT IDENTIFIER ::= { vmMIB 2 }


-- Textual conversion definitions
--
VirtualMachineIndex ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "d"
    STATUS       current
    DESCRIPTION
            "A unique value, greater than zero, identifying a
            virtual machine.  The value for each virtual machine
            must remain constant at least from one re-initialization
            of the hypervisor to the next re-initialization."
    SYNTAX       Integer32 (1..2147483647)

VirtualMachineIndexOrZero ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "d"
    STATUS       current
    DESCRIPTION
            "This textual convention is an extension of the
            VirtualMachineIndex convention.  This extension permits
            the additional value of zero.  The meaning of the value
            zero is object-specific and must therefore be defined as
            part of the description of any object which uses this
            syntax.  Examples of the usage of zero might include
            situations where a virtual machine is unknown, or when
            none or all virtual machines need to be referenced."
    SYNTAX       Integer32 (0..2147483647)

VirtualMachineAdminState ::= TEXTUAL-CONVENTION
    STATUS      current
    DESCRIPTION
            "The administrative state of a virtual machine:

            running(1)    The administrative state of the virtual
                          machine indicating the virtual machine
                          is currently online or should be brought
                          online.

            suspended(2)  The administrative state of the virtual
                          machine where its memory and CPU execution
                          state has been saved to persistent store
                          and will be restored at next running(1).

            paused(3)     The administrative state indicating the
                          virtual machine is resident in memory but
                          is no longer scheduled to execute by the
                          hypervisor.

            shutdown(4)   The administrative state of the virtual
                          machine indicating the virtual machine
                          is currently offline or should be taken
                          shutting down.

            destroy(5)    The administrative state of the virtual
                          machine indicating the virtual machine
                          should be forcibly shutdown.  After the
                          destroy operation, the administrative
                          state should be automatically changed to
                          shutdown(4)."
    SYNTAX       INTEGER {
                    running(1),
                    suspended(2),
                    paused(3),
                    shutdown(4),
                    destroy(5)
                 }

VirtualMachineOperState ::= TEXTUAL-CONVENTION
    STATUS       current
    DESCRIPTION
            "The operational state of a virtual machine:

            unknown(1)     The operational state of the virtual
                           machine is unknown, e.g., because the
                           implementation failed to obtain the state
                           from the hypervisor.

            other(2)       The operational state of the virtual
                           machine indicating that an operational
                           state is obtained from the hypervisor but
                           it is not a state defined in this MIB
                           module.

            preparing(3)   The operational state of the virtual
                           machine indicating the virtual machine is
                           currently in the process of preparation,
                           e.g., allocating and initializing virtual
                           storage after creating (defining) virtual
                           machine.

            running(4)     The operational state of the virtual
                           machine indicating the virtual machine is
                           currently executed but it is not in the
                           process of preparing(3), suspending(6),
                           resuming(8), migrating(10), and
                           shuttingdown(11).

            blocked(5)     The operational state of the virtual
                           machine indicating the execution of the
                           virtual machine is currently blocked,
                           e.g., waiting for some action of the
                           hypervisor to finish.  This is a
                           transient state from/to other states.

            suspending(6)  The operational state of the virtual
                           machine indicating the virtual machine is
                           currently in the process of suspending
                           to save its memory and CPU execution
                           state to persistent store.  This is a
                           transient state from running(4) to
                           suspended(7).

            suspended(7)   The operational state of the virtual
                           machine indicating the virtual machine is
                           currently suspended, which means the
                           memory and CPU execution state of the
                           virtual machine are saved to persistent
                           store.  During this state, the virtual
                           machine is not scheduled to execute by
                           the hypervisor.

            resuming(8)    The operational state of the virtual
                           machine indicating the virtual machine is
                           currently in the process of resuming
                           to restore its memory and CPU execution
                           state from persistent store.  This is a
                           transient state from suspended(7) to
                           running(4).

            paused(9)      The operational state of the virtual
                           machine indicating the virtual machine is
                           resident in memory but no longer
                           scheduled to execute by the hypervisor.

            migrating(10)  The operational state of the virtual
                           machine indicating the virtual machine is
                           currently in the process of migration
                           from/to another hypervisor.

            shuttingdown(11)
                           The operational state of the virtual
                           machine indicating the virtual machine is
                           currently in the process of shutting
                           down.  This is a transient state from
                           running(4) to shutdown(12).

            shutdown(12)   The operational state of the virtual
                           machine indicating the virtual machine is
                           down, and CPU execution is no longer
                           scheduled by the hypervisor and its
                           memory is not resident in the hypervisor.

            crashed(13)    The operational state of the virtual
                           machine indicating the virtual machine
                           has crashed."
    SYNTAX       INTEGER {
                    unknown(1),
                    other(2),
                    preparing(3),
                    running(4),
                    blocked(5),
                    suspending(6),
                    suspended(7),
                    resuming(8),
                    paused(9),
                    migrating(10),
                    shuttingdown(11),
                    shutdown(12),
                    crashed(13)
                 }

VirtualMachineAutoStart ::= TEXTUAL-CONVENTION
    STATUS       current
    DESCRIPTION
            "The autostart configuration of a virtual machine:

            unknown(1)     The autostart configuration is unknown,
                           e.g., because the implementation failed
                           to obtain the autostart configuration
                           from the hypervisor.

            enabled(2)     The autostart configuration of the
                           virtual machine is enabled.  The virtual
                           machine should be automatically brought
                           online at the next re-initialization of
                           the hypervisor.

            disabled(3)    The autostart configuration of the
                           virtual machine is disabled.  The virtual
                           machine should not be automatically
                           brought online at the next
                           re-initialization of the hypervisor."
    SYNTAX      INTEGER {
                    unknown(1),
                    enabled(2),
                    disabled(3)
                }

VirtualMachinePersistent ::= TEXTUAL-CONVENTION
    STATUS       current
    DESCRIPTION
            "This value indicates whether a virtual machine has a
            persistent configuration which means the virtual machine
            will still exist after shutting down:

            unknown(1)     The persistent configuration is unknown,
                           e.g., because the implementation failed
                           to obtain the persistent configuration
                           from the hypervisor. (read-only)

            persistent(2)  The virtual machine is persistent, i.e.,
                           the virtual machine will exist after its
                           shutting down.

            transient(3)   The virtual machine is transient, i.e.,
                           the virtual machine will not exist after
                           its shutting down."
    SYNTAX       INTEGER {
                    unknown(1),
                    persistent(2),
                    transient(3)
                 }

VirtualMachineCpuIndex ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "d"
    STATUS       current
    DESCRIPTION
            "A unique value for each virtual machine, greater than
            zero, identifying a virtual CPU assigned to a virtual
            machine.  The value for each virtual CPU must remain
            constant at least from one re-initialization of the
            hypervisor to the next re-initialization."
     SYNTAX      Integer32 (1..2147483647)

VirtualMachineStorageIndex ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "d"
    STATUS       current
    DESCRIPTION
            "A unique value for each virtual machine, greater than
            zero, identifying a virtual storage device allocated to
            a virtual machine.  The value for each virtual storage
            device must remain constant at least from one
            re-initialization of the hypervisor to the next
            re-initialization."
     SYNTAX      Integer32 (1..2147483647)

VirtualMachineStorageSourceType ::= TEXTUAL-CONVENTION
    STATUS       current
    DESCRIPTION
            "The source type of a virtual storage device:

            unknown(1)     The source type is unknown, e.g., because
                           the implementation failed to obtain the
                           media type from the hypervisor.

            other(2)       The source type is other than those
                           defined in this conversion.

            block(3)       The source type is a block device.

            raw(4)         The source type is a raw-formatted file.

            sparse(5)      The source type is a sparse file.

            network(6)     The source type is a network device."
    SYNTAX       INTEGER {
                    unknown(1),
                    other(2),
                    block(3),
                    raw(4),
                    sparse(5),
                    network(6)
                 }

VirtualMachineStorageAccess ::= TEXTUAL-CONVENTION
    STATUS       current
    DESCRIPTION
            "The access permission of a virtual storage:

            readwrite(1)   The virtual storage is a read-write
                           device.

            readonly(2)    The virtual storage is a read-only
                           device."
    SYNTAX       INTEGER {
                    readwrite(1),
                    readonly(2)
                 }

VirtualMachineStorageMediaType ::= TEXTUAL-CONVENTION
    STATUS       current
    DESCRIPTION
            "The media type of a virtual storage device:

            unknown(1)     The media type is unknown, e.g., because
                           the implementation failed to obtain the
                           media type from the hypervisor.

            other(2)       The media type is other than those
                           defined in this conversion.

            hardDisk(3)    The media type is hard disk.

            opticalDisk(4) The media type is optical disk."
    SYNTAX       INTEGER {
                    other(1),
                    unknown(2),
                    hardDisk(3),
                    opticalDisk(4)
                 }

VirtualMachineNetworkIndex ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "d"
    STATUS       current
    DESCRIPTION
            "A unique value for each virtual machine, greater than
            zero, identifying a virtual network interface allocated
            to the virtual machine.  The value for each virtual
            network interface must remain constant at least from one
            re-initialization of the hypervisor to the next
            re-initialization."
     SYNTAX      Integer32 (1..2147483647)

VirtualMachineList ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "1x"
    STATUS       current
    DESCRIPTION
            "Each octet within this value specifies a set of eight
            virtual machine vmIndex, with the first octet specifying
            virtual machine 1 through 8, the second octet specifying
            virtual machine 9 through 16, etc.  Within each octet,
            the most significant bit represents the lowest numbered
            vmIndex, and the least significant bit represents the
            highest numbered vmIndex.  Thus, each virtual machine of
            the host is represented by a single bit within the value
            of this object.  If that bit has a value of '1', then
            that virtual machine is included in the set of virtual
            machines; the virtual machine is not included if its bit
            has a value of '0'."
    SYNTAX      OCTET STRING

-- The hypervisor group
--
-- A collection of objects common to all hypervisors.
--
vmHypervisor    OBJECT IDENTIFIER ::= { vmObjects 1 }

vmHvSoftware OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A textual description of the hypervisor software.  This
            value should not include its version, and it should be
            included in `vmHvVersion'."
    ::= { vmHypervisor 1 }

vmHvVersion OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A textual description of the version of the hypervisor
            software."
    ::= { vmHypervisor 2 }

vmHvObjectID OBJECT-TYPE
    SYNTAX       OBJECT IDENTIFIER
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The vendor's authoritative identification of the
            hypervisor software contained in the entity.  This value
            is allocated within the SMI enterprises
            subtree (1.3.6.1.4.1).  Note that this is different from
            sysObjectID in the SNMPv2-MIB [RFC3418] because
            sysObjectID is not the identification of the hypervisor
            software but the device, firmware, or management
            operating system."
    ::= { vmHypervisor 3 }

vmHvUpTime OBJECT-TYPE
    SYNTAX       TimeTicks
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The time (in centi-seconds) since the hypervisor was
            last re-initialized.  Note that this is different from
            sysUpTime in the SNMPv2-MIB [RFC3418] and hrSystemUptime
            in the HOST-RESOURCES-MIB [RFC2790] because sysUpTime is
            the uptime of the network management portion of the
            system, and hrSystemUptime is the uptime of the
            management operating system but not the hypervisor
            software."
    ::= { vmHypervisor 4 }


-- The virtual machine information
--
-- A collection of objects common to all virtual machines.
--
vmNumber  OBJECT-TYPE
    SYNTAX       Integer32 (0..2147483647)
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The number of virtual machines (regardless of their
            current state) present on this hypervisor."
    ::= { vmObjects 2 }

vmTableLastChange  OBJECT-TYPE
    SYNTAX       TimeTicks
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The value of vmHvUpTime at the time of the last creation
            or deletion of an entry in the vmTable."
    ::= { vmObjects 3 }

vmTable OBJECT-TYPE
    SYNTAX       SEQUENCE OF VmEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "A list of virtual machine entries.  The number of
            entries is given by the value of vmNumber."
    ::= { vmObjects 4 }

vmEntry OBJECT-TYPE
    SYNTAX       VmEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "An entry containing management information applicable
            to a particular virtual machine."
    INDEX   { vmIndex }
    ::= { vmTable 1 }

VmEntry ::=
    SEQUENCE {
        vmIndex                 VirtualMachineIndex,
        vmName                  SnmpAdminString,
        vmUUID                  UUIDorZero,
        vmOSType                SnmpAdminString,
        vmAdminState            VirtualMachineAdminState,
        vmOperState             VirtualMachineOperState,
        vmAutoStart             VirtualMachineAutoStart,
        vmPersistent            VirtualMachinePersistent,
        vmCurCpuNumber          Integer32,
        vmMinCpuNumber          Integer32,
        vmMaxCpuNumber          Integer32,
        vmMemUnit               Integer32,
        vmCurMem                Integer32,
        vmMinMem                Integer32,
        vmMaxMem                Integer32,
        vmUpTime                TimeTicks,
        vmCpuTime               Counter64
    }

vmIndex OBJECT-TYPE
    SYNTAX       VirtualMachineIndex
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "A unique value, greater than zero, identifying the
            virtual machine. The value assigned to a given virtual
            machine may not persist across re-initialization of the
            hypervisor.  A command generator must use the vmUUID to
            identify a given virtual machine of interest."
    ::= { vmEntry 1 }

vmName OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A textual name of the virtual machine."
    ::= { vmEntry 2 }

vmUUID OBJECT-TYPE
    SYNTAX       UUIDorZero
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The virtual machine's 128-bit UUID or the zero-length
            string when a UUID is not available.  The UUID if set
            must uniquely identify a virtual machine from all other
            virtual machines in an administrative region.  A
            zero-length octet string is returned if no UUID
            information is known."
    ::= { vmEntry 3 }

vmOSType OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A textual description containing operating system
            information installed on the virtual machine.  This
            value corresponds to the operating system the hypervisor
            assumes to be running when the virtual machine is
            started.  This may differ from the actual operating
            system in case the virtual machine boots into a
            different operating system."
    ::= { vmEntry 4 }

vmAdminState OBJECT-TYPE
    SYNTAX       VirtualMachineAdminState
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The administrative power state of the virtual machine.
            Note that a virtual machine is supposed to be resumed
            when vmAdminState of the virtual machine is changed from
            suspended(2) or paused(3) to running(1)."
    ::= { vmEntry 5 }

vmOperState OBJECT-TYPE
    SYNTAX       VirtualMachineOperState
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The operational state of the virtual machine."
    ::= { vmEntry 6 }

vmAutoStart OBJECT-TYPE
    SYNTAX       VirtualMachineAutoStart
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The autostart configuration of the virtual machine.  If
            this value is enable(2), the virtual machine
            automatically starts at the next initialization of the
            hypervisor."
    ::= { vmEntry 7 }

vmPersistent OBJECT-TYPE
    SYNTAX       VirtualMachinePersistent
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "This value indicates whether the virtual machine has a
            persistent configuration which means the virtual machine
            will still exist after its shutdown."
    ::= { vmEntry 8 }

vmCurCpuNumber OBJECT-TYPE
    SYNTAX       Integer32 (0..2147483647)
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The number of virtual CPUs currently assigned to the
            virtual machine.  Changes to this object MUST NOT
            persist across re-initialization of the hypervisor."
    ::= { vmEntry 9 }

vmMinCpuNumber OBJECT-TYPE
    SYNTAX       Integer32 (-1|0..2147483647)
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The minimum number of virtual CPUs that are assigned to
            the virtual machine when it is in a power-on state.  The
            value -1 indicates that there is no hard boundary for
            the minimum number of virtual CPUs.  Changes to this
            object MUST NOT persist across re-initialization of the
            hypervisor."
    ::= { vmEntry 10 }

vmMaxCpuNumber OBJECT-TYPE
    SYNTAX       Integer32 (-1|0..2147483647)
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The maximum number of virtual CPUs that are assigned to
            the virtual machine when it is in a power-on state.  The
            value -1 indicates that there is no limit.  Changes to
            this object MUST NOT persist across re-initialization of
            the hypervisor."
    ::= { vmEntry 11 }

vmMemUnit OBJECT-TYPE
    SYNTAX       Integer32 (1..2147483647)
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The multiplication unit for vmCurMem, vmMinMem, and
            vmMaxMem.  For example, when this value is 1024, the
            memory size unit for vmCurMem, vmMinMem, and vmMaxMem is
            KiB."
    ::= { vmEntry 12 }

vmCurMem OBJECT-TYPE
    SYNTAX       Integer32 (0..2147483647)
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The current memory size currently allocated to the
            virtual memory module in the unit designated by
            vmMemUnit.  Changes to this object MUST NOT persist
            across re-initialization of the hypervisor."
    ::= { vmEntry 13 }

vmMinMem OBJECT-TYPE
    SYNTAX       Integer32 (-1|0..2147483647)
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The minimum memory size defined to the virtual machine
            in the unit designated by vmMemUnit.  The value -1
            indicates that there is no hard boundary for the minimum
            memory size.  Changes to this object MUST NOT persist
            across re-initialization of the hypervisor."
    ::= { vmEntry 14 }

vmMaxMem OBJECT-TYPE
    SYNTAX       Integer32 (-1|0..2147483647)
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The maximum memory size defined to the virtual machine
            in the unit designated by vmMemUnit.  The value -1
            indicates that there is no limit.  Changes to this
            object MUST NOT persist across re-initialization of the
            hypervisor."
    ::= { vmEntry 15 }


vmUpTime OBJECT-TYPE
    SYNTAX       TimeTicks
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The time (in centi-seconds) since the administrative
            state of the virtual machine was last changed from
            shutdown(4) to running(1)."
    ::= { vmEntry 16 }

vmCpuTime OBJECT-TYPE
    SYNTAX       Counter64
    UNITS        "microsecond"
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The total CPU time used in microsecond.  If the number
            of virtual CPUs is larger than 1, vmCpuTime may exceed
            real time.

            Discontinuities in the value of this counter can occur
            at re-initialization of the hypervisor, and
            administrative state (vmAdminState) changes of the
            virtual machine."
    ::= { vmEntry 17 }

-- The virtual CPU on each virtual machines
vmCpuTable OBJECT-TYPE
    SYNTAX       SEQUENCE OF VmCpuEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "The table of virtual CPUs provided by the hypervisor."
    ::= { vmObjects 5 }

vmCpuEntry OBJECT-TYPE
    SYNTAX       VmCpuEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "An entry for one virtual processor assigned to a
            virtual machine."
    INDEX { vmIndex, vmCpuIndex }
    ::= { vmCpuTable 1 }

VmCpuEntry ::=
    SEQUENCE {
        vmCpuIndex              VirtualMachineCpuIndex,
        vmCpuCoreTime           Counter64
    }

vmCpuIndex OBJECT-TYPE
    SYNTAX       VirtualMachineCpuIndex
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "A unique value identifying a virtual CPU assigned to
            the virtual machine."
    ::= { vmCpuEntry 1 }

vmCpuCoreTime OBJECT-TYPE
    SYNTAX       Counter64
    UNITS        "microsecond"
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The total CPU time used by this virtual CPU in
            microsecond.

            Discontinuities in the value of this counter can occur
            at re-initialization of the hypervisor, and
            administrative state (vmAdminState) changes of the
            virtual machine."
    ::= { vmCpuEntry 2 }

-- The virtual CPU affinity on each virtual machines
vmCpuAffinityTable OBJECT-TYPE
    SYNTAX       SEQUENCE OF VmCpuAffinityEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "A list of CPU affinity entries of a virtual CPU."
    ::= { vmObjects 6 }

vmCpuAffinityEntry OBJECT-TYPE
    SYNTAX       VmCpuAffinityEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "An entry containing CPU affinity associated with a
            particular virtual machine."
    INDEX   { vmIndex, vmCpuIndex, vmCpuPhysIndex }
    ::= { vmCpuAffinityTable 1 }

VmCpuAffinityEntry ::=
    SEQUENCE {
        vmCpuPhysIndex          Integer32,
        vmCpuAffinity           Integer32
    }

vmCpuPhysIndex OBJECT-TYPE
    SYNTAX       Integer32 (1..2147483647)
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "A value identifying a physical CPU on the hypervisor.
            On systems implementing the HOST-RESOURCES-MIB, the
            value must be the same value that is used as the index
            in the hrProcessorTable (hrDeviceIndex)."
    ::= { vmCpuAffinityEntry 2 }

vmCpuAffinity OBJECT-TYPE
    SYNTAX       INTEGER {
                    unknown(0),   -- unknown
                    enable(1),    -- enabled
                    disable(2)    -- disabled
                 }
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "The CPU affinity of this virtual CPU to the physical
            CPU represented by `vmCpuPhysIndex'."
    ::= { vmCpuAffinityEntry 3 }


-- The virtual storage devices on each virtual machine.  This
-- document defines some overlapped objects with hrStorage in
-- HOST-RESOURCES-MIB [RFC2790], because virtual resources shall be
-- allocated from the hypervisor's resources, which is the `host
-- resources'
vmStorageTable OBJECT-TYPE
    SYNTAX       SEQUENCE OF VmStorageEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "The conceptual table of virtual storage devices
            attached to the virtual machine."
    ::= { vmObjects 7 }

vmStorageEntry OBJECT-TYPE
    SYNTAX       VmStorageEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "An entry for one virtual storage device attached to the
            virtual machine."
    INDEX { vmStorageVmIndex, vmStorageIndex }
    ::= { vmStorageTable 1 }

VmStorageEntry ::=
    SEQUENCE {
        vmStorageVmIndex        VirtualMachineIndexOrZero,
        vmStorageIndex          VirtualMachineStorageIndex,
        vmStorageParent         Integer32,
        vmStorageSourceType     VirtualMachineStorageSourceType,
        vmStorageSourceTypeString
                                SnmpAdminString,
        vmStorageResourceID     SnmpAdminString,
        vmStorageAccess         VirtualMachineStorageAccess,
        vmStorageMediaType      VirtualMachineStorageMediaType,
        vmStorageMediaTypeString
                                SnmpAdminString,
        vmStorageSizeUnit       Integer32,
        vmStorageDefinedSize    Integer32,
        vmStorageAllocatedSize  Integer32,
        vmStorageReadIOs        Counter64,
        vmStorageWriteIOs       Counter64
    }

vmStorageVmIndex OBJECT-TYPE
    SYNTAX       VirtualMachineIndexOrZero
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "This value identifies the virtual machine (guest) this
            storage device has been allocated to.  The value zero
            indicates that the storage device is currently not
            allocated to any virtual machines."
    ::= { vmStorageEntry 1 }

vmStorageIndex OBJECT-TYPE
    SYNTAX       VirtualMachineStorageIndex
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "A unique value identifying a virtual storage device
            allocated to the virtual machine."
    ::= { vmStorageEntry 2 }

vmStorageParent OBJECT-TYPE
    SYNTAX       Integer32 (0..2147483647)
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The value of hrStorageIndex which is the parent (i.e.,
            physical) device of this virtual device on systems
            implementing the HOST-RESOURCES-MIB.  The value zero
            denotes this virtual device is not any child represented
            in the hrStorageTable."
    ::= { vmStorageEntry 3 }

vmStorageSourceType OBJECT-TYPE
    SYNTAX       VirtualMachineStorageSourceType
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The source type of the virtual storage device."
    ::= { vmStorageEntry 4 }

vmStorageSourceTypeString OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A (detailed) textual string of the source type of the
            virtual storage device.  For example, this represents
            the specific format name of the sparse file."
    ::= { vmStorageEntry 5 }

vmStorageResourceID OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A textual string that represents the resource
            identifier of the virtual storage.  For example, this
            contains the path to the disk image file that
            corresponds to the virtual storage."
    ::= { vmStorageEntry 6 }

vmStorageAccess OBJECT-TYPE
    SYNTAX       VirtualMachineStorageAccess
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The access permission of the virtual storage device."
    ::= { vmStorageEntry 7 }

vmStorageMediaType OBJECT-TYPE
    SYNTAX       VirtualMachineStorageMediaType
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The media type of the virtual storage device."
    ::= { vmStorageEntry 8 }

vmStorageMediaTypeString OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A (detailed) textual string of the virtual storage
            media.  For example, this represents the specific driver
            name of the emulated media such as `IDE' and `SCSI'."
    ::= { vmStorageEntry 9 }

vmStorageSizeUnit OBJECT-TYPE
    SYNTAX       Integer32 (1..2147483647)
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The multiplication unit for vmStorageDefinedSize and
            vmStorageAllocatedSize.  For example, when this value is
            1048576, the storage size unit for vmStorageDefinedSize
            and vmStorageAllocatedSize is MiB."
    ::= { vmStorageEntry 10 }

vmStorageDefinedSize OBJECT-TYPE
    SYNTAX       Integer32 (-1|0..2147483647)
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The defined virtual storage size defined in the unit
            designated by vmStorageSizeUnit.  If this information is
            not available, this value shall be -1."
    ::= { vmStorageEntry 11 }

vmStorageAllocatedSize OBJECT-TYPE
    SYNTAX       Integer32 (-1|0..2147483647)
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The storage size allocated to the virtual storage from
            a physical storage in the unit designated by
            vmStorageSizeUnit.  When the virtual storage is block
            device or raw file, this value and vmStorageDefinedSize
            are supposed to equal.  This value MUST NOT be different
            from vmStorageDefinedSize when vmStorageSourceType is
            `block' or `raw'.  If this information is not available,
            this value shall be -1."
    ::= { vmStorageEntry 12 }

vmStorageReadIOs OBJECT-TYPE
    SYNTAX       Counter64
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The number of read I/O requests.

            Discontinuities in the value of this counter can occur
            at re-initialization of the hypervisor, and
            administrative state (vmAdminState) changes of the
            virtual machine."
    ::= { vmStorageEntry 13 }

vmStorageWriteIOs OBJECT-TYPE
    SYNTAX       Counter64
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The number of write I/O requests.

            Discontinuities in the value of this counter can occur
            at re-initialization of the hypervisor, and
            administrative state (vmAdminState) changes of the
            virtual machine."
    ::= { vmStorageEntry 14 }

-- The virtual network interfaces on each virtual machine.
vmNetworkTable OBJECT-TYPE
    SYNTAX       SEQUENCE OF VmNetworkEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "The conceptual table of virtual network interfaces
            attached to the virtual machine."
    ::= { vmObjects 8 }

vmNetworkEntry OBJECT-TYPE
    SYNTAX       VmNetworkEntry
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "An entry for one virtual network interfaces attached to
            the virtual machine."
    INDEX { vmIndex, vmNetworkIndex }
    ::= { vmNetworkTable 1 }

VmNetworkEntry ::=
    SEQUENCE {
        vmNetworkIndex          VirtualMachineNetworkIndex,
        vmNetworkIfIndex        InterfaceIndexOrZero,
        vmNetworkParent         InterfaceIndexOrZero,
        vmNetworkModel          SnmpAdminString,
        vmNetworkPhysAddress    PhysAddress
    }

vmNetworkIndex OBJECT-TYPE
    SYNTAX       VirtualMachineNetworkIndex
    MAX-ACCESS   not-accessible
    STATUS       current
    DESCRIPTION
            "A unique value identifying a virtual network interface
            allocated to the virtual machine."
    ::= { vmNetworkEntry 1 }

vmNetworkIfIndex OBJECT-TYPE
    SYNTAX       InterfaceIndexOrZero
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The value of ifIndex which corresponds to this virtual
            network interface.  If this device is not represented in
            the ifTable, then this value shall be zero."
    ::= { vmNetworkEntry 2 }

vmNetworkParent OBJECT-TYPE
    SYNTAX       InterfaceIndexOrZero
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The value of ifIndex which corresponds to the parent
            (i.e., physical) device of this virtual device on.  The
            value zero denotes this virtual device is not any child
            represented in the ifTable."
    ::= { vmNetworkEntry 3 }

vmNetworkModel OBJECT-TYPE
    SYNTAX       SnmpAdminString (SIZE (0..255))
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "A textual string containing the (emulated) model of
            virtual network interface.  For example, this value is
            `virtio' when the emulation driver model is virtio."
    ::= { vmNetworkEntry 4 }

vmNetworkPhysAddress OBJECT-TYPE
    SYNTAX       PhysAddress
    MAX-ACCESS   read-only
    STATUS       current
    DESCRIPTION
            "The MAC address of the virtual network interface."
    ::= { vmNetworkEntry 5 }


-- Notification definitions:

vmPerVMNotificationsEnabled OBJECT-TYPE
    SYNTAX       TruthValue
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "Indicates if notification generator will send
            notifications per virtual machine."
    ::= { vmObjects 9 }

vmBulkNotificationsEnabled OBJECT-TYPE
    SYNTAX       TruthValue
    MAX-ACCESS   read-write
    STATUS       current
    DESCRIPTION
            "Indicates if notification generator will send
            notifications per set of virtual machines."
    ::= { vmObjects 10 }

vmAffectedVMs OBJECT-TYPE
    SYNTAX       VirtualMachineList
    MAX-ACCESS   accessible-for-notify
    STATUS       current
    DESCRIPTION
            "A complete list of virtual machines whose state has
            changed.  This object is the only object sent with bulk
            notifications."
    ::= { vmObjects 11 }

vmRunning NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            running(4) from some other state.  The other state is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 1 }

vmShutdown NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            shutdown(12) from some other state.  The other state is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 2 }

vmShuttingdown NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            shuttingdown(11) from some other state.  The other state
            is indicated by the included value of vmOperState."
    ::= { vmNotifications 3 }

vmPaused NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            paused(9) from some other state.  The other state is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 4 }

vmSuspending NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            suspending(6) from some other state.  The other state is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 5 }

vmSuspended NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            suspended(7) from some other state.  The other state is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 6 }

vmResuming NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            resuming(8) from some other state.  The other state is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 7 }

vmMigrating NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            migrating(10) from some other state.  The other state is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 8 }

vmCrashed NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when a virtual machine
            has been crashed.  The previos state of the virtual
            machine is indicated by the included value of
            vmOperState."
    ::= { vmNotifications 9 }

vmBlocked NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of a virtual machine has been changed to
            blocked(5).  The previos state of the virtual machine is
            indicated by the included value of vmOperState."
    ::= { vmNotifications 10 }

vmDeleted NOTIFICATION-TYPE
    OBJECTS      {
                    vmName,
                    vmUUID,
                    vmOperState,
                    vmPersistent
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when a virtual machine
            has been deleted. The prior state of the virtual
            machine is indicated by the included value of
            vmOperState."
    ::= { vmNotifications 11 }

vmBulkRunning NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machine has been changed to
            running(4) from a all prior states except for
            running(4).  Management stations are encouraged to
            subsequently poll the subset of virtual machines of
            interest for vmOperState."
    ::= { vmNotifications 12 }

vmBulkShuttingdown NOTIFICATION-TYPE
    OBJECTS      {
                   vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machine has been changed to
            shuttingdown(11) from a state other than
            shuttingdown(11).  Management stations are encouraged to
            subsequently poll the subset of virtual machines of
            interest for vmOperState."
    ::= { vmNotifications 13 }

vmBulkShutdown NOTIFICATION-TYPE
    OBJECTS      {
                   vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machine has been changed to
            shutdown(12) from a state other than shutdown(12).
            Management stations are encouraged to subsequently poll
            the subset of virtual machines of interest for
            vmOperState."
    ::= { vmNotifications 14 }

vmBulkPaused NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machines have been changed
            to paused(9) from a state other than paused(9).
            Management stations are encouraged to subsequently poll
            the subset of virtual machines of interest for
            vmOperState."
    ::= { vmNotifications 15 }


vmBulkSuspending NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machines have been changed
            to suspending(6) from a state other than suspending(6).
            Management stations are encouraged to subsequently poll
            the subset of virtual machines of interest for
            vmOperState."
    ::= { vmNotifications 16 }

vmBulkSuspended NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machines have been changed
            to suspended(7) from a state other than suspended(7).
            Management stations are encouraged to subsequently poll
            the subset of virtual machines of interest for
            vmOperState."
    ::= { vmNotifications 17 }

vmBulkResuming NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machines have been changed
            to resuming(8) from a state other than resuming(8).
            Management stations are encouraged to subsequently poll
            the subset of virtual machines of interest for
            vmOperState."
    ::= { vmNotifications 18 }

vmBulkMigrating NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machines have been changed
            to migrating(10) from a state other than migrating(10).
            Management stations are encouraged to subsequently poll
            the subset of virtual machines of interest for
            vmOperState."
    ::= { vmNotifications 19 }

vmBulkCrashed NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when one or more virtual
            machines have been crashed.  Management stations are
            encouraged to subsequently poll the subset of virtual
            machines of interest for vmOperState."
    ::= { vmNotifications 20 }

vmBulkBlocked NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when the operational
            state of one or more virtual machines have been changed
            to blocked(5) from a state other than blocked(5).
            Management stations are encouraged to subsequently poll
            the subset of virtual machines of interest for
            vmOperState."
    ::= { vmNotifications 21 }

vmBulkDeleted NOTIFICATION-TYPE
    OBJECTS      {
                    vmAffectedVMs
                 }
    STATUS       current
    DESCRIPTION
            "This notification is generated when one or more virtual
            machines have been deleted.  Management stations are
            encouraged to subsequently poll the subset of virtual
            machines of interest for vmOperState."
    ::= { vmNotifications 22 }

-- Compliance definitions:
vmCompliances  OBJECT IDENTIFIER ::= { vmConformance 1 }
vmGroups       OBJECT IDENTIFIER ::= { vmConformance 2 }

vmFullCompliances MODULE-COMPLIANCE
    STATUS       current
    DESCRIPTION
            "Compliance statement for implementations supporting
            read/write access, according to the object definitions."
    MODULE     -- this module
    MANDATORY-GROUPS {
        vmHypervisorGroup,
        vmVirtualMachineGroup,
        vmCpuGroup,
        vmCpuAffinityGroup,
        vmStorageGroup,
        vmNetworkGroup
    }
    GROUP  vmPerVMNotificationOptionalGroup
    DESCRIPTION
            "Support for per-VM notifications is optional.  If not
            implemented then vmPerVMNotificationsEnabled must report
            false(2)."
    GROUP  vmBulkNotificationsVariablesGroup
    DESCRIPTION
            "Necessary only if vmPerVMNotificationOptionalGroup is
            implemented."
    GROUP  vmBulkNotificationOptionalGroup
    DESCRIPTION
            "Support for bulk notifications is optional.  If not
            implemented then vmBulkNotificationsEnabled must report
            false(2)."

    ::= { vmCompliances 1 }

vmReadOnlyCompliances MODULE-COMPLIANCE
    STATUS       current
    DESCRIPTION
            "Compliance statement for implementations supporting
            only readonly access."
    MODULE     -- this module
    MANDATORY-GROUPS {
        vmHypervisorGroup,
        vmVirtualMachineGroup,
        vmCpuGroup,
        vmCpuAffinityGroup,
        vmStorageGroup,
        vmNetworkGroup
    }

    OBJECT vmAdminState
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmCurCpuNumber
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmMinCpuNumber
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmMaxCpuNumber
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmCurMem
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmMinMem
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmMaxMem
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmCpuAffinity
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmPerVMNotificationsEnabled
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."

    OBJECT vmBulkNotificationsEnabled
    MIN-ACCESS   read-only
    DESCRIPTION
            "Write access is not required."
    ::= { vmCompliances 2 }

vmHypervisorGroup OBJECT-GROUP
    OBJECTS {
        vmHvSoftware,
        vmHvVersion,
        vmHvObjectID,
        vmHvUpTime,
        vmNumber,
        vmTableLastChange,
        vmPerVMNotificationsEnabled,
        vmBulkNotificationsEnabled
    }
    STATUS       current
    DESCRIPTION
            "A collection of objects providing insight into the
            hypervisor itself."
     ::= { vmGroups 1 }

vmVirtualMachineGroup OBJECT-GROUP
    OBJECTS {
        -- vmIndex
        vmName,
        vmUUID,
        vmOSType,
        vmAdminState,
        vmOperState,
        vmAutoStart,
        vmPersistent,
        vmCurCpuNumber,
        vmMinCpuNumber,
        vmMaxCpuNumber,
        vmMemUnit,
        vmCurMem,
        vmMinMem,
        vmMaxMem,
        vmUpTime,
        vmCpuTime
    }
    STATUS       current
    DESCRIPTION
            "A collection of objects providing insight into the
            virtual machines) controlled by a hypervisor."
    ::= { vmGroups 2 }

vmCpuGroup OBJECT-GROUP
    OBJECTS {
        -- vmCpuIndex,
        vmCpuCoreTime
    }
    STATUS       current
    DESCRIPTION
            "A collection of objects providing insight into the
            virtual machines) controlled by a hypervisor."
    ::= { vmGroups 3 }

vmCpuAffinityGroup OBJECT-GROUP
    OBJECTS {
        -- vmCpuPhysIndex,
        vmCpuAffinity
    }
    STATUS       current
    DESCRIPTION
            "A collection of objects providing insight into the
            virtual machines) controlled by a hypervisor."
    ::= { vmGroups 4 }

vmStorageGroup OBJECT-GROUP
    OBJECTS {
        -- vmStorageVmIndex,
        -- vmStorageIndex,
        vmStorageParent,
        vmStorageSourceType,
        vmStorageSourceTypeString,
        vmStorageResourceID,
        vmStorageAccess,
        vmStorageMediaType,
        vmStorageMediaTypeString,
        vmStorageSizeUnit,
        vmStorageDefinedSize,
        vmStorageAllocatedSize,
        vmStorageReadIOs,
        vmStorageWriteIOs
    }
    STATUS       current
    DESCRIPTION
            "A collection of objects providing insight into the
            virtual storage devices controlled by a hypervisor."
    ::= { vmGroups 5 }

vmNetworkGroup OBJECT-GROUP
    OBJECTS {
        -- vmNetworkIndex,
        vmNetworkIfIndex,
        vmNetworkParent,
        vmNetworkModel,
        vmNetworkPhysAddress
    }
    STATUS       current
    DESCRIPTION
            "A collection of objects providing insight into the
            virtual network interfaces controlled by a hypervisor."
    ::= { vmGroups 6 }

vmPerVMNotificationOptionalGroup NOTIFICATION-GROUP
    NOTIFICATIONS {
        vmRunning,
        vmShuttingdown,
        vmShutdown,
        vmPaused,
        vmSuspending,
        vmSuspended,
        vmResuming,
        vmMigrating,
        vmCrashed,
        vmBlocked,
        vmDeleted
    }
    STATUS       current
    DESCRIPTION
            "A collection of notifications for per-VM notification
            of changes to virtual machine state (vmOperState) as
            reported by a hypervisor."
    ::= { vmGroups 7 }

vmBulkNotificationsVariablesGroup OBJECT-GROUP
    OBJECTS {
        vmAffectedVMs
    }
    STATUS       current
    DESCRIPTION
            "The variables used in vmBulkNotificationOptionalGroup
            virtual network interfaces controlled by a hypervisor."
    ::= { vmGroups 8 }

vmBulkNotificationOptionalGroup NOTIFICATION-GROUP
    NOTIFICATIONS {
        vmBulkRunning,
        vmBulkShuttingdown,
        vmBulkShutdown,
        vmBulkPaused,
        vmBulkSuspending,
        vmBulkSuspended,
        vmBulkResuming,
        vmBulkMigrating,
        vmBulkCrashed,
        vmBulkBlocked,
        vmBulkDeleted
    }
    STATUS       current
    DESCRIPTION
            "A collection of notifications for bulk notification of
            changes to virtual machine state (vmOperState) as
            reported by a given hypervisor."
    ::= { vmGroups 9 }

END
      

7. IANA Considerations

The MIB module in this document uses the following IANA-assigned OBJECT IDENTIFIER values recorded in the SMI Numbers registry:

      Descriptor        OBJECT IDENTIFIER value
      ----------        -----------------------

      vmMIB             { mib-2 TBD }
      

8. Security Considerations

There are a number of management objects defined in this MIB that have a MAX-ACCESS clause of read-write and/or read-create. Such objects may be considered sensitive or vulnerable in some network environments. The support for SET operations in a non-secure environment without proper protection can have a negative effect on hypervisor and virtual machine operations.

There are a number of managed objects in this MIB that may contain sensitive information. The objects in the vmHvSoftware and vmHvVersion list information about the hypervisor's software and version. Some may wish not to disclose to others which software they are running. Further, an inventory of the running software and versions may be helpful to an attacker who hopes to exploit software bugs in certain applications. Moreover, the objects in the vmTable, vmCpuTable, vmCpuAffinityTable, vmStorageTable and vmNetworkTable list information about the virtual machines and their virtual resource allocation. Some may wish not to disclose to others how many and what virtual machines they are operating.

It is thus important to control even GET access to these objects and possibly to even encrypt the values of these object when sending them over the network via SNMP. Not all versions of SNMP provide features for such a secure environment.

It is recommended that attention be specifically given to implementing the MAX-ACCESS clause in a number of objects, including vmAdminState, vmMinCpuNumber, vmMaxCpuNumber, vmMinMem, vmMaxMem, and vmCpuAffinity in scenarios that DO NOT use SNMPv3 strong security (i.e. authentication and encryption). Extreme caution must be used to minimize the risk of cascading security vulnerabilities when SNMPv3 strong security is not used. When SNMPv3 strong security is not used, these objects should have access of read-only, not read-create.

SNMPv1 by itself is not a secure environment. Even if the network itself is secure (for example by using IPsec), even then, there is no control as to who on the secure network is allowed to access and GET/SET (read/change/create/delete) the objects in this MIB.

It is recommended that the implementers consider the security features as provided by the SNMPv3 framework. Specifically, the use of the User-based Security Model [RFC3414] and the View-based Access Control Model [RFC3415] is recommended.

It is then a customer/user responsibility to ensure that the SNMP entity giving access to an instance of this MIB, is properly configured to give access to the objects only to those principals (users) that have legitimate rights to indeed GET or SET (change/create/delete) them.

9. Acknowledgements

The authors like to thank Joe Marcus Clarke, Randy Presuhn, and David Black for providing helpful comments during the development of this specification.

Juergen Schoenwaelder was partly funded by Flamingo, a Network of Excellence project (ICT-318488) supported by the European Commission under its Seventh Framework Programme.

10. References

10.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2578] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[RFC2579] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999.
[RFC2580] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 1999.
[RFC2790] Waldbusser, S. and P. Grillo, "Host Resources MIB", RFC 2790, March 2000.
[RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC 2863, June 2000.
[RFC3413] Levi, D., Meyer, P. and B. Stewart, "Simple Network Management Protocol (SNMP) Applications", STD 62, RFC 3413, December 2002.
[RFC3414] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", STD 62, RFC 3414, December 2002.
[RFC3415] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3415, December 2002.
[RFC3418] Presuhn, R., "Management Information Base (MIB) for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3418, December 2002.
[RFC4122] Leach, P., Mealling, M. and R. Salz, "A Universally Unique IDentifier (UUID) URN Namespace", RFC 4122, July 2005.
[RFC6933] Bierman, A., Romascanu, D., Quittek, J. and M. Chandramouli, "Entity MIB (Version 4)", RFC 6933, May 2013.

10.2. Informative References

[RFC3410] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction and Applicability Statements for Internet-Standard Management Framework", RFC 3410, December 2002.

Appendix A. State Transition Table

State transition table
State Action or (Event) Next state Notification
suspended running resuming vmResuming | vmBulkResuming
suspending (suspend operation completed) suspended vmSuspended | vmBulkSuspended
running suspended suspending vmSuspending | vmBulkSuspending
shutdown shuttingdown vmShuttingdown | vmBulkShuttingdown
destroy shutdown vmShutdown | vmBulkShutdown
(migration to other hypervisor initiated) migrating vmMigrating | vmBulkMingrating
resuming (resume opeartion completed) running vmRunning | vmBulkRunning
paused running running vmRunning | vmBulkRunning
shuttingdown (shutdown operation completed) shutdown vmShutdown | vmBulkShutdown
shutdown running running vmRunning | vmBulkRunning
(if this state entry is created by a migration operation (*) migrating vmMigrating | vmBulkMigrating
(deletion operation completed) (no state) vmDeleted | vmBulkDeleted
migrating (migration from other hypervisor completed) running vmRunning | vmBulkRunning
(migration to other hypervisor completed) shutdown vmShutdown | vmBulkShutdown
preparing (preparation completed) shutdown vmShutdown | vmBulkShutdown
blocked (blocking operation completed) (previous state) -
crashed - - -
(any) (blocking operation initiated) blocked vmBlocked | vmBulkBlocked
(crashed) crashed vmCrashed | vmBulkCrashed
(no state) (preparation initiated) preparing -
(migrate from other hypervisor initiated) shutdown (*) vmShutdown | vmBulkShutdown

Authors' Addresses

Hirochika Asai The University of Tokyo 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8656 JP Phone: +81 3 5841 6748 EMail: panda@hongo.wide.ad.jp
Michael MacFaden VMware Inc. EMail: mrm@vmware.com
Juergen Schoenwaelder Jacobs University Campus Ring 1 Bremen 28759, Germany EMail: j.schoenwaelder@jacobs-university.de
Yuji Sekiya (notfirstpage) The University of Tokyo 2-11-16 Yayoi Bunkyo-ku, Tokyo 113-8658 JP EMail: sekiya@wide.ad.jp
Keiichi Shima IIJ Innovation Institute Inc. 3-13 Kanda-Nishikicho Chiyoda-ku, Tokyo 101-0054 JP EMail: keiichi@iijlab.net
Tina Tsou Huawei Technologies (USA) 2330 Central Expressway Santa Clara CA 95050, USA EMail: tina.tsou.zouting@huawei.com
Cathy Zhou (notfirstpage) Huawei Technologies Bantian, Longgang District Shenzhen 518129, P.R. China EMail: cathyzhou@huawei.com
Hiroshi Esaki (notfirstpage) The University of Tokyo 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8656 JP Phone: +81 3 5841 6748 EMail: hiroshi@wide.ad.jp