Feature Support Matrix

Feature Support Matrix

When considering which capabilities should be marked as mandatory the following general guiding principles were applied

  • Inclusivity - people have shown ability to make effective use of a wide range of virtualization technologies with broadly varying featuresets. Aiming to keep the requirements as inclusive as possible, avoids second-guessing what a user may wish to use the cloud compute service for.
  • Bootstrapping - a practical use case test is to consider that starting point for the compute deploy is an empty data center with new machines and network connectivity. The look at what are the minimum features required of a compute service, in order to get user instances running and processing work over the network.
  • Competition - an early leader in the cloud compute service space was Amazon EC2. A sanity check for whether a feature should be mandatory is to consider whether it was available in the first public release of EC2. This had quite a narrow featureset, but none the less found very high usage in many use cases. So it serves to illustrate that many features need not be considered mandatory in order to get useful work done.
  • Reality - there are many virt drivers currently shipped with Nova, each with their own supported feature set. Any feature which is missing in at least one virt driver that is already in-tree, must by inference be considered optional until all in-tree drivers support it. This does not rule out the possibility of a currently optional feature becoming mandatory at a later date, based on other principles above.

Summary

Feature Status Hyper-V Ironic Libvirt KVM (aarch64) Libvirt KVM (ppc64) Libvirt KVM (s390x) Libvirt KVM (x86) Libvirt LXC Libvirt QEMU (x86) Libvirt Virtuozzo CT Libvirt Virtuozzo VM Libvirt Xen PowerVM VMware vCenter XenServer zVM
Attach block volume to instance optional ?
Attach tagged block device to instance optional ?
Detach block volume from instance optional ?
Extend block volume attached to instance optional ? ? ? ? ?
Attach virtual network interface to instance optional
Attach tagged virtual network interface to instance optional ?
Detach virtual network interface from instance optional
Set the host in a maintenance mode optional
Evacuate instances from a host optional ? ? ? ? ? ? ? ? ?
Rebuild instance optional ?
Guest instance status mandatory
Guest host uptime optional
Guest host ip optional
Live migrate instance across hosts optional
Force live migration to complete optional
Launch instance mandatory
Stop instance CPUs (pause) optional
Reboot instance optional
Rescue instance optional ?
Resize instance optional
Restore instance optional
Set instance admin password optional ?
Save snapshot of instance disk optional
Suspend instance optional
Swap block volumes optional ?
Shutdown instance mandatory
Trigger crash dump optional ?
Resume instance CPUs (unpause) optional
uefi boot optional
Device tags optional ? ? ?
quiesce optional ?
unquiesce optional ?
Attach block volume to multiple instances optional ?
Attach encrypted block volume to server optional ? ? ? ? ?
Validate image with trusted certificates optional
File backed memory optional ? ? ?
Report CPU traits optional ?

Details

  • Attach block volume to instance

    Status: optional.

    CLI commands:

    • nova volume-attach <server> <volume>

    Notes: The attach volume operation provides a means to hotplug additional block storage to a running instance. This allows storage capabilities to be expanded without interruption of service. In a cloud model it would be more typical to just spin up a new instance with large storage, so the ability to hotplug extra storage is for those cases where the instance is considered to be more of a pet than cattle. Therefore this operation is not considered to be mandatory to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete

      Notes: This is not tested for every CI run. Add a “powervm:volume-check” comment to trigger a CI job running volume tests.

    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Attach tagged block device to instance

    Status: optional.

    CLI commands:

    • nova volume-attach <server> <volume> [--tag <tag>]

    Notes: Attach a block device with a tag to an existing server instance. See “Device tags” for more information.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Detach block volume from instance

    Status: optional.

    CLI commands:

    • nova volume-detach <server> <volume>

    Notes: See notes for attach volume operation.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete

      Notes: This is not tested for every CI run. Add a “powervm:volume-check” comment to trigger a CI job running volume tests.

    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Extend block volume attached to instance

    Status: optional.

    CLI commands:

    • cinder extend <volume> <new_size>

    Notes: The extend volume operation provides a means to extend the size of an attached volume. This allows volume size to be expanded without interruption of service. In a cloud model it would be more typical to just spin up a new instance with large storage, so the ability to extend the size of an attached volume is for those cases where the instance is considered to be more of a pet than cattle. Therefore this operation is not considered to be mandatory to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: unknown
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: unknown
    • Libvirt KVM (s390x): unknown
    • Libvirt KVM (ppc64): unknown
    • Hyper-V: missing
    • PowerVM: complete

      Notes: This is not tested for every CI run. Add a “powervm:volume-check” comment to trigger a CI job running volume tests.

    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Attach virtual network interface to instance

    Status: optional.

    CLI commands:

    • nova interface-attach <server>

    Notes: The attach interface operation provides a means to hotplug additional interfaces to a running instance. Hotplug support varies between guest OSes and some guests require a reboot for new interfaces to be detected. This operation allows interface capabilities to be expanded without interruption of service. In a cloud model it would be more typical to just spin up a new instance with more interfaces.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: partial

      Notes: Works without issue if instance is off. When hotplugging, only works if using Windows/Hyper-V Server 2016 and the instance is a Generation 2 VM.

    • PowerVM: complete
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: complete
    • zVM: missing

  • Attach tagged virtual network interface to instance

    Status: optional.

    CLI commands:

    • nova interface-attach <server> [--tag <tag>]

    Notes: Attach a virtual network interface with a tag to an existing server instance. See “Device tags” for more information.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Detach virtual network interface from instance

    Status: optional.

    CLI commands:

    • nova interface-detach <server> <port_id>

    Notes: See notes for attach-interface operation.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete

      Notes: Works without issue if instance is off. When hotplugging, only works if using Windows/Hyper-V Server 2016 and the instance is a Generation 2 VM.

    • PowerVM: complete
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: complete
    • zVM: missing

  • Set the host in a maintenance mode

    Status: optional.

    CLI commands:

    • nova host-update <host>

    Notes: This operation allows a host to be placed into maintenance mode, automatically triggering migration of any running instances to an alternative host and preventing new instances from being launched. This is not considered to be a mandatory operation to support. The driver methods to implement are “host_maintenance_mode” and “set_host_enabled”.

    Driver Support:

    • Libvirt QEMU (x86): missing
    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): missing
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): missing
    • Libvirt KVM (ppc64): missing
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: complete
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): missing
    • Ironic: missing
    • zVM: missing

  • Evacuate instances from a host

    Status: optional.

    CLI commands:

    • nova evacuate <server>
    • nova host-evacuate <host>

    Notes: A possible failure scenario in a cloud environment is the outage of one of the compute nodes. In such a case the instances of the down host can be evacuated to another host. It is assumed that the old host is unlikely ever to be powered back on, otherwise the evacuation attempt will be rejected. When the instances get moved to the new host, their volumes get re-attached and the locally stored data is dropped. That happens in the same way as a rebuild. This is not considered to be a mandatory operation to support.

    Driver Support:

    • Libvirt QEMU (x86): unknown
    • Libvirt LXC: unknown
    • Libvirt Xen: unknown
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): unknown
    • Hyper-V: unknown
    • PowerVM: missing
    • VMware vCenter: unknown
    • XenServer: unknown
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): complete
    • Ironic: unknown
    • zVM: unknown

  • Rebuild instance

    Status: optional.

    CLI commands:

    • nova rebuild <server> <image>

    Notes: A possible use case is additional attributes need to be set to the instance, nova will purge all existing data from the system and remakes the VM with given information such as ‘metadata’ and ‘personalities’. Though this is not considered to be a mandatory operation to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: complete
    • zVM: unknown

  • Guest instance status

    Status: mandatory.

    Notes: Provides realtime information about the power state of the guest instance. Since the power state is used by the compute manager for tracking changes in guests, this operation is considered mandatory to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: complete
    • zVM: complete

  • Guest host uptime

    Status: optional.

    Notes: Returns the result of host uptime since power on, it’s used to report hypervisor status.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete
    • VMware vCenter: missing
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: complete

  • Guest host ip

    Status: optional.

    Notes: Returns the ip of this host, it’s used when doing resize and migration.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: complete

  • Live migrate instance across hosts

    Status: optional.

    CLI commands:

    • nova live-migration <server>
    • nova host-evacuate-live <host>

    Notes: Live migration provides a way to move an instance off one compute host, to another compute host. Administrators may use this to evacuate instances from a host that needs to undergo maintenance tasks, though of course this may not help if the host is already suffering a failure. In general instances are considered cattle rather than pets, so it is expected that an instance is liable to be killed if host maintenance is required. It is technically challenging for some hypervisors to provide support for the live migration operation, particularly those built on the container based virtualization. Therefore this operation is not considered mandatory to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): missing
    • Ironic: missing
    • zVM: missing

  • Force live migration to complete

    Status: optional.

    CLI commands:

    • nova live-migration-force-complete <server> <migration>

    Notes: Live migration provides a way to move a running instance to another compute host. But it can sometimes fail to complete if an instance has a high rate of memory or disk page access. This operation provides the user with an option to assist the progress of the live migration. The mechanism used to complete the live migration depends on the underlying virtualization subsystem capabilities. If libvirt/qemu is used and the post-copy feature is available and enabled then the force complete operation will cause a switch to post-copy mode. Otherwise the instance will be suspended until the migration is completed or aborted.

    Driver Support:

    • Libvirt QEMU (x86): complete

      Notes: Requires libvirt>=1.3.3, qemu>=2.5.0

    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete

      Notes: Requires libvirt>=1.3.3, qemu>=2.5.0

    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): complete

      Notes: Requires libvirt>=1.3.3, qemu>=2.5.0

    • Libvirt KVM (ppc64): complete

      Notes: Requires libvirt>=1.3.3, qemu>=2.5.0

    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): missing
    • Ironic: missing
    • zVM: missing

  • Launch instance

    Status: mandatory.

    Notes: Importing pre-existing running virtual machines on a host is considered out of scope of the cloud paradigm. Therefore this operation is mandatory to support in drivers.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: complete
    • zVM: complete

  • Stop instance CPUs (pause)

    Status: optional.

    CLI commands:

    • nova pause <server>

    Notes: Stopping an instances CPUs can be thought of as roughly equivalent to suspend-to-RAM. The instance is still present in memory, but execution has stopped. The problem, however, is that there is no mechanism to inform the guest OS that this takes place, so upon unpausing, its clocks will no longer report correct time. For this reason hypervisor vendors generally discourage use of this feature and some do not even implement it. Therefore this operation is considered optional to support in drivers.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: complete
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: complete

  • Reboot instance

    Status: optional.

    CLI commands:

    • nova reboot <server>

    Notes: It is reasonable for a guest OS administrator to trigger a graceful reboot from inside the instance. A host initiated graceful reboot requires guest co-operation and a non-graceful reboot can be achieved by a combination of stop+start. Therefore this operation is considered optional.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: complete
    • zVM: complete

  • Rescue instance

    Status: optional.

    CLI commands:

    • nova rescue <server>

    Notes: The rescue operation starts an instance in a special configuration whereby it is booted from an special root disk image. The goal is to allow an administrator to recover the state of a broken virtual machine. In general the cloud model considers instances to be cattle, so if an instance breaks the general expectation is that it be thrown away and a new instance created. Therefore this operation is considered optional to support in drivers.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): unknown
    • Ironic: complete
    • zVM: missing

  • Resize instance

    Status: optional.

    CLI commands:

    • nova resize <server> <flavor>

    Notes: The resize operation allows the user to change a running instance to match the size of a different flavor from the one it was initially launched with. There are many different flavor attributes that potentially need to be updated. In general it is technically challenging for a hypervisor to support the alteration of all relevant config settings for a running instance. Therefore this operation is considered optional to support in drivers.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: missing

  • Restore instance

    Status: optional.

    CLI commands:

    • nova resume <server>

    Notes: See notes for the suspend operation

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: missing

  • Set instance admin password

    Status: optional.

    CLI commands:

    • nova set-password <server>

    Notes: Provides a mechanism to (re)set the password of the administrator account inside the instance operating system. This requires that the hypervisor has a way to communicate with the running guest operating system. Given the wide range of operating systems in existence it is unreasonable to expect this to be practical in the general case. The configdrive and metadata service both provide a mechanism for setting the administrator password at initial boot time. In the case where this operation were not available, the administrator would simply have to login to the guest and change the password in the normal manner, so this is just a convenient optimization. Therefore this operation is not considered mandatory for drivers to support.

    Driver Support:

    • Libvirt QEMU (x86): complete

      Notes: Requires libvirt>=1.2.16 and hw_qemu_guest_agent.

    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete

      Notes: Requires libvirt>=1.2.16 and hw_qemu_guest_agent.

    • Libvirt Virtuozzo VM: complete

      Notes: Requires libvirt>=2.0.0

    • Libvirt KVM (s390x): missing
    • Libvirt KVM (ppc64): missing
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: complete

      Notes: Requires XenAPI agent on the guest.

    • Libvirt Virtuozzo CT: complete

      Notes: Requires libvirt>=2.0.0

    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Save snapshot of instance disk

    Status: optional.

    CLI commands:

    • nova image-create <server> <name>

    Notes: The snapshot operation allows the current state of the instance root disk to be saved and uploaded back into the glance image repository. The instance can later be booted again using this saved image. This is in effect making the ephemeral instance root disk into a semi-persistent storage, in so much as it is preserved even though the guest is no longer running. In general though, the expectation is that the root disks are ephemeral so the ability to take a snapshot cannot be assumed. Therefore this operation is not considered mandatory to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: partial

      Notes: Only cold snapshots (pause + snapshot) supported

    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete

      Notes: When using the localdisk disk driver, snapshot is only supported if I/O is being hosted by the management partition. If hosting I/O on traditional VIOS, we are limited by the fact that a VSCSI device can’t be mapped to two partitions (the VIOS and the management) at once.

    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: complete

  • Suspend instance

    Status: optional.

    CLI commands:

    • nova suspend <server>

    Notes: Suspending an instance can be thought of as roughly equivalent to suspend-to-disk. The instance no longer consumes any RAM or CPUs, with its live running state having been preserved in a file on disk. It can later be restored, at which point it should continue execution where it left off. As with stopping instance CPUs, it suffers from the fact that the guest OS will typically be left with a clock that is no longer telling correct time. For container based virtualization solutions, this operation is particularly technically challenging to implement and is an area of active research. This operation tends to make more sense when thinking of instances as pets, rather than cattle, since with cattle it would be simpler to just terminate the instance instead of suspending. Therefore this operation is considered optional to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: missing

  • Swap block volumes

    Status: optional.

    CLI commands:

    • nova volume-update <server> <attachment> <volume>

    Notes: The swap volume operation is a mechanism for changing a running instance so that its attached volume(s) are backed by different storage in the host. An alternative to this would be to simply terminate the existing instance and spawn a new instance with the new storage. In other words this operation is primarily targeted towards the pet use case rather than cattle, however, it is required for volume migration to work in the volume service. This is considered optional to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Shutdown instance

    Status: mandatory.

    CLI commands:

    • nova delete <server>

    Notes: The ability to terminate a virtual machine is required in order for a cloud user to stop utilizing resources and thus avoid indefinitely ongoing billing. Therefore this operation is mandatory to support in drivers.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete

      Notes: Fails in latest Ubuntu Trusty kernel from security repository (3.13.0-76-generic), but works in upstream 3.13.x kernels as well as default Ubuntu Trusty latest kernel (3.13.0-58-generic).

    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: complete
    • VMware vCenter: complete
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: complete
    • zVM: complete

  • Trigger crash dump

    Status: optional.

    CLI commands:

    • nova trigger-crash-dump <server>

    Notes: The trigger crash dump operation is a mechanism for triggering a crash dump in an instance. The feature is typically implemented by injecting an NMI (Non-maskable Interrupt) into the instance. It provides a means to dump the production memory image as a dump file which is useful for users. Therefore this operation is considered optional to support.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: complete
    • zVM: missing

  • Resume instance CPUs (unpause)

    Status: optional.

    CLI commands:

    • nova unpause <server>

    Notes: See notes for the “Stop instance CPUs” operation

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: complete
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: complete

  • uefi boot

    Status: optional.

    Notes: This allows users to boot a guest with uefi firmware.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): missing
    • Libvirt KVM (ppc64): missing
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): complete
    • Ironic: partial

      Notes: depends on hardware support

    • zVM: missing

  • Device tags

    Status: optional.

    CLI commands:

    • nova boot

    Notes: This allows users to set tags on virtual devices when creating a server instance. Device tags are used to identify virtual device metadata, as exposed in the metadata API and on the config drive. For example, a network interface tagged with “nic1” will appear in the metadata along with its bus (ex: PCI), bus address (ex: 0000:00:02.0), MAC address, and tag (nic1). If multiple networks are defined, the order in which they appear in the guest operating system will not necessarily reflect the order in which they are given in the server boot request. Guests should therefore not depend on device order to deduce any information about their network devices. Instead, device role tags should be used. Device tags can be applied to virtual network interfaces and block devices.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: unknown
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: complete
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: complete
    • Libvirt Virtuozzo CT: unknown
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • quiesce

    Status: optional.

    Notes: Quiesce the specified instance to prepare for snapshots. For libvirt, guest filesystems will be frozen through qemu agent.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • unquiesce

    Status: optional.

    Notes: See notes for the quiesce operation

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Attach block volume to multiple instances

    Status: optional.

    CLI commands:

    • nova volume-attach <server> <volume>

    Notes: The multiattach volume operation is an extension to the attach volume operation. It allows to attach a single volume to multiple instances. This operation is not considered to be mandatory to support. Note that for the libvirt driver, this is only supported if qemu<2.10 or libvirt>=3.10.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Attach encrypted block volume to server

    Status: optional.

    CLI commands:

    • nova volume-attach <server> <volume>

    Notes: This is the same as the attach volume operation except with an encrypted block device. Encrypted volumes are controlled via admin-configured volume types in the block storage service. Since attach volume is optional this feature is also optional for compute drivers to support.

    Driver Support:

    • Libvirt QEMU (x86): complete

      Notes: The same restrictions apply as KVM x86.

    • Libvirt LXC: missing
    • Libvirt Xen: unknown
    • Libvirt KVM (x86): complete

      Notes: For native QEMU decryption of the encrypted volume (and rbd support), QEMU>=2.6.0 and libvirt>=2.2.0 are required and only the “luks” type provider is supported. Otherwise both “luks” and “cryptsetup” types are supported but not natively, i.e. not all volume types are supported.

    • Libvirt Virtuozzo VM: unknown
    • Libvirt KVM (s390x): unknown
    • Libvirt KVM (ppc64): unknown
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Validate image with trusted certificates

    Status: optional.

    CLI commands:

    • nova boot --trusted-image-certificate-id ...

    Notes: Since trusted image certification validation is configurable by the cloud deployer it is considered optional. However, it is a virt-agnostic feature so there is no good reason that all virt drivers cannot support the feature since it is mostly just plumbing user requests through the virt driver when downloading images.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: complete
    • Libvirt Xen: complete
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: complete
    • Libvirt KVM (s390x): complete
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: complete
    • Libvirt KVM (aarch64): complete
    • Ironic: missing
    • zVM: missing

  • File backed memory

    Status: optional.

    Notes: The file backed memory feature in Openstack allows a Nova node to serve guest memory from a file backing store. This mechanism uses the libvirt file memory source, causing guest instance memory to be allocated as files within the libvirt memory backing directory. This is only supported if qemu>2.6 and libivrt>4.0.0

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): unknown
    • Libvirt KVM (ppc64): unknown
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

  • Report CPU traits

    Status: optional.

    Notes: The report CPU traits feature in OpenStack allows a Nova node to report its CPU traits according to CPU mode configuration. This gives users the ability to boot instances based on desired CPU traits.

    Driver Support:

    • Libvirt QEMU (x86): complete
    • Libvirt LXC: missing
    • Libvirt Xen: missing
    • Libvirt KVM (x86): complete
    • Libvirt Virtuozzo VM: missing
    • Libvirt KVM (s390x): missing
    • Libvirt KVM (ppc64): complete
    • Hyper-V: missing
    • PowerVM: missing
    • VMware vCenter: missing
    • XenServer: missing
    • Libvirt Virtuozzo CT: missing
    • Libvirt KVM (aarch64): unknown
    • Ironic: missing
    • zVM: missing

Notes:

  • This document is a continuous work in progress
Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.