15.6. Sub-Collections

15.6.1. Disks Sub-Collection

15.6.1.1. Disks Sub-Collection

The disks sub-collection represents all virtual hard disk devices on a virtual machine. A disk representation contains the following elements:

Table 15.2. Elements for virtual disks

Element Type Description Properties
link rel="statistics" relationship A link to the statistics sub-collection for a virtual machine's disk statistics.
link rel="permissions" relationship A link to the permissions sub-collection.
alias string The unique identifier for the disk. Use alias instead of name.
image_id string A reference to the virtual machine image stored on the defined storage domain.
storage_domains complex The storage domains associated with this disk. Each storage_domain element contains an id attribute with the associated storage domain's GUID. Update this element with POST to perform live migration of a disk from one data storage domain to another. [a]
size integer Size of the disk in bytes. Deprecated; replaced by provisioned_size.
provisioned_size integer The provisioned size of the disk in bytes.
actual_size integer Actual size of the disk in bytes.
status One of illegal, invalid, locked or ok The status of the disk device. These states are listed in disk_states under capabilities.
interface enumerated The type of interface driver used to connect to the disk device. A list of enumerated values is available in capabilities.  
format enumerated The underlying storage format. A list of enumerated values is available in capabilities. Copy On Write (COW) allows snapshots, with a small performance overhead. Raw does not allow snapshots, but offers improved performance.
sparse Boolean: true or false true if the physical storage for the disk should not be preallocated.
bootable Boolean: true or false true if this disk is to be marked as bootable.  
shareable Boolean: true or false true to share the disk with multiple virtual machines.  
wipe_after_delete Boolean: true or false true if the underlying physical storage for the disk should be zeroed when the disk is deleted. This increases security but is a more intensive operation and may prolong delete times.  
propagate_errors Boolean: true or false true if disk errors should not cause virtual machine to be paused and, instead, disk errors should be propagated to the guest OS.  
vm id= GUID The ID of the containing virtual machine.
quota id= GUID Sets a quota for the disk.  
lun_storage complex A reference to a direct LUN mapping for storage usage. Requires a logical_unit element that contains iSCSI or FCP device details.
active Boolean Defines if the disk is connected to the virtual machine.
read_only Boolean Defines if the disk is read-only.
link rel="disk_profile" relationship A link to the disk_profile sub-collection.
[a] This element is only required if the disk is being added to a virtual machine and not created from a virtual machine template.

Example 15.11. An XML representation of a disk device

<disk id="ed7feafe-9aaf-458c-809a-ed789cdbd5b4"
  href="/ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks/
  ed7feafe-9aaf-458c-809a-ed789cdbd5b4">
    <link rel="statistics"
      href="/ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks/
      ed7feafe-9aaf-458c-809a-ed789cdbd5b4/statistics"/>
    <link rel="permissions"
      href="/ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks/
      ed7feafe-9aaf-458c-809a-ed789cdbd5b4/permissions"/>
    <vm id="082c794b-771f-452f-83c9-b2b5a19c0399"
      href="/ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399"/> 
    <alias>Classic_VM</alias>
    <image_id>cac69a29-ccff-49d4-8a26-e4cdacd83e34</image_id> 
    <storage_domains>
        <storage_domain id="fabe0451-701f-4235-8f7e-e20e458819ed"/>
    </storage_domains> 
    <size>12884901888</size>
    <provisioned_size>12884901888</provisioned_size>
    <actual_size>1073741824</actual_size>
    <type>system</type>
    <status>
        <state>ok</state>
    </status>
    <interface>virtio</interface>
    <format>raw</format>
    <bootable>true</bootable>
    <shareable>true</shareable>
    <wipe_after_disk>true</wipe_after_disk>
    <propagate_errors>false</propagate_errors>
    <active>true</active>
    <read_only>false</read_only>
    <disk_profile id="23fb2e0d-3062-4819-8165-3be88f2f587e"
      href="/ovirt-engine/api/diskprofiles/23fb2e0d-3062-4819-8165-3be88f2f587e"/>
    <lun_storage>
        <logical_unit id="lun1">
                ...
        </logical_unit>
    </lun_storage>
</disk>

Add a new virtual disk. When adding a new internal disk, the provisioned_size element is required. Use the storage_domains element to specify in which storage domain the disk will be created. Multiple disks for the same virtual machine can reside in different storage domains.

Example 15.12. Creating a new disk device on a virtual machine

POST /ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks HTTP/1.1
Accept: application/xml
Content-type: application/xml

<disk>
    <storage_domains>
        <storage_domain id="fabe0451-701f-4235-8f7e-e20e458819ed"/>
    </storage_domains>        
    <provisioned_size>8589934592</provisioned_size>
    <type>system</type>
    <interface>virtio</interface>
    <format>cow</format>
    <bootable>true</bootable>
</disk>
Add a new external (direct LUN) disk to a virtual machine. This method requires the lun_storage element and the logical_unit element, which contains iSCSI or FCP device details.

Example 15.13. Creating a new direct LUN disk device on a virtual machine

POST /ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks HTTP/1.1
Accept: application/xml
Content-type: application/xml
		
<disk>
    <interface>virtio</interface>
    <lun_storage>
        <type>iscsi</type>
        <logical_unit id="lun1">
            <address>iscsi.example.com</address>
            <port>3260</port>
            <target>iqn.2010.05.com.example:iscsi.targetX</target>
        </logical_unit>
    </lun_storage>
</disk>
The alias, description, storage_domains, provisioned_size, interface, bootable, shareable, wipe_after_delete and propagate_errors elements are updatable post-creation.
Users can resize virtual disks that are in use by one or more virtual machines, without pausing, hibernating or rebooting the virtual machine(s).

Example 15.14. Updating a virtual disk

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/disks/ed7feafe-9aaf-458c-809a-ed789cdbd5b4 HTTP/1.1
Accept: application/xml
Content-type: application/xml

<disk>
    <bootable>false</bootable>
    <shareable>false</shareable>
</disk>

Example 15.15. Updating a virtual disk to 20GB

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/disks/ed7feafe-9aaf-458c-809a-ed789cdbd5b4 HTTP/1.1
Accept: application/xml
Content-type: application/xml

<disk>
    <provisioned_size>21474836480</provisioned_size>
</disk>

Note

Disk size in the previous example is converted to bytes using the following formula:
20480MB * 1024 2 = 21474836480 bytes

Example 15.16. Renaming a virtual disk

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/disks/ed7feafe-9aaf-458c-809a-ed789cdbd5b4 HTTP/1.1
Accept: application/xml
Content-type: application/xml

<disk>
    <alias>Classic_VM2</alias>
</disk>
Removal of a virtual disk requires a DELETE request.

Example 15.17. Removing a virtual disk

DELETE /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/disks/ed7feafe-9aaf-458c-809a-ed789cdbd5b4 HTTP/1.1

HTTP/1.1 204 No Content

15.6.1.2. Disk Cloning

Clone a disk from a template with the clone element. Set the clone element to true within the disks sub-collection when creating a virtual machine. This clones a disk from the base template and attaches it to the virtual machine.

Example 15.18. Cloning a disk from a template

The following example clones a disk from a template during the creation of a virtual machine.
POST /ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399 HTTP/1.1
Accept: application/xml
Content-type: application/xml
        
<vm>
    <name>cloned_vm</name>
    <template id="64d4aa08-58c6-4de2-abc4-89f19003b886"/>
    <cluster id="99408929-82cf-4dc7-a532-9d998063fa95"/>
    <disks>
        <clone>true</clone>
        <disk id="4825ffda-a997-4e96-ae27-5503f1851d1b">
            <format>COW</format>
        </disk>
        <disk id="42aef10d-3dd5-4704-aa73-56a023c1464c">
            <format>COW</format>
        </disk>
    </disks>
</vm>

Important

Search queries for virtual disks based upon disk name require the alias search parameter instead of name.

15.6.1.3. Disk Statistics Sub-Collection

Each virtual machine's disk exposes a statistics sub-collection for disk-specific statistics. Each statistic contains the following elements:

Table 15.3. Elements for virtual disk statistics

Element Type Description
name string The unique identifier for the statistic entry.
description string A plain text description of the statistic.
unit string The unit or rate to measure the statistical values.
type One of GAUGE or COUNTER The type of statistic measures.
values type= One of INTEGER or DECIMAL The data type for the statistical values that follow.
value complex A data set that contains datum.
datum see values type An individual piece of data from a value.
disk id= relationship A relationship to the containing disk resource.
The following table lists the statistic types for virtual disks.

Table 15.4. Virtual disk statistic types

Name
Description
data.current.read
The data transfer rate in bytes per second when reading from the disk.
data.current.write
The data transfer rate in bytes per second when writing to the disk.

Example 15.19. An XML representation of a virtual machine's statistics sub-collection

<statistics>
    <statistic id="33b9212b-f9cb-3fd0-b364-248fb61e1272"
      href="/ovirt-engine/api/vms/3a42530e-3bc5-4094-829d-489257894c2a/disks/
      f28ec14c-fc85-43e1-818d-96b49d50e27b/statistics/
      33b9212b-f9cb-3fd0-b364-248fb61e1272">
        <name>data.current.read</name>
        <description>Read data rate</description>
        <values type="DECIMAL">
            <value>
                <datum>0</datum>
            </value>
        </values>
        <type>GAUGE</type>
        <unit>BYTES_PER_SECOND</unit>
        <disk id="f28ec14c-fc85-43e1-818d-96b49d50e27b" 
          href="/ovirt-engine/api/vms/3a42530e-3bc5-4094-829d-489257894c2a/
          disks/f28ec14c-fc85-43e1-818d-96b49d50e27b"/>
    </statistic>
    ...
</statistics>

Note

This statistics sub-collection is read-only.

15.6.1.4. Floating Disk Attach and Detach Actions

Attach a disk from the main rel="disks" collection using a POST request on the virtual machine's disks sub-collection. Include the id of the disk to attach.

Example 15.20. Attach a floating disk

POST /ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks HTTP/1.1
Accept: application/xml
Content-type: application/xml

<disk id="d135f1c5-b5e1-4238-9381-b3277f5a3742">
</disk>
Detach a disk from a virtual machine's disks sub-collection using a DELETE request on the disk resource but ensure to include a detach Boolean element so the disk is not destroyed.

Example 15.21. Detach a disk from a virtual machine

DELETE /ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks/
  d135f1c5-b5e1-4238-9381-b3277f5a3742 HTTP/1.1
Accept: application/xml
Content-type: application/xml

<action>
    <detach>true</detach>
</action>

15.6.1.5. Disk Activate and Deactivate Actions

Each virtual machine's disk provides a set of activate and deactivate actions to add and remove disks from a virtual machine.

Example 15.22. Action to activate a virtual disk

POST /ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks/a42ada0e-1d69-410d-a392-a6980d873e5d/activate HTTP/1.1
Accept: application/xml
Content-type: application/xml

<action/>

Example 15.23. Action to deactivate a virtual disk

POST /ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/disks/a42ada0e-1d69-410d-a392-a6980d873e5d/deactivate HTTP/1.1
Accept: application/xml
Content-type: application/xml

<action/>
Use these actions to hotplug disks to virtual machines and activate newly attached floating disks.

Important

The hotplugging feature only supports VirtIO disks and virtual machine operating systems that support hotplugging operations. Example operating systems include:
  • Red Hat Enterprise Linux 6;
  • Red Hat Enterprise Linux 5;
  • Windows Server 2008; and,
  • Windows Server 2003.

15.6.2. Network Interfaces Sub-Collection

15.6.2.1. Network Interfaces Sub-Collection

The nics sub-collection represents all network interface devices on a virtual machine. A nic representation contains the following elements:

Table 15.5. Elements for virtual machine network interfaces

Element Type Description Properties
link rel="statistics" relationship A link to the statistics sub-collection for a virtual machine's network interface statistics.
network id= GUID A reference to the network which the interface should be connected. A blank network id is allowed.
interface enumerated The type of driver used for the nic. A list of enumerated values is available in capabilities.  
mac address= string The MAC address of the interface.
port_mirroring complex Defines whether the NIC receives mirrored traffic. Define a networks element with a series of network id= references.
plugged Boolean Defines if the NIC is plugged in to the virtual machine.
linked Boolean Defines if the NIC is linked to the virtual machine.

Example 15.24. An XML representation of a network interface

<nic id="7a3cff5e-3cc4-47c2-8388-9adf16341f5e" 
  ref="/ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/nics/
  7a3cff5e-3cc4-47c2-8388-9adf16341f5e">
    <link rel="statistics"
      href="/ovirt-engine/api/vms/082c794b-771f-452f-83c9-b2b5a19c0399/nics/
      7a3cff5e-3cc4-47c2-8388-9adf16341f5e/statistics"/>   
    <name>nic1</name>
    <interface>virtio</interface>
    <mac address="00:1a:4a:16:84:07"/>
    <network id="00000000-0000-0000-0000-000000000009"
      href="/ovirt-engine/api/networks/00000000-0000-0000-0000-000000000009"/>
    <vm id="cdc0b102-fbfe-444a-b9cb-57d2af94f401"
      href="/ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401"/>
    <port_mirroring>
        <networks>
            <network id="56087282-d7a6-11e1-af44-001a4a400e0c"
              href="/ovirt-engine/api/networks/56087282-d7a6-11e1-af44-001a4a400e0c"/>
        </networks>
    </port_mirroring>
</nic>
When adding a new network interface, the name and network elements are required. Identify the network element with the id attribute or name element.

Example 15.25. Creating a virtual machine NIC

POST /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/nics HTTP/1.1
Accept: application/xml
Content-type: application/xml

<nic>
    <name>nic1</name>
    <network id="00000000-0000-0000-0000-000000000009"/>
</nic>
An API user modifies a network interface with a PUT request.

Example 15.26. Updating a virtual machine NIC

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/nics/
7a3cff5e-3cc4-47c2-8388-9adf16341f5e HTTP/1.1
Accept: application/xml
Content-type: application/xml

<nic>
    <name>nic2</name>
    <network id="00000000-0000-0000-0000-000000000010"/>
    <type>e1000</type>
</nic>
An API user removes a network interface with a DELETE request.

Example 15.27. Deleting a virtual machine NIC

DELETE /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/nics/
7a3cff5e-3cc4-47c2-8388-9adf16341f5e HTTP/1.1

HTTP/1.1 204 No Content

Important

The hotplugging feature only supports virtual machine operating systems with hotplugging operations. Example operating systems include:
  • Red Hat Enterprise Linux 6;
  • Red Hat Enterprise Linux 5;
  • Windows Server 2008; and,
  • Windows Server 2003.

15.6.2.2. Network Interface Statistics Sub-Collection

Each virtual machine's network interface exposes a statistics sub-collection for network interface statistics. Each statistic contains the following elements:

Table 15.6. Elements for a virtual machine's network interface statistics

Element Type Description
name string The unique identifier for the statistic entry.
description string A plain text description of the statistic.
unit string The unit or rate to measure the statistical values.
type One of GAUGE or COUNTER The type of statistic measures.
values type= One of INTEGER or DECIMAL The data type for the statistical values that follow.
value complex A data set that contains datum.
datum see values type An individual piece of data from a value.
nic id= relationship A relationship to the containing nic resource.
The following table lists the statistic types for network interfaces on virtual machines.

Table 15.7. Virtual machine NIC statistic types

Name
Description
data.current.rx
The rate in bytes per second of data received.
data.current.tx
The rate in bytes per second of data transmitted.
errors.total.rx
Total errors from receiving data.
errors.total.tx
Total errors from transmitting data.

Example 15.28. An XML representation of a virtual machine's NIC statistics sub-collection

<statistics>
    <statistic id="ecd0559f-e88f-3330-94b4-1f091b0ffdf7"
      href="/ovirt-engine/api/vms/3a42530e-3bc5-4094-829d-489257894c2a/nics/
      6cd08e76-57c0-41ba-a728-7eba46ae1e36/statistics/
      ecd0559f-e88f-3330-94b4-1f091b0ffdf7">
        <name>data.current.rx</name>
        <description>Receive data rate</description>
        <values type="DECIMAL">
            <value>
                <datum>0</datum>
            </value>
        </values>
        <type>GAUGE</type>
        <unit>BYTES_PER_SECOND</unit>
        <nic id="6cd08e76-57c0-41ba-a728-7eba46ae1e36"
          href="/ovirt-engine/api/vms/3a42530e-3bc5-4094-829d-489257894c2a/
          nics/6cd08e76-57c0-41ba-a728-7eba46ae1e36"/>
    </statistic>
    ...
</statistics>

Note

This statistics sub-collection is read-only.

15.6.3. Virtual NUMA Nodes Sub-Collection

The numanodes sub-collection represents all virtual NUMA nodes on a virtual machine. A vm_numa_node representation contains the following elements:

Table 15.8. Elements for virtual NUMA nodes

Element Type Description Properties
index integer The index number of the virtual NUMA node.
memory integer The amount of memory allocated to the virtual NUMA node, in MB.
cpu complex The CPU topology associated with this virtual NUMA node. Each core element contains an index attribute with the associated core's index number.
vm id= GUID The ID of the containing virtual machine.
numa_node_pins complex Pins the virtual NUMA node to a host NUMA node. Each numa_node_pin element contains a pinned="true" boolean and the host NUMA node's index number.  

Example 15.29. An XML representation of a virtual NUMA node

<vm_numa_node href="/ovirt-engine/api/vms/c7ecd2dc-dbd3-4419-956f-1249651c0f2b/numanodes/3290b973-ed3e-4f0b-bbf5-9be10d229e50" id="3290b973-ed3e-4f0b-bbf5-9be10d229e50">
        <index>0</index>
        <memory>1024</memory>
        <cpu>
            <cores>
                <core index="0"/>
            </cores>
        </cpu>
        <vm href="/ovirt-engine/api/vms/c7ecd2dc-dbd3-4419-956f-1249651c0f2b" id="c7ecd2dc-dbd3-4419-956f-1249651c0f2b"/>
        <numa_node_pins>
            <numa_node_pin pinned="true" index="0">
                <host_numa_node id="417cdefb-8c47-4838-87f3-dd0498fdf6c7"/>
            </numa_node_pin>
        </numa_node_pins>
</vm_numa_node>
When adding a new virtual NUMA node, the index, memory, and cpu elements are required.

Example 15.30. Adding a new virtual NUMA node to a virtual machine

POST /ovirt-engine/api/vms/c7ecd2dc-dbd3-4419-956f-1249651c0f2b/numanodes HTTP/1.1
Accept: application/xml
Content-type: application/xml

<vm_numa_node>
  <index>0</index>
  <memory>1024</memory>
  <cpu>
    <cores>
      <core index="0"/>
    </cores>
  </cpu>
</vm_numa_nodes>
Update a virtual NUMA node with a PUT request. You can use a PUT request to pin a virtual NUMA node to a physical NUMA node on a host.

Example 15.31. Updating a virtual NUMA node

PUT /ovirt-engine/api/vms/c7ecd2dc-dbd3-4419-956f-1249651c0f2b/numanodes/3290b973-ed3e-4f0b-bbf5-9be10d229e50 HTTP/1.1
Accept: application/xml
Content-type: application/xml

<vm_numa_node>
  <numa_node_pins>
    <numa_node_pin pinned="true" index="0">
      <host_numa_node id="417cdefb-8c47-4838-87f3-dd0498fdf6c7"/>
    </numa_node_pin>
  </numa_node_pins>
</vm_numa_node>
Remove a virtual NUMA node with a DELETE request.

Example 15.32. Removing a virtual NUMA node

DELETE /ovirt-engine/api/vms/c7ecd2dc-dbd3-4419-956f-1249651c0f2b/numanodes/3290b973-ed3e-4f0b-bbf5-9be10d229e50 HTTP/1.1

HTTP/1.1 204 No Content

15.6.4. CD-ROMs Sub-Collection

The cdroms sub-collection represents the CD-ROM device on a virtual machine. A cdrom representation contains the following elements:

Table 15.9. Elements for virtual machine CD-ROMs

Element Type Description Properties
file id= string/filename A reference to an ISO image.  

Example 15.33. An XML representation of a CD-ROM device

<cdrom id="00000000-0000-0000-0000-000000000000"
  href="/ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/cdroms/
  00000000-0000-0000-0000-000000000000">
    <file id="rhel-server-6.0-x86_64-dvd.iso"/>
    <vm id="cdc0b102-fbfe-444a-b9cb-57d2af94f401"
      href="/ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401"/>
</cdrom>
Send a PUT request with a file id element to add a new CD-ROM resource.

Example 15.34. Adding a new CD-ROM file

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/cdroms/00000000-0000-0000-0000-000000000000 HTTP/1.1
Accept: application/xml
Content-type: application/xml
      
<cdrom>
    <file id="fedora-15-x86_64-dvd.iso"/>
</cdrom>
The API changes the CD-ROM using a PUT request:

Example 15.35. Changing a CD-ROM file

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/cdroms/00000000-0000-0000-0000-000000000000 HTTP/1.1
Accept: application/xml
Content-type: application/xml
      
<cdrom>
    <file id="fedora-15-x86_64-dvd.iso"/>
</cdrom>
The API changes the CD-ROM for the current session only using a PUT request with an additional current URI argument:

Example 15.36. Changing a CD-ROM file during a current session

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/cdroms/00000000-0000-0000-0000-000000000000;current=true HTTP/1.1
Accept: application/xml
Content-type: application/xml
      
<cdrom>
    <file id="fedora-15-x86_64-dvd.iso"/>
</cdrom>
To eject the CD-ROM temporarily, send a PUT request to the cdroms sub-collection of a virtual machine, adding the current=true matrix parameter:

Example 15.37. Ejecting a CD-ROM file during a current session

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/cdroms/00000000-0000-0000-0000-000000000000;current=true HTTP/1.1
Accept: application/xml
Content-type: application/xml
<cdrom>
  <file id=""/>
</cdrom>

Note

Rebooting the virtual machine will connect the CD-ROM again.
To eject the CD-ROM permanently, send a PUT request to the cdroms sub-collection of a virtual machine:

Example 15.38. Ejecting a CD-ROM file permanently

PUT /ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/cdroms/00000000-0000-0000-0000-000000000000 HTTP/1.1
Accept: application/xml
Content-type: application/xml
<cdrom>
  <file id=""/>
</cdrom>

Note

Virtual machines only contain a single CD-ROM device.

15.6.5. Snapshots Sub-Collection

15.6.5.1. Snapshots Sub-Collection

A virtual machine saves and restores disk state as a number of snapshots. These are represented and managed through a rel="snapshot" sub-collection that behaves similar to other collections.
Each virtual machine snapshot is represented with an individual snapshot element that contains the following sub-elements:

Table 15.10. Elements for virtual machine snapshots

Element Type Description Properties
vm id= GUID The ID and URI of the virtual machine to which this snapshot pertains.
link rel="restore" relationship A link to restore the snapshot of the virtual machine.
link rel="prev" relationship A link to the previous snapshot of this virtual machine.
type string The type of the snapshot. For example, active or regular.
date xsd:dateTime format: YYYY-MM-DDThh:mm:ss The date and time at which the snapshot was created.
snapshot_status string The current status of the snapshot.
persist_memorystate Boolean Defines whether the snapshot also includes the state of the memory of the virtual machine at the time the snapshot was taken.

Note

It is not possible to modify snapshot elements using PUT.

Example 15.39. An XML representation of a virtual machine snapshot

<snapshot id="00000000-0000-0000-0000-000000000000"
  href="/ovirt-engine/api/vms/00000000-0000-0000-0000-000000000000/snapshots/
  00000000-0000-0000-0000-000000000000">
    <actions>
      <link rel="restore"
      href="/ovirt-engine/api/vms/00000000-0000-0000-0000-000000000000/snapshots/
      00000000-0000-0000-0000-000000000000/restore"/>
    <link rel="prev"
      href="/ovirt-engine/api/vms/00000000-0000-0000-0000-000000000000/snapshots/
    </actions>
    <vm id="00000000-0000-0000-0000-000000000000"
      href="/ovirt-engine/api/vms/00000000-0000-0000-0000-000000000000"/>
    <description>Virtual Machine 1 - Snapshot A</description>
    <type>active</type>
    <date>2010-08-16T14:24:29</date>
    <snapshot_status>ok</snapshot_status>
    <persist_memorystate>false</persist_memorystate>
</snapshot>
Use a GET request for a virtual machine snapshot with the All-Content: true header to include additional OVF data with the representation of the snapshot.
The Accept header defaults to application/xml if left blank, and the data is represented with HTML entities so as not to interfere with the XML tags. Specifying the Accept: application/json header will return the data in standard XML tagging. This example representation has been formatted from its standard block format to improve legibility.

Example 15.40. XML representation of additional ovf data for a snapshot

GET /ovirt-engine/api/vms/42ec2621-7ad6-4ca2-bd68-973a44b2562e/snapshots HTTP/1.1
All-Content: true
	
<?xml version='1.0' encoding='UTF-8'?>
<ovf:Envelope xmlns:ovf=\"http://schemas.dmtf.org/ovf/envelope/1/\" 
  xmlns:rasd=\"http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_ResourceAllocationSettingData\" 
  xmlns:vssd=\"http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/CIM_VirtualSystemSettingData\" 
  xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" ovf:version=\"3.5.0.0\"> 
  <References>
  <File ovf:href=\"ad353554-f668-46cf-aa3c-e57383de2c92/40456d92-3687-4a85-bab3-87b4cc7af459\" 
    ovf:id=\"40456d92-3687-4a85-bab3-87b4cc7af459\" ovf:size=\"10737418240\" 
    ovf:description=\"Active VM\"/>
  <Nic ovf:id=\"be14bfc8-3dbd-4ac1-ba02-c6dfa7fc707c\"/>
  </References>
  <Section xsi:type=\"ovf:NetworkSection_Type\"> 
    <Info>List of networks</Info><Network ovf:name=\"Network 1\"/>
  </Section>
  <Section 
    xsi:type=\"ovf:DiskSection_Type\"> 
    <Info>List of Virtual Disks</Info>
    <Disk ovf:diskId=\"40456d92-3687-4a85-bab3-87b4cc7af459\" 
    ovf:size=\"10\" ovf:actual_size=\"0\" 
    ovf:vm_snapshot_id=\"a209216d-2909-4802-8886-02aad55dccc8\" 
    ovf:parentRef=\"\" 
    ovf:fileRef=\"ad353554-f668-46cf-aa3c-e57383de2c92/40456d92-3687-4a85-bab3-87b4cc7af459\" 
    ovf:format=\"http://www.vmware.com/specifications/vmdk.html#sparse\" 
    ovf:volume-format=\"RAW\" 
    ovf:volume-type=\"Preallocated\" 
    ovf:disk-interface=\"VirtIO\" 
    ovf:boot=\"true\" 
    ovf:disk-alias=\"VM_01_Disk1\" 
    ovf:wipe-after-delete=\"false\"/>
  </Section>
  <Content 
    ovf:id=\"out\" 
    xsi:type=\"ovf:VirtualSystem_Type\"> 
    <CreationDate>2015/02/09 13:53:53</CreationDate> 
    <ExportDate>2015/02/10 00:39:24</ExportDate> 
    <DeleteProtected>false</DeleteProtected> 
    <SsoMethod>guest_agent</SsoMethod> 
    <IsSmartcardEnabled>false</IsSmartcardEnabled> 
    <TimeZone>Etc/GMT</TimeZone><default_boot_sequence>0</default_boot_sequence> 
    <Generation>1</Generation> 
    <VmType>1</VmType> 
    <MinAllocatedMem>1024</MinAllocatedMem> 
    <IsStateless>false</IsStateless> 
    <IsRunAndPause>false</IsRunAndPause> 
    <AutoStartup>false</AutoStartup> 
    <Priority>1</Priority> 
    <CreatedByUserId>fdfc627c-d875-11e0-90f0-83df133b58cc</CreatedByUserId> 
    <IsBootMenuEnabled>false</IsBootMenuEnabled> 
    <IsSpiceFileTransferEnabled>true</IsSpiceFileTransferEnabled> 
    <IsSpiceCopyPasteEnabled>true</IsSpiceCopyPasteEnabled> 
    <Name>VM_01</Name> 
    <TemplateId>00000000-0000-0000-0000-000000000000</TemplateId> 
    <TemplateName>Blank</TemplateName> 
    <IsInitilized>true</IsInitilized> 
    <Origin>3</Origin> 
    <DefaultDisplayType>1</DefaultDisplayType> 
    <TrustedService>false</TrustedService> 
    <OriginalTemplateId>00000000-0000-0000-0000-000000000000</OriginalTemplateId> 
    <OriginalTemplateName>Blank</OriginalTemplateName> 
    <UseLatestVersion>false</UseLatestVersion>
    <Section ovf:id=\"42ec2621-7ad6-4ca2-bd68-973a44b2562e\" ovf:required=\"false\" xsi:type=\"ovf:OperatingSystemSection_Type\"> 
      <Info>Guest Operating System</Info> 
      <Description>other</Description>
    </Section>
    <Section xsi:type=\"ovf:VirtualHardwareSection_Type\"> 
      <Info>1 CPU, 1024 Memeory</Info> 
      <System>
        <vssd:VirtualSystemType>ENGINE 3.5.0.0</vssd:VirtualSystemType>
      </System> 
      <Item> 
        <rasd:Caption>1 virtual cpu</rasd:Caption> 
        <rasd:Description>Number of virtual CPU</rasd:Description> 
        <rasd:InstanceId>1</rasd:InstanceId> 
        <rasd:ResourceType>3</rasd:ResourceType> 
        <rasd:num_of_sockets>1</rasd:num_of_sockets> 
        <rasd:cpu_per_socket>1</rasd:cpu_per_socket>
      </Item> 
      <Item> 
        <rasd:Caption>1024 MB of memory</rasd:Caption> 
        <rasd:Description>Memory Size</rasd:Description> 
        <rasd:InstanceId>2</rasd:InstanceId> 
        <rasd:ResourceType>4</rasd:ResourceType> 
        <rasd:AllocationUnits>MegaBytes</rasd:AllocationUnits> 
        <rasd:VirtualQuantity>1024</rasd:VirtualQuantity>
      </Item> 
      <Item> 
        <rasd:Caption>VM_01_Disk1</rasd:Caption> 
        <rasd:InstanceId>40456d92-3687-4a85-bab3-87b4cc7af459</rasd:InstanceId> 
        <rasd:ResourceType>17</rasd:ResourceType> 
        <rasd:HostResource>ad353554-f668-46cf-aa3c-e57383de2c92/40456d92-3687-4a85-bab3-87b4cc7af459</rasd:HostResource> 
        <rasd:Parent>00000000-0000-0000-0000-000000000000</rasd:Parent> 
        <rasd:Template>00000000-0000-0000-0000-000000000000</rasd:Template> 
        <rasd:ApplicationList></rasd:ApplicationList> 
        <rasd:StoragePoolId>00000002-0002-0002-0002-000000000255</rasd:StoragePoolId> 
        <rasd:CreationDate>2015/02/09 13:54:41</rasd:CreationDate> 
        <rasd:LastModified>1970/01/01 00:00:00</rasd:LastModified> 
        <rasd:last_modified_date>2015/02/10 00:39:22</rasd:last_modified_date> 
        <Type>disk</Type> 
        <Device>disk</Device> 
        <rasd:Address>{slot=0x06, bus=0x00, domain=0x0000, type=pci, function=0x0}</rasd:Address> 
        <BootOrder>1</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>virtio-disk0</Alias>
      </Item> 
      <Item> 
        <rasd:Caption>Ethernet adapter on ovirtmgmt</rasd:Caption> 
        <rasd:InstanceId>be14bfc8-3dbd-4ac1-ba02-c6dfa7fc707c</rasd:InstanceId> 
        <rasd:ResourceType>10</rasd:ResourceType> 
        <rasd:OtherResourceType>ovirtmgmt</rasd:OtherResourceType> 
        <rasd:ResourceSubType>3</rasd:ResourceSubType> 
        <rasd:Connection>ovirtmgmt</rasd:Connection> 
        <rasd:Linked>true</rasd:Linked> 
        <rasd:Name>nic1</rasd:Name> 
        <rasd:MACAddress>00:1a:4a:87:cb:00</rasd:MACAddress> 
        <rasd:speed>1000</rasd:speed> 
        <Type>interface</Type> 
        <Device>bridge</Device> 
        <rasd:Address>{slot=0x03, bus=0x00, domain=0x0000, type=pci, function=0x0}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>net0</Alias>
      </Item> 
      <Item> 
        <rasd:Caption>USB Controller</rasd:Caption> 
        <rasd:InstanceId>3</rasd:InstanceId> 
        <rasd:ResourceType>23</rasd:ResourceType> 
        <rasd:UsbPolicy>DISABLED</rasd:UsbPolicy>
      </Item> 
      <Item> 
        <rasd:Caption>Graphical Controller</rasd:Caption> 
        <rasd:InstanceId>17bbf0db-7cf0-4529-9b53-dee6dee41cfd</rasd:InstanceId> 
        <rasd:ResourceType>20</rasd:ResourceType> 
        <rasd:VirtualQuantity>1</rasd:VirtualQuantity> 
        <rasd:SinglePciQxl>false</rasd:SinglePciQxl> 
        <Type>video</Type> 
        <Device>qxl</Device> 
        <rasd:Address>{slot=0x02, bus=0x00, domain=0x0000, type=pci, function=0x0}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>true</IsReadOnly> 
        <Alias>video0</Alias> 
        <SpecParams>  
          <vram>32768</vram> 
          <heads>1</heads>
        </SpecParams>
      </Item> 
      <Item> 
        <rasd:Caption>CDROM</rasd:Caption> 
        <rasd:InstanceId>7ce1bd14-d98a-43ba-beee-520bdfd9c698</rasd:InstanceId> 
        <rasd:ResourceType>15</rasd:ResourceType> 
        <Type>disk</Type> 
        <Device>cdrom</Device> 
        <rasd:Address>{bus=1, controller=0, type=drive, target=0, unit=0}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>true</IsReadOnly> 
        <Alias>ide0-1-0</Alias></Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>8758c42f-7523-461b-82bb-41d91e46fd36</rasd:InstanceId> 
        <Type>controller</Type> 
        <Device>usb</Device> 
        <rasd:Address>{slot=0x01, bus=0x00, domain=0x0000, type=pci, function=0x2}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>usb0</Alias>
      </Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>58f1a596-553e-4e95-9331-64b5d8cebe2e</rasd:InstanceId> 
        <Type>controller</Type> 
        <Device>ide</Device> 
        <rasd:Address>{slot=0x01, bus=0x00, domain=0x0000, type=pci, function=0x1}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>ide0</Alias>
      </Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>2f4f8aa5-25eb-4a31-b841-50dc48fce4a7</rasd:InstanceId> 
        <Type>channel</Type> 
        <Device>unix</Device> 
        <rasd:Address>{bus=0, controller=0, type=virtio-serial, port=1}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>channel0</Alias>
      </Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>edaac3ed-2ab6-48b1-ae77-cc98f8b45bd8</rasd:InstanceId> 
        <Type>channel</Type> 
        <Device>unix</Device> 
        <rasd:Address>{bus=0, controller=0, type=virtio-serial, port=2}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>channel1</Alias>
      </Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>8dfed248-5164-41d3-8b6e-46aef9798d84</rasd:InstanceId> 
        <Type>channel</Type> 
        <Device>spicevmc</Device> 
        <rasd:Address>{bus=0, controller=0, type=virtio-serial, port=3}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>channel2</Alias>
      </Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>d184185e-ee19-442a-88f5-6a48f14164e1</rasd:InstanceId> 
        <Type>controller</Type> 
        <Device>virtio-scsi</Device> 
        <rasd:Address>{slot=0x04, bus=0x00, domain=0x0000, type=pci, function=0x0}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>scsi0</Alias>
      </Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>374d219e-e2ff-4755-a544-d537c87e82df</rasd:InstanceId> 
        <Type>controller</Type> 
        <Device>virtio-serial</Device> 
        <rasd:Address>{slot=0x05, bus=0x00, domain=0x0000, type=pci, function=0x0}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>false</IsReadOnly> 
        <Alias>virtio-serial0</Alias>
      </Item> 
      <Item> 
        <rasd:ResourceType>0</rasd:ResourceType> 
        <rasd:InstanceId>cf3d7121-9db0-4fd1-bd12-50ce4e1ce379</rasd:InstanceId> 
        <Type>balloon</Type> 
        <Device>memballoon</Device> 
        <rasd:Address>{slot=0x07, bus=0x00, domain=0x0000, type=pci, function=0x0}</rasd:Address> 
        <BootOrder>0</BootOrder> 
        <IsPlugged>true</IsPlugged> 
        <IsReadOnly>true</IsReadOnly> 
        <Alias>balloon0</Alias> 
        <SpecParams> 
          <model>virtio</model>
        </SpecParams>
      </Item>
    </Section>
  </Content>
</ovf:Envelope>
You can create a snapshot of a virtual machine that is running (a live snapshot) or shut down by using the POST method:

Example 15.41. Creating a Virtual Machine Snapshot

POST /ovirt-engine/api/vms/00000000-0000-0000-0000-000000000000/snapshots/ HTTP/1.1
Accept: application/xml
Content-type: application/xml

<snapshot>
<description>Snapshot description</description>
</snapshot>

Important

Before taking a live snapshot of a virtual machine that uses OpenStack Volume (Cinder) disks, you must freeze and thaw the guest filesystem manually. See Section 15.7.14, “Freeze Virtual Machine Filesystems Action” and Section 15.7.15, “Thaw Virtual Machine Filesystems Action” for more information.
You can restore a virtual machine snapshot using the rel="restore" action link in the snapshot representation:

Example 15.42. Restoring a Virtual Machine Snapshot

POST /ovirt-engine/api/vms/00000000-0000-0000-0000-000000000000/snapshots/00000000-0000-0000-0000-000000000000/restore HTTP/1.1
Accept: application/xml
Content-type: application/xml

<action/>

15.6.5.2. Clone a Virtual Machine from a Snapshot

API provides a function to create virtual machines from a snapshot of a previous machine. API users create a new virtual machine while retaining the original virtual machine with all snapshots intact.
Creation of a virtual machines from a snapshot requires an additional snapshots element to a standard representation of a virtual machine, which a user sends in a POST request to the vms collection.
The snapshots element contains a snapshot id= element to define the specific snapshot to use as a basis for the virtual machine.

Example 15.43. Clone Virtual Machine from Snapshot

POST /ovirt-engine/api/vms HTTP/1.1
Accept: application/xml
Content-type: application/xml

<vm>
  ...
  <snapshots>
    <snapshot id="3f68ee63-0016-4f8c-9b8a-11d9f28f7c9e"/>
  </snapshots>
  ...
</vm>

15.6.6. Statistics Sub-Collection

Each virtual machine resource exposes a statistics sub-collection for virtual machine-specific statistics. Each statistic contains the following elements:

Table 15.11. Elements for virtual machine statistics

Element Type Description
name string The unique identifier for the statistic entry.
description string A plain text description of the statistic.
unit string The unit or rate to measure the statistical values.
type One of GAUGE or COUNTER The type of statistic measures.
values type= One of INTEGER or DECIMAL The data type for the statistical values that follow.
value complex A data set that contains datum.
datum see values type An individual piece of data from a value.
vm id= relationship A relationship to the containing vm resource.
The following table lists the statistic types for virtual machines.

Table 15.12. Virtual machine statistic types

Name
Description
memory.installed
Total memory in bytes allocated for the virtual machine's use.
memory.used
Current memory in bytes used by the virtual machine.
cpu.current.guest
Percentage of CPU used by the guest.
cpu.current.hypervisor
Percentage of CPU overhead on the hypervisor.
cpu.current.total
Total percentage of the current CPU in use.

Example 15.44. An XML representation of a virtual machine's statistics sub-collection

<statistics>
    <statistic id="ef802239-b74a-329f-9955-be8fea6b50a4"
      href="/ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401/
      statistics/ef802239-b74a-329f-9955-be8fea6b50a4">
        <name>memory.installed</name>
        <description>Total memory configured</description>
        <unit>BYTES</unit>
        <type>GUAGE</type>
        <values type="DECIMAL">
            <value>
                <datum>1073741824<datum>
            </value>
        </values>
        <vm id="cdc0b102-fbfe-444a-b9cb-57d2af94f401"
          href="/ovirt-engine/api/vms/cdc0b102-fbfe-444a-b9cb-57d2af94f401"/>
    </statistic>
    ...
</statistics>

Note

A virtual machine's statistics sub-collection is read-only.

15.6.7. Displaying Virtual Machine Session Information

Submit a GET request for a virtual machine and use the session sub-collection to view the session information for the user that initiated the SPICE console session and the user logged in to the virtual machine.
The session information of a virtual machine is listed as a sub-collection:

Example 15.45. Displaying the session information of a virtual machine

GET /ovirt-engine/api/roles/a1a701f1-aa06-4f02-af17-158be31489b3/sessions HTTP/1.1
Accept: application/xml

HTTP/1.1 200 OK
Content-Type: application/xml

<sessions>
  <session id="37a6259c-c0c1-dae2-99a7-866489dff0bd"
    href= "/ovirt-engine/api/vms/a1a701f1-aa06-4f02-af17-158be31489b3/sessions/37a6259c-c0c1-dae2-99a7-866489dff0bd">
  <vm href= "/ovirt-engine/api/vms/a1a701f1-aa06-4f02-af17-158be31489b3" id="a1a701f1-aa06-4f02-af17-158be31489b3"/>
  <ip address="192.0.2.0"/>
  <user href= "/ovirt-engine/api/users/fdfc627c-d875-11e0-90f0-83df133b58cc" id="fdfc627c-d875-11e0-90f0-83df133b58cc">
    <domain href= "/ovirt-engine/api/domains/696e7465-726e-616c-696e-7465726e616c" id="696e7465-726e-616c-696e-7465726e616c">
      <name>internal</name>
    </domain>
    <user_name>admin</user_name>
    </user>
    <console_user>true</console_user>
  </session>
  <session id="37a6259c-c0c1-dae2-99a7-866489dff0bd"
    href= "/ovirt-engine/api/vms/a1a701f1-aa06-4f02-af17-158be31489b3/sessions/37a6259c-c0c1-dae2-99a7-866489dff0bd" >
    <vm href= "/ovirt-engine/api/vms/a1a701f1-aa06-4f02-af17-158be31489b3" id="a1a701f1-aa06-4f02-af17-158be31489b3"/>
    <user>
      <user_name>root</user_name>
    </user>
  </session>
</sessions>