Managing Virtual Machines Instances

This guide follows the Creating Virtual Machines guide. Once a Template is instantiated to a Virtual Machine, there are a number of operations that can be performed using the onevm command.

Virtual Machine Life-cycle

The life-cycle of a Virtual Machine within OpenNebula includes the following stages:


Note that this is a simplified version. If you are a developer you may want to take a look at the complete diagram referenced in the Virtual Machines States Reference guide):

Short state State Meaning
pend Pending By default a VM starts in the pending state, waiting for a resource to run on. It will stay in this state until the scheduler decides to deploy it, or the user deploys it using the onevm deploy command.
hold Hold The owner has held the VM and it will not be scheduled until it is released. It can be, however, deployed manually.
clon Cloning The VM is waiting for one or more disk images to finish the initial copy to the repository (image state still in lock)
prol Prolog The system is transferring the VM files (disk images and the recovery file) to the host in which the virtual machine will be running.
boot Boot OpenNebula is waiting for the hypervisor to create the VM.
runn Running The VM is running (note that this stage includes the internal virtualized machine booting and shutting down phases). In this state, the virtualization driver will periodically monitor it.
migr Migrate The VM is migrating from one resource to another. This can be a life migration or cold migration (the VM is saved, powered-off or powered-off hard and VM files are transferred to the new resource).
hotp Hotplug A disk attach/detach, nic attach/detach operation is in process.
snap Snapshot A system snapshot is being taken.
save Save The system is saving the VM files after a migration, stop or suspend operation.
epil Epilog In this phase the system cleans up the Host used to virtualize the VM, and additionally disk images to be saved are copied back to the system datastore.
shut Shutdown OpenNebula has sent the VM the shutdown ACPI signal, and is waiting for it to complete the shutdown process. If after a timeout period the VM does not disappear, OpenNebula will assume that the guest OS ignored the ACPI signal and the VM state will be changed to running, instead of done.
stop Stopped The VM is stopped. VM state has been saved and it has been transferred back along with the disk images to the system datastore.
susp Suspended Same as stopped, but the files are left in the host to later resume the VM there (i.e. there is no need to re-schedule the VM).
poff PowerOff

Same as suspended, but no checkpoint file is generated. Note that the files are left in the host to later boot the VM there.

When the VM guest is shutdown, OpenNebula will put the VM in this state.

unde Undeployed The VM is shut down. The VM disks are transfered to the system datastore. The VM can be resumed later.
fail Failed The VM failed.
unkn Unknown The VM couldn’t be reached, it is in an unknown state.
clea Cleanup-resubmit The VM is waiting for the drivers to clean the host after a onevm recover --recreate action
done Done The VM is done. VMs in this state won’t be shown with onevm list but are kept in the database for accounting purposes. You can still get their information with the onevm show command.

Virtual Machine States

Managing Virtual Machines

The following sections show the basics of the onevm command with simple usage examples. A complete reference for these commands can be found here.

Create and List Existing VMs


Read the Creating Virtual Machines guide for more information on how to manage and instantiate VM Templates.


Read the complete reference for Virtual Machine templates.


Assuming we have a VM Template registered called vm-example with ID 6, then we can instantiate the VM issuing a:

onetemplate list
  ID USER     GROUP    NAME                         REGTIME
   6 oneadmin oneadmin vm_example            09/28 06:44:07
onetemplate instantiate vm-example --name my_vm
VM ID: 0

If the template has USER INPUTS defined the CLI will prompt the user for these values:

onetemplate instantiate vm-example --name my_vm
There are some parameters that require user input.
  * (BLOG_TITLE) Blog Title: <my_title>
  * (DB_PASSWORD) Database Password:
VM ID: 0

Afterwards, the VM can be listed with the onevm list command. You can also use the onevm top command to list VMs continuously.

onevm list
    ID USER     GROUP    NAME         STAT CPU     MEM        HOSTNAME        TIME
     0 oneadmin oneadmin my_vm        pend   0      0K                 00 00:00:03

After a Scheduling cycle, the VM will be automatically deployed. But the deployment can also be forced by oneadmin using onevm deploy:

onehost list
  ID NAME               RVM   TCPU   FCPU   ACPU   TMEM   FMEM   AMEM   STAT
   2 testbed              0    800    800    800    16G    16G    16G     on
onevm deploy 0 2
onevm list
    ID USER     GROUP    NAME         STAT CPU     MEM        HOSTNAME        TIME
     0 oneadmin oneadmin my_vm        runn   0      0K         testbed 00 00:02:40

and details about it can be obtained with show:

onevm show 0
ID                  : 0
NAME                : my_vm
USER                : oneadmin
GROUP               : oneadmin
STATE               : ACTIVE
START TIME          : 04/14 09:00:24
END TIME            : -
DEPLOY ID:          : one-0

OWNER          : um-
GROUP          : ---
OTHER          : ---

NET_TX              : 13.05
NET_RX              : 0
USED MEMORY         : 512
USED CPU            : 0


 SEQ        HOSTNAME REASON           START        TIME       PTIME
   0         testbed   none  09/28 06:48:18 00 00:07:23 00 00:00:00

Searching VM Instances...

You can search for VM instances by using the --search option of the onevm list command. This is specially usefull on large environments with many VMs. The filter must be in a KEY=VALUE format and will return all the VMs which fit the filter.

The KEY must be in the VM template section or be one of the following:

  • NAME

For example, for searching a VM with a specific MAC addres:

onevm list --search MAC=02:00:0c:00:4c:dd
 21005 oneadmin oneadmin test-vm pend    0   0K      1d 23h11

Equivalently if there are more than one VM instance that matches the result they will be shown. for example, VMs with a given NAME:

onevm list --search NAME=test-vm
 21005 oneadmin oneadmin test-vm pend    0   0K       1d 23h13
 2100  oneadmin oneadmin test-vm pend    0   0K      12d 17h59


This feature is only available for MySQL backend with a version higher or equal than 5.6.

Terminating VM Instances...

You can terminate an instance with the onevm terminate command, from any state. It will shutdown (if needed) and delete the VM. This operation will free the resources (images, networks, etc) used by the VM.

If the instance is running, there is a --hard option that has the following meaning:

  • terminate: Gracefully shuts down and deletes a running VM, sending the ACPI signal. Once the VM is shutdown the host is cleaned, and persistent and deferred-snapshot disk will be moved to the associated datastore. If after a given time the VM is still running (e.g. guest ignoring ACPI signals), OpenNebula will returned the VM to the RUNNING state.
  • terminate --hard: Same as above but the VM is immediately destroyed. Use this action instead of terminate when the VM doesn’t have ACPI support.

Pausing VM Instances...

There are two different ways to temporarily stop the execution of a VM: short and long term pauses. A short term pause keeps all the VM resources allocated to the hosts so its resume its operation in the same hosts quickly. Use the following onevm commands or Sunstone actions:

  • suspend: the VM state is saved in the running Host. When a suspended VM is resumed, it is immediately deployed in the same Host by restoring its saved state.
  • poweroff: Gracefully powers off a running VM by sending the ACPI signal. It is similar to suspend but without saving the VM state. When the VM is resumed it will boot immediately in the same Host.
  • poweroff --hard: Same as above but the VM is immediately powered off. Use this action when the VM doesn’t have ACPI support.


When the guest is shutdown from within the VM, OpenNebula will put the VM in the poweroff state.

You can also plan a long term pause. The Host resources used by the VM are freed and the Host is cleaned. Any needed disk is saved in the system datastore. The following actions are useful if you want to preserve network and storage allocations (e.g. IPs, persistent disk images):

  • undeploy: Gracefully shuts down a running VM, sending the ACPI signal. The Virtual Machine disks are transferred back to the system datastore. When an undeployed VM is resumed, it is be moved to the pending state, and the scheduler will choose where to re-deploy it.
  • undeploy --hard: Same as above but the running VM is immediately destroyed.
  • stop: Same as undeploy but also the VM state is saved to later resume it.

When the VM is successfully paused you can resume its execution with:

  • resume: Resumes the execution of VMs in the stopped, suspended, undeployed and poweroff states.

Rebooting VM Instances...

Use the following commands to reboot a VM:

  • reboot: Gracefully reboots a running VM, sending the ACPI signal.
  • reboot --hard: Performs a ‘hard’ reboot.

Delaying VM Instances...

The deployment of a PENDING VM (e.g. after creating or resuming it) can be delayed with:

  • hold: Sets the VM to hold state. The scheduler will not deploy VMs in the hold state. Please note that VMs can be created directly on hold, using ‘onetemplate instantiate –hold’ or ‘onevm create –hold’.

Then you can resume it with:

  • release: Releases a VM from hold state, setting it to pending. Note that you can automatically release a VM by scheduling the operation as explained below

Disk Snapshots

There are two kinds of operations related to disk snapshots:

  • disk-snapshot-create, disk-snapshot-revert, disk-snapshot-delete, disk-snapshot-rename: Allows the user to take snapshots of the disk states and return to them during the VM life-cycle. It is also possible to rename or delete snapshots.
  • disk-saveas: Exports VM disk (or a previously created snapshot) to an image. This is a live action.


Disk Snapshots are not supported in vCenter

Managing Disk Snapshots

A user can take snapshots of the disk states at any moment in time (if the VM is in RUNNING, POWEROFF or SUSPENDED states). These snapshots are organized in a tree-like structure, meaning that every snapshot has a parent, except for the first snapshot whose parent is -1. At any given time a user can revert the disk state to a previously taken snapshot. The active snapshot, the one the user has last reverted to, or taken, will act as the parent of the next snapshot. In addition, it’s possible to delete snapshots that are not active and that have no children.


The default behavior described previously can be overridden by the storage driver; and it may allow a flat snapshot structure without parent/child relationship. In that case, snapshots can be freely removed.

  • disk-snapshot-create <vmid> <diskid> <name>: Creates a new snapshot of the specified disk.
  • disk-snapshot-revert <vmid> <diskid> <snapshot_id>: Reverts to the specified snapshot. The snapshots are immutable, therefore the user can revert to the same snapshot as many times as he wants, the disk will return always to the state of the snapshot at the time it was taken.
  • disk-snapshot-delete <vmid> <diskid> <snapshot_id>: Deletes a snapshot if it has no children and is not active.


disk-snapshot-create can take place when the VM is in RUNNING state, provided that the drivers support it, while disk-snapshot-revert requires the VM to be POWEROFF or SUSPENDED. Live snapshots are only supported for some drivers:

  • Hypervisor VM_MAD=kvm combined with TM_MAD=qcow2 datastores. In this case OpenNebula will request that the hypervisor executes virsh snapshot-create.
  • Hypervisor VM_MAD=kvm with Ceph datastores (TM_MAD=ceph). In this case OpenNebula will initially create the snapshots as Ceph snapshots in the current volume.

With CEPH and qcow2 datastores and KVM hypervisor you can enable QEMU Guest Agent. With this agent enabled the filesystem will be frozen while the snapshot is being done.

OpenNebula will not automatically handle non-live disk-snapshot-create and disk-snapshot-revert operations for VMs in RUNNING if the drivers do not support it. In this case the user needs to suspend or poweroff the VM before creating the snapshot.

See the Storage Driver guide for a reference on the driver actions invoked to perform live and non-live snapshost.

Persistent Image Snapshots

These actions are available for both persistent and non-persistent images. In the case of persistent images the snapshots will be preserved upon VM termination and will be able to be used by other VMs using that image. See the snapshots section in the Images guide for more information.

Back-end Implementations

The snapshot operations are implemented differently depending on the storage back-end:

Operation/TM_MAD Ceph Shared and SSH Qcow2 Dev, FS_LVM, LVM
Snap Create Creates a protected snapshot Copies the file. Creates a new qcow2 image with the previous disk as the backing file. Not Supported
Snap Create (live) Creates a protected snapshot and quiesces the guest fs. Not Supported (For KVM only) Launches virsh snapshot-create. Not Supported
Snap Revert Overwrites the active disk by creating a new snapshot of an existing protected snapshot Overwrites the file with a previously copied one. Creates a new qcow2 image with the selected snapshot as the backing file. Not Supported
Snap Delete Deletes a protected snapshot Deletes the file. Deletes the selected qcow2 snapshot. Not Supported


Depending on the DISK/CACHE attribute the live snapshot may or may not work correctly. To be sure, you can use CACHE=writethrough, although this delivers the slowest performance.

Exporting Disk Images with disk-saveas

Any VM disk can be exported to a new image (if the VM is in RUNNING, POWEROFF or SUSPENDED states). This is a live operation that happens immediately. This operation accepts --snapshot <snapshot_id> as an optional argument, which specifies a disk snapshot to use as the source of the clone, instead of the current disk state (value by default).


This action is not in sync with the hypervisor. If the VM is in RUNNING state make sure the disk is unmounted (preferred), synced or quiesced in some way or another before taking the snapshot.


In vCenter, the save as operation can only be performed when the VM is in POWEROFF state. Performing this action in a different state won’t work as vCenter cannot unlock the VMDK file.

Disk Hot-plugging

New disks can be hot-plugged to running VMs with the onevm disk-attach and disk-detach commands. For example, to attach to a running VM the Image named storage:

onevm disk-attach one-5 --image storage

To detach a disk from a running VM, find the disk ID of the Image you want to detach using the onevm show command, and then simply execute onevm detach vm_id disk_id:

onevm show one-5
onevm disk-detach one-5 1


NIC Hot-plugging

You can hot-plug network interfaces to VMs in the RUNNING, POWEROFF or SUSPENDED states. Simply specify the network where the new interface should be attached to, for example:

onevm show 2

ID                  : 2
NAME                : centos-server
STATE               : ACTIVE


ID NETWORK      VLAN BRIDGE   IP              MAC
 0 net_172        no vbr0    02:00:ac:10:0

onevm nic-attach 2 --network net_172

After the operation you should see two NICs, 0 and 1:

onevm show 2
ID                  : 2
NAME                : centos-server
STATE               : ACTIVE


ID NETWORK      VLAN BRIDGE   IP              MAC
 0 net_172        no vbr0    02:00:ac:10:00:c9
 1 net_172        no vbr0    02:00:ac:10:00:ca

You can also detach a NIC by its ID. If you want to detach interface 1 (MAC 02:00:ac:10:00:ca), execute:

onevm nic-detach 2 1



You can create, delete and restore snapshots for running VMs. A snapshot will contain the current disks and memory state.

onevm snapshot-create 4 "just in case"
onevm show 4
  ID         TIME NAME                                           HYPERVISOR_ID
   0  02/21 16:05 just in case                                   onesnap-0
onevm snapshot-revert 4 0 --verbose
VM 4: snapshot reverted


For KVM only. Please take into consideration the following limitations:

  • The snapshots are lost if any life-cycle operation is performed, e.g. a suspend, migrate, delete request.
  • Snapshots are only available if all the VM disks use the qcow2 driver.


Resizing VM Capacity

You may resize the capacity assigned to a Virtual Machine in terms of the virtual CPUs, memory and CPU allocated. VM resizing can be done in any of the following states: POWEROFF, UNDEPLOYED.

If you have created a Virtual Machine and you need more resources, the following procedure is recommended:

  • Perform any operation needed to prepare your Virtual Machine for shutting down, e.g. you may want to manually stop some services
  • Poweroff the Virtual Machine
  • Resize the VM
  • Resume the Virtual Machine using the new capacity

Note that using this procedure the VM will preserve any resource assigned by OpenNebula, such as IP leases.

The following is an example of the previous procedure from the command line:

onevm poweroff web_vm
onevm resize web_vm --memory 2G --vcpu 2
onevm resume web_vm

From Sunstone:


Resizing VM Disks

If the disks assigned to a Virtual Machine need more size, this can achieved at instantiation time of the VM. The SIZE parameter of the disk can be adjusted and, if it is bigger than the original size of the image, OpenNebula will:

  • Increase the size of the disk container prior to launching the VM
  • Using the contextualization packages, at boot time the VM will grow the filesystem to adjust to the new size. This is only available for Linux guests in KVM and vCenter.

This can be done with an extra file given to the instantiate command:

cat /tmp/disk.txt
DISK = [ IMAGE_ID = 4,
         SIZE = 2000]   # If Image 4 is 1 GB, OpenNebula will resize it to 2 GB
onetemplate instantiate 7 /tmp/disk.txt

Or with CLI options:

onetemplate instantiate <template> --disk image0:size=20000

This can also be achieved from Sunstone, both in Cloud and Admin View, at the time of instantiating a VM Template:



In vCenter a disk can be resized only if the VM is in poweroff state and the VM has no snapshots or the template, which the VM is based on, doesn’t use linked clones.

Updating VM Configuration

Some of the VM configuration attributes defined in the VM Template can be updated after the VM is created. If the VM is not running, the onevm updateconf command will allow you to change the following attributes:

Attribute Sub-attributes
CONTEXT Any value. Variable substitution will be made


Visit the Virtual Machine Template reference for a complete description of each attribute

In Sunstone this action is inside the ‘Conf’ VM panel:



Cloning a VM

A VM Template or VM instance can be copied to a new VM Template. This copy will preserve the changes made to the VM disks after the instance is terminated. The template is private, and will only be listed to the owner user.

There are two ways to create a persistent private copy of a VM:

  • Instantiate a template ‘to persistent’
  • Save a existing VM instance with onevm save

Instantiate to persistent

When instantiating to persistent the Template is cloned recursively (a private persistent clone of each disk Image is created), and that new Template is instantiated.

To “instantiate to persistent” use the --persistent option:

onetemplate instantiate web_vm --persistent --name my_vm
VM ID: 31
onetemplate list
  ID USER            GROUP           NAME                                REGTIME
   7 oneadmin        oneadmin        web_vm                       05/12 14:53:11
   8 oneadmin        oneadmin        my_vm                        05/12 14:53:38
oneimage list
   7 oneadmin   oneadmin   web-img         default       200M OS   Yes used    1
   8 oneadmin   oneadmin   my_vm-disk-0    default       200M OS   Yes used    1

In sunstone, activate the “Persistent” switch next to the create button:


Please bear in mind the following ontemplate instantiate --persistent limitation:

  • Volatile disks cannot be persistent, and the contents will be lost when the VM is terminated. The cloned VM Template will contain the definition for an empty volatile disk.

Save a VM Instance

Alternatively, a VM that was not created as persistent can be saved before it is destroyed. To do so, the user has to poweroff the VM first and then use the save operation.

This action clones the VM source Template, replacing the disks with snapshots of the current disks (see the disk-snapshot action). If the VM instance was resized, the current capacity is also used. The new cloned Images can be made persistent with the --persistent option. NIC interfaces are also overwritten with the ones from the VM instance, to preserve any attach/detach action.

onevm save web_vm copy_of_web_vm --persistent
Template ID: 26

In the Cloud View:


From the Admin View:


Please bear in mind the following onevm save limitations:

  • The VM’s source Template will be used. If this Template was updated since the VM was instantiated, the new contents will be used.
  • Volatile disks cannot be saved, and the current contents will be lost. The cloned VM Template will contain the definition for an empty volatile disk.
  • Disks and NICs will only contain the target Image/Network ID. If your Template requires extra configuration (such as DISK/DEV_PREFIX), you will need to update the new Template.

Scheduled Actions

We have two types of schedule actions, punctual and relative actions. Punctual actions can also be periodic.

One-Time Punctual Actions

Most of the onevm commands accept the --schedule option, allowing users to delay the actions until the given date and time.

Here is an usage example:

onevm suspend 0 --schedule "09/20"
VM 0: suspend scheduled at 2016-09-20 00:00:00 +0200
onevm resume 0 --schedule "09/23 14:15"
VM 0: resume scheduled at 2016-09-23 14:15:00 +0200
onevm show 0
ID                  : 0
NAME                : one-0


ID ACTION             SCHEDULED                  REP                  END         DONE MESSAGE
 0 suspend     09/20 00:00                                                                                                                                                                                                   -
 1 resume      09/23 14:15                                                                                                                                                                                                   -

These actions can be deleted or edited using the onevm update command. The time attributes use Unix time internally.

onevm update 0

  TIME="1379628000" ]
  TIME="1379938500" ]

Periodic Punctual Actions

To schedule periodic actions also use the option –schedule. However this command also needs more options to define the periodicity of the action.

  • --weekly: defines a weekly periodicity, so, the action will be execute all weeks, the days that the user defines.
  • --monthly: defines a monthly periodicity, so, the action will be execute all months, the days that the user defines.
  • --yearly: defines a yearly periodicity, so, the action will be execute all year, the days that the user defines.
  • --hourly: defines a hourly periodicity, so, the action will be execute each ‘x’ hours.
  • --end: defines when you want that the relative action finishes.

The option --weekly, --monthly and --yearly need the number of the days that the users wants execute the action.

  • --weekly: days separate with commas between 0 and 6. [0,6]
  • --monthly: days separate with commas between 1 and 31. [0,31]
  • --weekly: days separate with commas between 0 and 365. [0,365]

The option --hourly needs a number with the number of hours. [0,168] (1 week)

The option --end can be a number or a date:

  • Number: defines the number of repetitions.
  • Date: defines the date that the user wants to finished the action.

Here is an usage example:

onevm suspend 0 --schedule "09/20" --weekly "1,5" --end 5
VM 0: suspend scheduled at 2018-09-20 00:00:00 +0200
onevm resume 0 --schedule "09/23 14:15" --weekly "2,6" --end 5
VM 0: resume scheduled at 2018-09-23 14:15:00 +0200

            $ onevm snapshot-create 0 --schedule "09/23" --hourly 10 --end "12/25"
VM 0: resume scheduled at 2018-09-23 14:15:00 +0200
onevm show 0
ID                  : 0
NAME                : one-0


ID ACTION             SCHEDULED                  REP                  END         DONE MESSAGE
             0 suspend          09/23 00:00           Weekly 1,5        After 5 times            -
             1 resume           09/23 00:00           Weekly 2,6        After 5 times            -
             2 snapshot-create  09/23 00:00         Each 5 hours            On 12/25/18            -

These actions can be deleted or edited using the onevm update command. The time attributes use Unix time internally.

onevm update 0

    TIME="1537653600" ]
    TIME="1537653600" ]
    TIME="1537653600" ]

Relative Actions

Scheduled actions can be also relative to the Start Time of the VM. That is, it can be set on a VM Template, and apply to the number of seconds after the VM is instantiated.

For instance, a VM Template with the following SCHED_ACTION will spawn VMs that will automatically shutdown after 1 hour of being instantiated.

onetemplate update 0

   TIME="+3600" ]

This functionality is present graphically in Sunstone in the VM Template creation and update dialog, and in the VM Actions tab:


These are the commands that can be scheduled:

  • terminate [--hard]
  • undeploy [--hard]
  • hold
  • release
  • stop
  • suspend
  • resume
  • delete
  • delete-recreate
  • reboot [--hard]
  • poweroff [--hard]
  • snapshot-create

User Defined Data

Custom attributes can be added to a VM to store metadata related to this specific VM instance. To add custom attributes simply use the onevm update command.

onevm show 0

onevm update 0
onevm show 0



Manage VM Permissions

OpenNebula comes with an advanced ACL rules permission mechanism intended for administrators, but each VM object has also implicit permissions that can be managed by the VM owner. To share a VM instance with other users, to allow them to list and show its information, use the onevm chmod command:

onevm show 0
OWNER          : um-
GROUP          : ---
OTHER          : ---
onevm chmod 0 640
onevm show 0
OWNER          : um-
GROUP          : u--
OTHER          : ---

Administrators can also change the VM’s group and owner with the chgrp and chown commands.

Life-Cycle Operations for Administrators

There are some onevm commands operations meant for the cloud administrators:


  • resched: Sets the reschedule flag for the VM. The Scheduler will migrate (or migrate –live, depending on the Scheduler configuration) the VM in the next monitorization cycle to a Host that better matches the requirements and rank restrictions. Read more in the Scheduler documentation.
  • unresched: Clears the reschedule flag for the VM, canceling the rescheduling operation.


  • deploy: Starts an existing VM in a specific Host.
  • migrate --live: The Virtual Machine is transferred between Hosts with no noticeable downtime. This action requires a shared file system storage.
  • migrate: The VM gets stopped and resumed in the target host. In an infrastructure with multiple system datastores, the VM storage can be also migrated (the datastore id can be specified).

Note: By default, the above operations do not check the target host capacity. You can use the --enforce option to be sure that the host capacity is not overcommitted.


  • recover: If the VM is stuck in any other state (or the boot operation does not work), you can recover the VM with the following options. Read the Virtual Machine Failures guide for more information.
    • --success: simulates the success of the missing driver action
    • --failure: simulates the failure of the missing driver action
    • --retry: retries to perform the current driver action. Optionally the --interactive can be combined if its a Transfer Manager problem.
    • --delete: Deletes the VM, moving it to the DONE state immediately
    • --recreate: Deletes the VM, and moves it to the PENDING state
  • migrate or resched: A VM in the UNKNOWN state can be booted in a different host manually (migrate) or automatically by the scheduler (resched). This action must be performed only if the storage is shared, or manually transfered by the administrator. OpenNebula will not perform any action on the storage for this migration.

VNC/Spice Access through Sunstone

If the VM supports VNC or Spice and is running, then the VNC icon on the Virtual Machines view should be visible and clickable:



The Sunstone documentation contains a section on VNC troubleshooting.

Information for Developers and Integrators

  • Although the default way to create a VM instance is to register a Template and then instantiate it, VMs can be created directly from a template file using the onevm create command.
  • When a VM reaches the done state, it disappears from the onevm list output, but the VM is still in the database and can be retrieved with the onevm show command.
  • OpenNebula comes with an accounting tool that reports resource usage data.
  • The monitoring information, shown with nice graphs in Sunstone, can be retrieved using the XML-RPC methods one.vm.monitoring and one.vmpool.monitoring.