In order to be able to list VM Guests, you need to connect to a VM Host Server first. If you start the management tool on the VM Host Server itself, you are automatically connected. When operating from remote, refer to Section 7.3, “Connecting to a VM Host Server” for instructions.

# list running guests on localhost
virsh -c qemu:///system list
# list running + inactive guests on mercury over TLS connection
virsh -c qemu+tls://mercury.example.com/system list --all
# list running + inactive guests on mercury over SSH connection
virsh -c qemu+ssh://tux@mercury.example.com/system list --inactive

Opening a Graphical Console to a VM Guest lets you interact with the machine like a physical host via a VNC connection. If accessing the VNC server requires authentication, you are prompted to enter a user name (if applicable) and a password.

Once you click into the VNC console, the cursor is “grabbed” and cannot be used outside the console anymore. To release it, press Alt+Ctrl.

	Absolute Cursor Movement
In order to prevent the console from grabbing the cursor and to enable absolute (seamless) cursor movement, add a tablet input device to the VM Guest.

Certain key combinations such as Ctrl+Alt+Del are interpreted by the host system and are not passed to the VM Guest.

To pass such key combinations to a VM Guest, open the Send Key menu from the VNC window and choose the desired key combination entry.

	Supported VNC Viewer
Principally all VNC viewers are able to connect to the console of a VM Guest. However, if you are using SASL authentication and/or TLS/SSL connection to access the guest, the options become limited. Common VNC viewers such as tightvnc or tigervnc support neither SASL authentication or TSL/SSL. The only supported alternative to Virtual Machine Manager and virt-viewer is vinagre.

# local connect to guest with ID 8
virt-viewer -c qemu:///system 8

# local connect to the inactive guest sles11; will connect once
# the guest starts
virt-viewer --wait sles11
virt-viewer -c qemu:///system --wait sles11

# remote connect via ssh
viewer -c qemu+ssh://tux@mercury.example.com/system 8

# remote connect via ssh wait / reconnect mode:
virt-viewer -c qemu+ssh://root@mercury.example.com/system -w sles11

Starting, stopping or pausing a VM Guest can either be done with Virtual Machine Manager or virsh. You can also configure a VM Guest to be automatically started when booting the VM Host Server.

When shutting down a VM Guest, you may either shut it down gracefully, or force the shutdown. The latter is equivalent to pulling the power plug on a physical host and is only recommended if there are no alternatives. Forcing a shutdown may cause file system corruption and loss of data on the VM Guest.

Graceful Shutdown

In order to be able to perform a graceful shutdown, the VM Guest must be configured to support ACPI. If you have created the guest with vm-install or with Virtual Machine Manager, ACPI should be available. Use the following procedure in Virtual Machine Manager to check: Double-click the VM Guest entry in Virtual Machine Manager. Choose View+Details and then Overview+Machine Settings. ACPI should be checked. Depending on the guest operating system, enabling ACPI may not be sufficient. It is strongly recommended to test shutting down and rebooting a guest before releasing it to production. openSUSE or SUSE Linux Enterprise Desktop, for example, may require PolicyKit authorization for shutdown and reboot. Make sure this policy is turned off on all VM Guests. If ACPI was enabled during a Windows XP/Server 2003 guest installation, turning it on in the VM Guest configuration alone is not sufficient. See the following articles for more information: http://support.microsoft.com/kb/314088/EN-US/ http://support.microsoft.com/?kbid=309283 A graceful shutdown is of course always possible from within the guest operating system, regardless of the VM Guest's configuration.

virsh -c qemu:///system start sles11                # start
virsh -c qemu:///system suspend sles11              # pause
virsh -c qemu:///system reboot sles11               # reboot
virsh -c qemu:///system shutdown sles11             # graceful shutdown
virsh -c qemu:///system destroy sles11              # force shutdown
virsh -c qemu:///system autostart sles11            # turn on autostart
virsh -c qemu:///system autostart --disable sles11  # turn off autostart

Saving a VM Guest preserves the exact state of the guest’s memory. The operation is slightly similar to hibernating a computer. A saved VM Guest can be quickly restored to its previously saved running condition.

When saved, the VM Guest is paused, its current memory state saved to disk, and then the guest is stopped. The operation does not make a copy of any portion of the VM Guest’s virtual disk. The amount of time to save the virtual machine depends on the amount of memory allocated. When saved, a VM Guest’s memory is returned to the pool of memory available on the VM Host Server.

The restore operation loads a VM Guest’s previously saved memory state file and starts it. The guest is not booted but rather resumes at the point where it was previously saved. The operation is slightly similar to coming out of hibernation.

The VM Guest is saved to a state file. Make sure there is enough space on the partition you are going to save to. Issue the following command on the guest to get a rough estimation of the file size in megabytes to be expected:

free -m | awk '/^Mem:/ {print $3}'

After using the save operation, do not boot, start, or run the saved VM Guest. Doing so would cause the machine's virtual disk and the saved memory state getting out of sync and can result in critical errors when restoring the guest.

# save the guest named opensuse11
virsh save opensuse11 /virtual/saves/opensuse11.vmsave
   
# save the guest with Id 37
virsh save 37 /virtual/saves/opensuse11.vmsave

virsh restore /virtual/saves/opensuse11.vmsave

Deleting a VM Guest removes its XML configuration by default. Since the attached storage is not deleted, you will be able to use it with another VM Guest. With Virtual Machine Manager you may also delete a guest's storage files as well—this will completely erase the guest.

In order to delete a VM Guest, it has to be shut down first (refer to Section 6.3, “Changing a VM Guest's State: Start, Stop, Pause” for instructions). It is not possible to delete a running guest.