Product Documentation

Change VM Properties

Jul 01, 2013

Select a virtual machine in the Resources pane and click on the General tab to see its properties. You can change many of these properties from the VM's Properties dialog box: click the Properties button in the upper right corner of the General tab.

General properties - Name, Description, Folder, Tags

On the General Properties tab you can change the VM's name and description, place it in a folder, and manage its tags.

  • To change the VM name, enter a new name in the Name box.
  • To change the VM description, enter new text in the Description box.
  • To place the VM in a folder or to move it to a different folder, click Change in the Folder box and select a folder. See Using folders for more information about using folders.
  • To tag and untag the VM and to create and delete tags, see Using tags.

Custom fields

Custom fields allow you to add information to managed resources to make it easier to search and organize them. See Using custom fields to find out how to assign custom fields to your managed resources.


On the CPU tab, you can adjust the number of virtual CPUs allocated to the VM and set the VCPU priority. You can configure up to 8 virtual CPUs on a VM. To ensure you get the best performance out of your VM, the number of VCPUs must not be more than the number of physical CPUs on its host server. VCPU priority is the priority given to each CPU during CPU scheduling, relative to all the other VMs running on the host server.

To change the number of virtual CPUs, change the number in the Number of VCPUs box.

To tune the VCPU priority, move the VCPU slider.

The XenServer templates provide typical VM configurations and set reasonable defaults for the memory, based on the type of guest operating system. You should also take into account the following considerations when deciding how much memory you give to a VM:

  • The kinds of applications that will run on the VM.
  • Other virtual machines that will be using the same memory resource.
  • Applications that will run on the server alongside the virtual machine.

Boot Options

The available boot options on this tab may vary, depending on the guest operating system. For example, on some VMs, you can change the boot order (or boot sequence), or specify additional boot parameters.

  • To change the boot order, select an item in the Boot Order list and click Move Up or Move Down.
  • To specify additional boot parameters, enter them in the OS Boot parameters box. For example, on a Debian VM, you can enter single to boot the VM in single-user mode.

Start Options

On this tab you can adjust the start order, start delay interval and HA restart priority for the selected VM.

Value Description
Start order Specifies the order in which individual VMs will be started up within a vApp or during an HA recovery operation, allowing certain VMs to be started before others. VMs with a start order value of 0 (zero) will be started first, then VMs with a start order value of 1, followed by VMs with a start order value of 2, and so on.
Attempt to start next VM after This is a delay interval that specifies how long to wait after starting the VM before attempting to start the next group of VMs in the startup sequence, that is, VMs with a lower start order. This applies to VMs within a vApp and to individual VMs during an HA recovery operation.
HA restart priority In an HA-enabled pool, this specifies which VMs will be restarted automatically in the event of an underlying hardware failure or loss of their host server.
  • VMs with an HA restart priority of Restart are guaranteed to be restarted if sufficient resources are available within the pool. They will be restarted before VMs with a Restart if possible priority.
  • VMs with an HA restart priority of Restart if possible are not considered when calculating a failure plan, but one attempt to restart them will be made if a server that is running them fails. This restart is attempted after all higher-priority VMs are restarted, and if the attempt to start them fails, then it will not be retried.
  • VMs with an HA restart priority of Do not restart will not be restarted automatically.

See VM startup settings for more information about these settings.


On the Alerts tab, you can configure performance alerts for the VM's CPU usage, network, and disk activity.

For information about configuring alerts, see Configuring performance alerts.

Home Server

On the Home Server tab of the VM Properties dialog box you can nominate a server which will provide resources for the VM. The VM will be started up on that server if possible; if this is not possible, then an alternate server within the same pool will be selected automatically. See Creating a new VM to find out more about home servers.

Note that in pools with Workload Balancing (WLB) enabled, you cannot set a home server. Instead, XenCenter nominates the best server for the VM by analyzing XenServer resource pool metrics and recommending optimizations. You can decide if you want these recommendations geared towards resource performance or hardware density, and you can fine-tune the weighting of individual resource metrics (CPU, network, memory, and disk) so that the placement recommendations and critical thresholds align with your environment's needs.

GPU (Windows VMs only)

On the VM's GPU properties tab, you can assign a dedicated graphics processing unit (GPU) to a Windows VM, providing direct access to the graphic hardware from the VM. The GPU pass-through feature allows a VM to use the full processing power of the GPU, providing better support for high-end 3D professional graphics applications such as CAD/CAM, GIS and Medical Imaging applications.

To enable GPU passthrough, select a GPU from the GPU type list, which lists GPUs available in the current pool.

Advanced Options (Optimization)

On the Advanced Options tab, you can adjust the amount of shadow memory assigned to a hardware-assisted VM. In some specialized application workloads, such as Citrix XenApp, extra shadow memory is required to achieve full performance. This memory is considered to be overhead, and is separate from the normal memory calculations for accounting memory to a VM.

  • To optimize performance for VMs running Citrix XenApp, click Optimize for Citrix XenApp.
  • To manually adjust the VM's shadow memory allocation, click Optimize manually and enter a number in the Shadow memory multiplier box.
  • To restore the default settings for shadow memory, select the Optimize for general use option.