Configuring Asset Management › Collect Tasks › Configuring the Collect Task to Control Content Distribution › Waking Virtual Machines (Virtual WOL) › How Client Automation Wakes a Virtual Machine

How Client Automation Wakes a Virtual Machine

The method for waking a virtual machine differs from the method that is used to wake a physical computer. Each platform virtualization vendor provides their own SDK for WOL operations. As the AM remote agent already uses these SDKs to collect inventory, the agent can perform virtual WOLs using the new generic SendWOL method. Client Automation uses the following process to wake virtual machines.

• When a virtual machine registers with the DSM domain manager, the domain manager does not initially know that it is a virtual machine. The WOL protocol type is changed from "nw" to "vm" only when the AM remote agent next runs and sends the required relationship information between the virtual machine and its host. This action also disables WOL on the virtual machine (the default setting for virtual machines).
• The AM remote agent gathers the following inventory information about VMs from their virtualization servers and reports this information to the DSM domain manager and MDB:

  Note: The RVI agent cannot collect certain BIOS inventory attributes from Linux virtual machines that are running on Microsoft Hyper-V and XenServer servers, Virtual WOL is not supported on such Linux virtual machines.

  • FQDN of the parent virtualization server of the VM for waking up.
  • Platform virtualization type (VMware ESXi, Microsoft Hyper-V, and so on)
  • Login credentials for the virtualization server
  • Vendor-specific identifying string for the VM

    Note: Typically, the string is a virtual GUID but it could be a system ID or serial number.

• The AM remote agent stores this information in a simple flat file named rvidb.txt under the folder CA\DSM\Agent\units\00000001\uam\rvi. This file can be accessed to add and retrieve information about a virtualization server given its URL. To avoid unlimited growth of this file, all aged virtualization servers and their respective lists of VMs are deleted automatically after one year.
• When the domain manager receives a vWOL request, it delegates the request to a scalability server. The scalability server in turn delegates it to the AM remote agent computer. The AM remote agent computer then wakes the virtual machine.