Running Guest OS Operations

Guest OS operations manipulate processes, files, folders, and environment variables in a virtual machine's guest operating system.

The vSphere API offers the following managed object types for guest operations:

  • GuestAuthManager – authenticate to acquire credentials in the guest OS.
  • GuestFileManager – manipulate files, directories, and remote copying in the guest OS.
  • GuestProcessManager – manipulate processes in the guest OS.
  • GuestAliasManager – support single sign-on for guest operations; create and delete user aliases.
  • GuestWindowsRegistryManager – manipulate keys and values in the Windows registry.
  • VirtualMachineGuestCustomizationManager – customize guest settings, especially for instant clone virtual machines.

All the above managed objects are subclasses that inherit properties from GuestOperationsManager. In the vSphere API, the VirtualMachine and GuestInfo managed objects contain information about what guest operations might be running and relevant virtual machine state:

VMware Tools must be present to run guest operations. To perform interactive guest operations, the user must be logged into the console, for example through the vSphere Client. Steps involved are:
  1. Java or C# program translates to SOAP bindings.
  2. Directives of vSphere API pass through vCenter Server.
  3. Directives are relayed to ESXi host agent process.
  4. Virtual machine executable passes guest operations to VMware tools.
  5. Guest OS performs guest operations.
Figure 1. Guest operations control flow

The following table summarizes the methods available for guest operations.

Table 1. GuestOperationsManager methods
Managed Object Methods Description
GuestAliasManager AddGuestAlias define alias for guest account
ListGuestAliases list guest aliases for specified user
ListGuestMappedAliases list alias map for in-guest user
RemoveGuestAliasByCert remove certificate associated aliases
GuestAuthManager AcquireCredentialsInGuest authenticate, return session object
ReleaseCredentialsInGuest release session object
ValidateCredentialsInGuest check authentication data or timeout
GuestFileManager ChangeFileAttributesInGuest change attributes of file in guest
CreateTemporaryDirectoryInGuest make a temporary directory
CreateTemporaryFileInGuest create a temporary file
DeleteDirectoryInGuest remote directory in guest OS
DeleteFileInGuest remove file in guest OS
InitiateFileTransferFromGuest start file transfer from guest OS
InitiateFileTransferToGuest start file transfer to guest OS
ListFilesInGuest list files or directories in guest
MakeDirectoryInGuest make a directory in guest
MoveDirectoryInGuest move or rename a directory in guest
MoveFileInGuest rename a file in guest
GuestWindowsRegistryManager CreateRegistryKeyInGuest create a registry key
DeleteRegistryKeyInGuest delete a registry key
DeleteRegistryValueInGuest delete a registry value
ListRegistryKeysInGuest list registry subkeys for a given key
ListRegistryValuesInGuest list registry values for a given key
SetRegistryValueInGuest set or create a registry value
GuestProcessManager ListProcessesInGuest list processes running in guest OS
ReadEnvironmentVariableInGuest read environment variable in guest
StartProgramInGuest start running program in guest
TerminateProcessInGuest stop a running process in guest

InitiateFileTransferFromGuest and InitiateFileTransferToGuest are useful for transferring small files between the host and guest. For large file transfers, virtual machines should be connected to the network because networking transfers are much faster.

Java Source Code Samples

Four Java code samples based on JAX-WS are available in the vSphere SDK for Web services, in this directory:

SDK/vsphere-ws/java/JAXWS/samples/com/vmware/guest creates a temporary file inside a virtual machine, by calling the following method:

vimPort.createTemporaryFileInGuest(fileManagerRef, vmMOR, auth, prefix, suffix, directoryPath); downloads a file from the guest to a specified path on the host where the client is running. The destination, a local file on the client host, is specified on the command line as --localfilepath.

vimPort.initiateFileTransferFromGuest(fileManagerRef, vmMOR, auth, guestFilePath); runs a specified program inside a guest operating system, with output re‐directed to a temporary file, and downloads the resulting output to a file on the local client. The program must already exist on the guest, and is specified on the command line as --guestprogrampath. The output file to store on the client host is specified on the command line as --localoutputfilepath.

vimPort.startProgramInGuest(processManagerRef, vmMOR, auth, spec); uploads a file from the client machine to a specified location inside the guest. The source, a local file on the client host, is specified on the command line as --localfilepath.

vimPort.initiateFileTransferToGuest(fileManagerRef, vmMOR, auth, guestFilePath,
                          guestFileAttributes, fileSize, optionsmap.containsKey("overwrite"));