Virtual Disk API Programming Guide - Documentation - VMware

Initialize the Library
Virtual Disk API Functions
VixDiskLib_Init() initializes the old virtual disk library. The arguments majorVersion and minorVersion
represent the VDDK library’s release number and dot‐release number. The third, fourth, and fifth arguments
specify log, warning, and panic handlers. DLLs and shared objects are located in libDir.
VixError vixError = VixDiskLib_Init(majorVer, minorVer, &logFunc, &warnFunc, &panicFunc, libDir);
You should call VixDiskLib_Init() only once per process because of internationalization restrictions, at the
beginning of your program. You should call VixDiskLib_Exit() at the end of your program for cleanup. For
multithreaded programs you should write your own logFunc because the default function is not thread safe.
In most cases you should replace VixDiskLib_Init() with VixDiskLib_InitEx(), which allows you to
specify a configuration file. For information about InitEx, see “Initialize Virtual Disk API” on page 35.
Connect to a Workstation or Server
VixDiskLib_Connect() connects the library to either a local VMware host or a remote server. For hosted disk
on the local system, provide null values for most connection parameters. For managed disk on an ESX/ESXi
host, specify virtual machine name, ESX/ESXi host name, user name, password, and possibly port.
vixError = VixDiskLib_Connect(&cnxParams, &srcConnection)
You can opt to use the VixDiskLibSSPICreds connection parameter to enable Security Support Provider
Interface (SSPI) authentication. SSPI provides the advantage of not storing passwords in configuration files in
plain text or in the registry. In order to be able to use SSPI, the following conditions must be met:
Connections must be made directly to a vSphere Server or a VirtualCenter Server version 2.5 or later.
Applications and their connections must employ one of two user account arrangements. The connection
must be established either:
Using the same user context with the same user name and password credentials on both the proxy
and the vSphere Server or
Using a domain user. Attempts by applications to establish connections using the Local System
account context will fail.
User contexts must have administrator privileges on the proxy and have the VCB Backup User role
assigned in vSphere or VirtualCenter.
If your setup meets all these conditions, you can enable SSPI authentication by setting USERNAME to __sspi__.
For SSPI, the password must be set, but it is ignored. It can be set to "" (null).
Always call VixDiskLib_Disconnect() before the end of your program.
VMX Specification
On VMware platform products, .vmx is a text file (usually located in the same directory as virtual disk files)
specifying virtual machine configuration. The Virtual Machine eXecutable (VMX) process is the user‐space
component (or “world”) of a virtual machine. The virtual disk library connects to virtual machine storage
through the VMX process.
When specifying connection parameters (see “Data Structures in Virtual Disk API” on page 21) the preferred
syntax for vmxSpec is as follows:
Managed object reference of the virtual machine, an opaque object that you obtain programmatically
using the PropertyCollector managed object:
moRef=
The moRef of a virtual machine or disk snapshot on an ESX/ESXi host is likely different than the moRef of
the same virtual machine or disk snapshot as managed by vCenter Server. Here are two example moRef
specifications, one for ESXi and one for vCenter Server, both referring to the same snapshot:
moref=153
moref=271
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