In a VMware View environment you can either use Microsoft Sysprep or VMware Quickprep for the personalization of your Linked Clone desktop pools, while you can only use Sysprep for the personalization of traditional desktop pools based on VM templates. This article discusses the differences.
The VMware Quickprep tools which comes with VMware View is used for the same reason but only with Linked Clone desktop pools. Quickprep is faster compared to Sysprep as is does not change all files on the hard disk. It does change the SID in the Active Directory which is only used as described above. The Quickprep process is started by the View Composer during the creation of the Linked Clones. After the View Composer has created the replica disk and the Linked Clone own OS disk is mounted, the View Composer communicated with the Active Directory and creates a new computer account for the Linked Clone desktop and sets a random password. This process uses the standard Windows API interface and also the user account you’ve configured for the View Composer in the View Administrator GUI. If the configured user account does not have sufficient permissions the action will fail. If the action is successful, a configuration file which includes information about the desktop (hostname, domain and more) is created on the OS disk of the Linked Clone. After the file is written the desktops gets restarted. During the next boot process the View Agent hooks in. It does that in two modes. Firstly it runs in the native mode just before the Win32 subsystem is started. During that time it can still access system files which are usually locked. Secondly it starts the Service Agent which does the most tasks i.e. the communication with the View Server or writing to the Windows Registry. The native part of the agent reads the information which is written in the configuration file by the View Composer before and sets the hostname for the Windows operating system before the system comes up. After that the Service Agent writes the needed Windows domain information into the Registry.
If you’re choosing Sysprep for your Linked Clone desktops please consider the following points.
- All vSphere servers in your cluster must run a 4.0 or 4.1 version.
- A recompose does force the system to create a new SID. (That takes a long time depending on the number of files in the VM)
- The View Agent on the VM needs the View Composer component to be installed. (Usually this is the standard)
- The Active Directory controllers must be reachable from all the desktops.