Archive for the ‘View Composer’ tag
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.
Every Windows operating system is generating a unique SID (Security Identifier) during the first installation of the system. This SID is used to clearly identify the operating system in a network environment. But this local SID is only used until the computer is a member is a Windows Workgroup only. As soon as you add the computer to a Active Directory domain a new SID for the computer account will be created and the local SID is no longer in use. The Microsoft Sysprep tool does change the SID for the operating system as the SID should be unique for each OS instance. The Sysprep operation needs several minutes to change the SID on a Windows OS as it needs to change all files on the hard disk drive.
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.
Also other software vendors use their own tools to change the SID on Windows instances, especially companies from the software deployment, like Altiris.
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.
Both applications, Sysprep and Quickprep give you the same result: A Windows desktops with a unique SID.
It’s a good decision to choose Quickprep for the Linked Clone pools because the personalization process is faster but there are also reasons for choosing Sysprep. Sometimes software products i.e. Antivirus software or network access control need a unique local SID. But anyway using vShield Endpoint is better than having a anti virus scanner in each desktop.
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.
Since View 4.5 it is possible to use several settings to get more speed into the provisioning tasks of View Composer. Even if the changes speed up your VDI environment please bear in mind that manual changes in the ADAM are not supported.
On the VMware forums some people report issues during the database setup for View Composer 2.0 when using teh component on a x64 Windows operating system. The installation drops a message saying: Database not found. User vBaw now posted a workaround which helps to install the Composer on a x64 vCenter Server.
Today I’ve found an question in the VMware Enterprise Desktop online community forums where a member asked if someone could explain the difference between the terms Reset, Refresh, Recompose and Rebalance in context of VMware View. Some of you are familiar with that but I think it’s worth to explain.
VMware View 3.1 offers a new function which helps you to automate the View Composer and View Manager ADAM database backup. Backup is often a part in IT which people forget about and just remember if it is already to late. In a View environment you can have two or three databases depending on the View license.
People asked me very often how exactly VMware View Composer does work, what’s the Replica image, what’s the source VM seen in the vCenter and much more. Today I found an interesting article from VMware vExpert Rodos which he has written on his blog site Musing of Rodos.
Recently I wrote an article about the handling of client mapped drives when using VMware View. RDP supports the redirection of the clients drives which will be forwarded to the virtual client and shown as network drives. With an GPO template which is included in View or the default Active Directory policy you can control this mapping. But what if the drive is a local drive like the OS disk in a automated linked clone pool?
The View Composer brings the linked clone technology to the View solution. Due to that the environment will need less storage for the virtual desktops. Form a technical View the Parent VM and the Snapshot will be combined as one VM or Entity. The virtual machine will be protected from deleting in the vCenter due to different linked clones a referencing to it.
With VMware View 3 and the View Composer it is possible to create automated desktop pools using the linked clone technology and saving storage through that. Within the configuration you can directly set an organizational unit in the Active Directory for the desktops in the automated desktop pool.