With the recent release of VMware View, one of the hottest components of the desktop virtualization component is the linked clone technology. In planning how VMware View works, it is important to understand the critical component – VMware View Composer.
VMware View Composer is simply a Windows service that resides on a vCenter server. VMware View Composer interacts with both vCenter and the View Connection Manager. For environments that already have a server based VMware environment with vCenter and ESX hosts, it is clear that a separate environment is a good idea. This would be best served through dedicated hosts, storage and a separate vCenter server. The figure below shows how the VMware View Composer and vCenter installations would work together:
The VMware View Composer service, or svid, interacts with vCenter from the configuration set forth from VMware View Connection manager, which functions as the broker for connections. Once the linked clone virtual desktops are created, they then deliver the storage optimization that we have been anticipating with the release of VMware View.
One other feature of View Composer is storage over-commit. This functionality is a configurable level of how the linked clones’ delta disk, or differencing disk, is allocated. Looking at a guest virtual machine, the delta disk would be a very small percentage of the parent or base VM. This setting will determine the behavior of determining how many VMs will fit on a datastore. A setting of conservative will enable less VMs to fit on a datastore, yet run less of a likelihood of running out of space. While a more aggressive level will attempt to put more VMs on the datastore and reserve less storage reserved for the delta disks. With that information, it is critically important to get an expectation of the delta disk behavior to best utilize the storage.
A final key component of View Composer is the Quickprep feature. Quickprep does the guest VM specific tasks such as domain membership, organizational unit placement in Active Directory and run any scripts on the guest VM.
With this information primer on VMware View Composer, it is important to isolate the vCenter and more importantly be aware of how the virtual desktop managment agents will interact with the vCenter server. More information on VMware View can be found on the VMware website.