4.6

Configuring an HTTP Cache to Provision Local Desktops Over a WAN
You can use an HTTP cache to facilitate the provisioning of linked-clone, local desktops. Configuring an HTTP
cache benefits remote offices and branch offices that are connected to the datacenter over a WAN. The HTTP
cache reduces the performance cost of transferring View Composer base images over a WAN.
If you configure linked-clone desktops to use local mode at remote offices, your WAN might not have the
bandwidth to efficiently download the View Composer base image directly to each local computer. For
example, repeatedly transferring a 6GB base image might be prohibitive.
If you set up an HTTP cache, the base image is stored in the proxy server's cache when the first user checks
out a desktop. When subsequent users check out desktops, the base image is transferred over the LAN within
the local office.
To complete a check-out operation, View Transfer Server still must transfer each user's linked-clone OS disk
and persistent disk from the datacenter over the WAN, but these disks are a fraction of the size of the base
image.
1 Configure View Connection Server to Support HTTP Caching of View Composer Base Images on
page 247
To allow a caching proxy server to pass on View Composer base images and other data between local
desktops and the datacenter, you must configure certain settings in View Connection Server.
2 Limit the Size of Base-Image Package Files to Allow Caching on page 248
A View Composer base-image package can contain files that are larger than a gigabyte, too large for
many proxy servers to cache. You can configure View Transfer Server to split base-image packages into
files that are no larger than the capacity of the proxy-server cache.
3 Configure Client Computers to Transfer Data Through a Proxy Server on page 249
To support HTTP caching, you must configure the client computers that host local desktops to transfer
the desktop data through a caching proxy server. You also must configure the client computers to use
the proxy server's HTTP address for internet connections.
4 Configure a Proxy Server to Cache View Composer Base Images on page 249
When you set up a proxy server to support HTTP caching for local desktops, you must configure the
capacity of the cache and the HTTP connection method.
Configure View Connection Server to Support HTTP Caching of View Composer
Base Images
To allow a caching proxy server to pass on View Composer base images and other data between local desktops
and the datacenter, you must configure certain settings in View Connection Server.
You use two separate View settings to configure SSL encryption for the following two types of data:
n
View Composer base images
n
Other linked-clone desktop data, including OS disks and persistent disks
You must disable SSL encryption of transfers of base-image package files from the Transfer Server repository
to local computers. Disabling SSL allows the proxy server to access and cache the package-file contents.
Disabling SSL does not expose the base-image data. The data is encrypted when you publish the base image
to the Transfer Server repository and remains encrypted when it is downloaded to the proxy server over the
WAN.
You can choose whether to use SSL encryption of transfers of all other local-desktop data. To permit other
local-desktop data to pass through the caching proxy server, you must configure the proxy server to allow the
use of the HTTP CONNECT method or you must enable SSL encryption of local-mode operations on View
Connection Server.
Chapter 13 Managing Local Desktops
VMware, Inc. 247