When creating a software distribution package, one available option for administrators is to store compressed versions of the package source files on the site server. When defining a location for storing a compressed source file, the folder/drive must be formatted as NTFS, as the FAT format will not support compressed package source files.

Before creating a package for distribution by Configuration Manager 2007, it is important that you verify that enough disk space is available on the site server and on distribution points (and on any required child site servers).

When you are distributing a package within a site, the following general guidelines will help you to compute the disk space required on a site server:

• If Configuration Manager 2007 will use the source files directly when distributing the package and the site server performs the distribution point role, the site server needs disk space equal to the size of the package.
  
  
• If the package will be sent to child sites, the site server needs additional disk space equal to 0.5 times the size of the package.
  
  
• If you store a compressed version of the source files, the site server needs additional disk space equal to 1.5 times the size of the original source files.
  
  
• Each distribution point requires disk space equal to approximately equal to 1.1 times the size of the uncompressed package source folder. This is necessarily because the distribution stores not only the package source folder but a delta signature recording changes to the folder as well.
  
  
• If the site server performs a distribution point role, it generally needs disk space between 1.0 and 2.5 times the size of the original package source files.
  
  

Software distribution will be quickest and most efficient if you have enough disk space to compress and decompress files. If there is not enough space, the site server will have to wait for the removal of temporary package directories before it can proceed with distributing the packages.

If a system runs out of disk space during the software distribution process, the Configuration Manager 2007 services will continue to try to complete the package compression and decompression. However, you should free the recommended amount of disk space. If free disk space can be made available before Configuration Manager 2007 services time out, Configuration Manager 2007 components will complete the actions that were prevented by a lack of disk space.

Note
When using a branch distribution point, you can configure the amount of disk space available using the ConfigMgr Distribution Point Properties dialog box. For more information, see ConfigMgr Distribution Point Properties: General Tab.

Some prerequisites do exist that must be taken into account when utilizing either standard or branch distribution points for software distribution.

Note
These prerequisites are required by the appropriate distribution point in order to permit it to function properly. In some cases, it is still possible to create a distribution point without conforming to one or more of these requirements. Such a distribution point will, however, not function properly on a Configuration Manager 2007 site.

Prerequisites for this Distribution Point type	Standard Distribution Point	Branch Distribution Point
Operating System type allowed	Server class operating systems (for more information on configuration requirements, see Configuration Manager Supported Configurations).	Server and workstation-class operating systems (for more information configuration requirements, see Configuration Manager Supported Configurations). Note Windows 2000 SP4 clients cannot be used as branch distribution points.
Must this distribution point be a Configuration Manager client?	No	Yes, and it must be successfully assigned to the site. Note To be a branch distribution point, it must be a Configuration Manager 2007 client; an SMS 2003 client cannot be used. Additionally, the client must not be configured for Internet-based client management.
Must the hosting computer be domain-joined?	Yes	Yes
Can the hosting computer be workgroup-joined?	No	No
Must IIS be installed?	No (Yes if BITS is enabled)*	No
Must there be a standard distribution point installed?	No	Yes, there must be a standard distribution point in the hierarchy that is configured for BITS and from which the branch distribution point can download assigned packages.
Must Remote Differential Compression (RDC) be installed?	No	Yes.*

*You must download, install, and configure WebDAV manually on BITS-enabled distribution points running Windows Server 2008. Branch distribution points require RDC to generate package signatures and perform signature comparison. RDC is not installed by default on computers running Windows Server 2008. For more information, see How to Configure Windows Server 2008 for Site Systems.

The following information applies only to Configuration Manager 2007 R2.

You must install the Microsoft Application Virtualization Client software on Configuration Manager 2007 clients to run virtual application packages in Configuration Manager 2007. The following table lists the dependencies for virtual application packages. If you plan to stream virtual application packages, the supported operating systems for the Application Virtualization Streaming enabled distribution point is also listed.