2009-05-20

How do we refresh a package located on a Branch Distribution Point?

http://blogs.technet.com/carlossantiago/archive/2008/05/16/how-do-we-refresh-a-package-located-on-a-branch-distribution-point.aspx

The short answer is, we can't. That does not mean that we don't have a way to update that package on the Branch Distribution Point (BDP), it just means that we can't refresh them. In SCCM refreshing vs. updating a package has different meanings. When we run the Manage Distribution Points Wizard and select the option to refresh a package on distribution points, we are asking the Distribution Manager service to use the existing compressed version of the package and extract it to the specified distribution points. This is true unless we used the always obtain files from source option on the package properties. When we select the option to update a package, we are asking Distribution Manager to get the files from the source directory, create a new compressed version of the package, possibly send the compressed version to child sites, and then extract the new version to the distribution points. If you are wondering when should we use a refresh vs. an update think about the following scenarios:
Scenario #1
There is a central site in your headquarters office (NY) with primary child sites on remote offices. Software packages are created on the central site. There is a slow WAN connection between the central site and the child sites. One of the child sites is in Dallas and has distribution points in Dallas, Austin, and Houston. There is a hard drive failure on the Houston distribution point and a new hard drive is installed. There is no backup of the hard drive that was replaced since it only contained SCCM packages.

Scenario #2
There is a central site in your headquarters office (NY) with primary child sites on remote offices. Software packages are created on the central site. There is a slow WAN connection between the central site and the child sites. One of the child sites is in Dallas and has distribution points in Dallas, Austin, and Houston. The signature files for the antivirus application used by the company got updated. We updated the package source files and now need to get those files to the distribution points.
In Scenario #1, we could use the refresh package on the Houston distribution point option. The central site server will send an instruction to distribution manager on the Dallas site to extract the local compressed version of the package to the Houston distribution point. This will save time and traffic across the WAN link. In Scenario #2, we need to get new files for a package to the distribution points. In that case we need a new version of the compressed package to be sent over the WAN to the child sites. Distribution Manager on the Dallas child site will get the new compressed package and will then extract it to its local distribution point and the the ones in Austin and Houston.
The above is a very simplified explanation of what happens behind the scenes and I am not going to get in the details of delta replication. That is because this blog is about BDPs, so lets get back on track. If we run the Manage Distribution Points Wizard the first thing we are going to find out if we try to refresh a package on a BDP is that they are not listed in the Wizard. There is no refresh option for the BDPs because distribution manager does not handle packages on BDPs. The BDP role is a client side role. The BDP gets machine policies that tell the client what packages to download and share. Let say that in scenarios #1 and #2 the Houston distribution point is a BDP. In that case the refresh will not work obviously because it is not an option in the admin console. On scenario #1, to get the packages back on the Houston BDP we would have to use update option. On scenario #2, we would also get the new signature files to the Houston BDP by selecting to update the package on the distribution points.

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