Ensuring the integrity of installation data

Staging places increased demands on the integrity of installation data.
This makes the process of installing packages on the managed computer more secure.

• When preparing a package for distribution, an "integrity file" entitled Package.fpi which contains information about all package files is stored in the repository.
• Downloads onto the managed computer run in the background and therefore cannot be terminated "inadvertently".
• Interrupted downloads are automatically restarted and completed:
  Checkpoint Restart allows it to continue interrupted downloads exactly at the point in a file where the interruption took place.
• The source of the download can be switched independently by the DSM Client from one depot to another without impairing data integrity.
• The DSM Client also downloads the Package.fpi file containing the checksums of the package files onto the managed computers and checks prior to installation whether the package files in the repository cache have the same status as the package files on the depot.
  In addition, the Distribution Service stores the checksum of the package.fpi file in the additional file package.fpi.checksum (only in the original copy of the repository) and also in the DSMDB. From the DSMDB, the checksum is sent to the managed computer during the client synchronization and used there for an integrity check when downloading package files.
  If the files in the repository cache are not the same as on the depot, the respective files are downloaded again. If it is impossible to download the files again, the package is not installed. In any case, a message will be logged.

It is also ensured prior to installing package files that ...

• all data for the installation is available or can subsequently be loaded automatically.
  This ensures that an installation can always be completed and does not abort during this process.
• Exception: If the DSM Client cannot download the data into the repository cache.
  In this case, it attempts to perform the installation directly from the depot in accordance with the previously used method. The additional integrity check does not take place.