General information

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What is the backup service?

The ITS backup service offers a centralized way of backing up data from workstations at the University of Kassel. In contrast to conventional methods (such as USB sticks or external hard disks), the data is stored on a central server with a large storage capacity.

The ITS backup service cannot completely replace a local backup on your computer, as absolute data security or constant availability cannot be guaranteed. However, it is a useful addition, as the backup can be automated on a daily basis with little effort.

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How does data backup work?

Data backup is based on the client-server principle. Software (client software) is installed on the future client computer (the computer from which the data is to be backed up). When setting up this software, the user selects the data to be backed up. The software transfers these files to the central server, which stores the data.

There are two options for backing up data:

The backup can be performed in two ways: automatically and/or manually. In both cases, the client software checks whether the files to be backed up have already been backed up or whether they have been changed. This means that the latest version of a file is always backed up. The client software sends these files to the server, which writes them to disks in a RAID system. If data has been changed, two older file versions are always retained so that the last three file versions can always be restored.

Archiving corresponds to temporary data storage. In this process, a snapshot of all stored hard disk data, i.e. a complete copy of the data stock, is taken. The storage of such data can range from a few months to several years. The archived data is automatically deleted after a set period has expired.

Backup archiving is not currently offered by the University of Kassel.

Software used - IBM Storage Protect

ITS uses the IBM Storage Protect program (formerly known as IBM Spectrum Protect Server or Tivoli Storage Manager) for data backup. With this software, user data can be reliably backed up or archived. The backed-up data is stored on fast, central storage (magnetic disks).

Additional information about the backed-up data, such as access rights or the storage location, is managed in a separate database. IBM Storage Protect works according to the client-server principle: the client is the computer whose data is to be backed up or restored. The software works independently of the operating system and behaves similarly on all platforms. The client identifies the data to be backed up and transfers it to the backup server via the network.

Further information on instructions, etc. can be found under Installation, configuration and automatic backup.

Strategies used for data backup

The strategies currently implemented may change in the medium term due to bottlenecks or limits to the available storage capacity.

The user-controlled backup can be used during the general operating hours of the servers. The user can access all the data during this time.

Retention periods

The following retention periods currently apply:

  • Backup
    • A completed backup is currently stored indefinitely. However, in order to keep the backup up to date, we recommend that you update your backup constantly (daily).
  • Changed files
    • In the case of modified files, up to 3 versions of a file are generally kept. The latest (active version) and the last 2 versions (inactive versions) of a file are retained. If a file becomes inactive, it is automatically deleted after 120 days or replaced by a newer version if necessary.
  • Deleted files
    • Files that have been deleted on the client computer are kept for 120 days.