Creating Uncompressed Archives

For the purpose of long-term data preservation, archive files should always be submitted to TUdatalib in uncompressed form. The reason is that compression poses a risk to the long-term readability of digital data. For example, a bit flip (an unintentional change in the value of a single bit) can cause the complete loss of data in a compressed archive, whereas with an uncompressed archive, in the worst case only one file is lost.

Archive Types

• .tar archives are uncompressed by default. Please do not compress them afterward by creating a .tar.gz, .tgz, .tar.bzip, or similar file.
• .zip and .7z allow the creation of both compressed and uncompressed archives.

Creating Uncompressed .zip Archives with 7-Zip (Windows)

The following guide shows an example of how to create an uncompressed .zip file from a folder in 7-Zip. The guide was created on Windows 11 using 7-Zip version 26.00. 7-Zip is free software and available at https://www.7-zip.org.

Step 1: Open 7-Zip from the Context Menu

Right-click the folder from which you want to create the archive. If necessary, select "Show more options." Under "7-Zip," choose the option "Add to archive..."

Step 2: Set ZIP Parameters and Create the Archive

In the menu that appears, select "zip" as the archive format and "0 - Store" as the compression level. Then click "OK."

Step 3: Verify the Archive (Optional)

If you open the newly created .zip file, all entries should show "store" as the method, and the size and packed size should be identical.

Creating Uncompressed .zip Archives with 7-Zip (Linux)

When using 7-Zip via the Linux command line, set the -mx0 parameter to ensure that archives are not compressed.